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Inspired by a September 14, 2006 Salon article "Why Johnny Can't Code" by
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David Brin (http://www.salon.com/tech/feature/2006/09/14/basic/index.html),
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I thought that a fully working BASIC interpreter might be an interesting,
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if not questionable, PLY example. Uh, okay, so maybe it's just a bad idea,
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but in any case, here it is.
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In this example, you'll find a rough implementation of 1964 Dartmouth BASIC
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as described in the manual at:
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http://www.bitsavers.org/pdf/dartmouth/BASIC_Oct64.pdf
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See also:
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http://en.wikipedia.org/wiki/Dartmouth_BASIC
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This dialect is downright primitive---there are no string variables
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and no facilities for interactive input. Moreover, subroutines and functions
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are brain-dead even more than they usually are for BASIC. Of course,
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the GOTO statement is provided.
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Nevertheless, there are a few interesting aspects of this example:
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- It illustrates a fully working interpreter including lexing, parsing,
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and interpretation of instructions.
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- The parser shows how to catch and report various kinds of parsing
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errors in a more graceful way.
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- The example both parses files (supplied on command line) and
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interactive input entered line by line.
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- It shows how you might represent parsed information. In this case,
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each BASIC statement is encoded into a Python tuple containing the
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statement type and parameters. These tuples are then stored in
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a dictionary indexed by program line numbers.
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- Even though it's just BASIC, the parser contains more than 80
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rules and 150 parsing states. Thus, it's a little more meaty than
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the calculator example.
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To use the example, run it as follows:
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% python basic.py hello.bas
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HELLO WORLD
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%
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or use it interactively:
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% python basic.py
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[BASIC] 10 PRINT "HELLO WORLD"
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[BASIC] 20 END
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[BASIC] RUN
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HELLO WORLD
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[BASIC]
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The following files are defined:
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basic.py - High level script that controls everything
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basiclex.py - BASIC tokenizer
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basparse.py - BASIC parser
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basinterp.py - BASIC interpreter that runs parsed programs.
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In addition, a number of sample BASIC programs (.bas suffix) are
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provided. These were taken out of the Dartmouth manual.
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Disclaimer: I haven't spent a ton of time testing this and it's likely that
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I've skimped here and there on a few finer details (e.g., strictly enforcing
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variable naming rules). However, the interpreter seems to be able to run
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the examples in the BASIC manual.
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Have fun!
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-Dave
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# An implementation of Dartmouth BASIC (1964)
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#
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import sys
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sys.path.insert(0, "../..")
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if sys.version_info[0] >= 3:
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raw_input = input
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import basiclex
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import basparse
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import basinterp
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# If a filename has been specified, we try to run it.
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# If a runtime error occurs, we bail out and enter
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# interactive mode below
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if len(sys.argv) == 2:
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data = open(sys.argv[1]).read()
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prog = basparse.parse(data)
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if not prog:
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raise SystemExit
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b = basinterp.BasicInterpreter(prog)
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try:
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b.run()
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raise SystemExit
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except RuntimeError:
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pass
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else:
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b = basinterp.BasicInterpreter({})
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# Interactive mode. This incrementally adds/deletes statements
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# from the program stored in the BasicInterpreter object. In
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# addition, special commands 'NEW','LIST',and 'RUN' are added.
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# Specifying a line number with no code deletes that line from
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# the program.
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while 1:
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try:
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line = raw_input("[BASIC] ")
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except EOFError:
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raise SystemExit
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if not line:
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continue
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line += "\n"
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prog = basparse.parse(line)
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if not prog:
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continue
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keys = list(prog)
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if keys[0] > 0:
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b.add_statements(prog)
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else:
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stat = prog[keys[0]]
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if stat[0] == 'RUN':
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try:
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b.run()
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except RuntimeError:
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pass
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elif stat[0] == 'LIST':
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b.list()
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elif stat[0] == 'BLANK':
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b.del_line(stat[1])
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elif stat[0] == 'NEW':
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b.new()
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# An implementation of Dartmouth BASIC (1964)
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from ply import *
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keywords = (
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'LET', 'READ', 'DATA', 'PRINT', 'GOTO', 'IF', 'THEN', 'FOR', 'NEXT', 'TO', 'STEP',
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'END', 'STOP', 'DEF', 'GOSUB', 'DIM', 'REM', 'RETURN', 'RUN', 'LIST', 'NEW',
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)
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tokens = keywords + (
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'EQUALS', 'PLUS', 'MINUS', 'TIMES', 'DIVIDE', 'POWER',
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'LPAREN', 'RPAREN', 'LT', 'LE', 'GT', 'GE', 'NE',
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'COMMA', 'SEMI', 'INTEGER', 'FLOAT', 'STRING',
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'ID', 'NEWLINE'
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)
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t_ignore = ' \t'
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def t_REM(t):
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r'REM .*'
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return t
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def t_ID(t):
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r'[A-Z][A-Z0-9]*'
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if t.value in keywords:
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t.type = t.value
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return t
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t_EQUALS = r'='
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t_PLUS = r'\+'
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t_MINUS = r'-'
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t_TIMES = r'\*'
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t_POWER = r'\^'
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t_DIVIDE = r'/'
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t_LPAREN = r'\('
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t_RPAREN = r'\)'
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t_LT = r'<'
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t_LE = r'<='
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t_GT = r'>'
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t_GE = r'>='
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t_NE = r'<>'
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t_COMMA = r'\,'
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t_SEMI = r';'
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t_INTEGER = r'\d+'
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t_FLOAT = r'((\d*\.\d+)(E[\+-]?\d+)?|([1-9]\d*E[\+-]?\d+))'
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t_STRING = r'\".*?\"'
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def t_NEWLINE(t):
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r'\n'
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t.lexer.lineno += 1
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return t
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def t_error(t):
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print("Illegal character %s" % t.value[0])
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t.lexer.skip(1)
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lex.lex(debug=0)
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# An implementation of Dartmouth BASIC (1964)
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#
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import sys
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sys.path.insert(0, "../..")
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if sys.version_info[0] >= 3:
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raw_input = input
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import logging
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logging.basicConfig(
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level=logging.INFO,
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filename="parselog.txt",
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filemode="w"
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)
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log = logging.getLogger()
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import basiclex
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import basparse
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import basinterp
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# If a filename has been specified, we try to run it.
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# If a runtime error occurs, we bail out and enter
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# interactive mode below
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if len(sys.argv) == 2:
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data = open(sys.argv[1]).read()
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prog = basparse.parse(data, debug=log)
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if not prog:
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raise SystemExit
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b = basinterp.BasicInterpreter(prog)
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try:
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b.run()
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raise SystemExit
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except RuntimeError:
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pass
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else:
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b = basinterp.BasicInterpreter({})
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# Interactive mode. This incrementally adds/deletes statements
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# from the program stored in the BasicInterpreter object. In
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# addition, special commands 'NEW','LIST',and 'RUN' are added.
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# Specifying a line number with no code deletes that line from
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# the program.
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while 1:
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try:
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line = raw_input("[BASIC] ")
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except EOFError:
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raise SystemExit
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if not line:
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continue
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line += "\n"
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prog = basparse.parse(line, debug=log)
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if not prog:
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continue
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keys = list(prog)
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if keys[0] > 0:
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b.add_statements(prog)
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else:
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stat = prog[keys[0]]
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if stat[0] == 'RUN':
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try:
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b.run()
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except RuntimeError:
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pass
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elif stat[0] == 'LIST':
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b.list()
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elif stat[0] == 'BLANK':
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b.del_line(stat[1])
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elif stat[0] == 'NEW':
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b.new()
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@ -0,0 +1,496 @@
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# This file provides the runtime support for running a basic program
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# Assumes the program has been parsed using basparse.py
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import sys
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import math
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import random
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class BasicInterpreter:
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# Initialize the interpreter. prog is a dictionary
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# containing (line,statement) mappings
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def __init__(self, prog):
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self.prog = prog
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self.functions = { # Built-in function table
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'SIN': lambda z: math.sin(self.eval(z)),
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'COS': lambda z: math.cos(self.eval(z)),
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'TAN': lambda z: math.tan(self.eval(z)),
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'ATN': lambda z: math.atan(self.eval(z)),
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'EXP': lambda z: math.exp(self.eval(z)),
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'ABS': lambda z: abs(self.eval(z)),
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'LOG': lambda z: math.log(self.eval(z)),
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'SQR': lambda z: math.sqrt(self.eval(z)),
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'INT': lambda z: int(self.eval(z)),
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'RND': lambda z: random.random()
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}
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# Collect all data statements
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def collect_data(self):
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self.data = []
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for lineno in self.stat:
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if self.prog[lineno][0] == 'DATA':
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self.data = self.data + self.prog[lineno][1]
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self.dc = 0 # Initialize the data counter
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# Check for end statements
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def check_end(self):
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has_end = 0
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for lineno in self.stat:
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if self.prog[lineno][0] == 'END' and not has_end:
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has_end = lineno
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if not has_end:
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print("NO END INSTRUCTION")
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self.error = 1
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return
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if has_end != lineno:
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print("END IS NOT LAST")
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self.error = 1
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# Check loops
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def check_loops(self):
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for pc in range(len(self.stat)):
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lineno = self.stat[pc]
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if self.prog[lineno][0] == 'FOR':
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forinst = self.prog[lineno]
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loopvar = forinst[1]
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for i in range(pc + 1, len(self.stat)):
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if self.prog[self.stat[i]][0] == 'NEXT':
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nextvar = self.prog[self.stat[i]][1]
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if nextvar != loopvar:
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continue
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self.loopend[pc] = i
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break
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else:
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print("FOR WITHOUT NEXT AT LINE %s" % self.stat[pc])
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self.error = 1
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# Evaluate an expression
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def eval(self, expr):
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etype = expr[0]
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if etype == 'NUM':
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return expr[1]
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elif etype == 'GROUP':
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return self.eval(expr[1])
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elif etype == 'UNARY':
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if expr[1] == '-':
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return -self.eval(expr[2])
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elif etype == 'BINOP':
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if expr[1] == '+':
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return self.eval(expr[2]) + self.eval(expr[3])
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elif expr[1] == '-':
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return self.eval(expr[2]) - self.eval(expr[3])
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elif expr[1] == '*':
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return self.eval(expr[2]) * self.eval(expr[3])
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elif expr[1] == '/':
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return float(self.eval(expr[2])) / self.eval(expr[3])
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elif expr[1] == '^':
|
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return abs(self.eval(expr[2]))**self.eval(expr[3])
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elif etype == 'VAR':
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var, dim1, dim2 = expr[1]
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if not dim1 and not dim2:
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if var in self.vars:
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return self.vars[var]
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else:
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print("UNDEFINED VARIABLE %s AT LINE %s" %
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(var, self.stat[self.pc]))
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raise RuntimeError
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# May be a list lookup or a function evaluation
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if dim1 and not dim2:
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if var in self.functions:
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# A function
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||||
return self.functions[var](dim1)
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||||
else:
|
||||
# A list evaluation
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||||
if var in self.lists:
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dim1val = self.eval(dim1)
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if dim1val < 1 or dim1val > len(self.lists[var]):
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print("LIST INDEX OUT OF BOUNDS AT LINE %s" %
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self.stat[self.pc])
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raise RuntimeError
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||||
return self.lists[var][dim1val - 1]
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||||
if dim1 and dim2:
|
||||
if var in self.tables:
|
||||
dim1val = self.eval(dim1)
|
||||
dim2val = self.eval(dim2)
|
||||
if dim1val < 1 or dim1val > len(self.tables[var]) or dim2val < 1 or dim2val > len(self.tables[var][0]):
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||||
print("TABLE INDEX OUT OUT BOUNDS AT LINE %s" %
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self.stat[self.pc])
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raise RuntimeError
|
||||
return self.tables[var][dim1val - 1][dim2val - 1]
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||||
print("UNDEFINED VARIABLE %s AT LINE %s" %
|
||||
(var, self.stat[self.pc]))
|
||||
raise RuntimeError
|
||||
|
||||
# Evaluate a relational expression
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||||
def releval(self, expr):
|
||||
etype = expr[1]
|
||||
lhs = self.eval(expr[2])
|
||||
rhs = self.eval(expr[3])
|
||||
if etype == '<':
|
||||
if lhs < rhs:
|
||||
return 1
|
||||
else:
|
||||
return 0
|
||||
|
||||
elif etype == '<=':
|
||||
if lhs <= rhs:
|
||||
return 1
|
||||
else:
|
||||
return 0
|
||||
|
||||
elif etype == '>':
|
||||
if lhs > rhs:
|
||||
return 1
|
||||
else:
|
||||
return 0
|
||||
|
||||
elif etype == '>=':
|
||||
if lhs >= rhs:
|
||||
return 1
|
||||
else:
|
||||
return 0
|
||||
|
||||
elif etype == '=':
|
||||
if lhs == rhs:
|
||||
return 1
|
||||
else:
|
||||
return 0
|
||||
|
||||
elif etype == '<>':
|
||||
if lhs != rhs:
|
||||
return 1
|
||||
else:
|
||||
return 0
|
||||
|
||||
# Assignment
|
||||
def assign(self, target, value):
|
||||
var, dim1, dim2 = target
|
||||
if not dim1 and not dim2:
|
||||
self.vars[var] = self.eval(value)
|
||||
elif dim1 and not dim2:
|
||||
# List assignment
|
||||
dim1val = self.eval(dim1)
|
||||
if not var in self.lists:
|
||||
self.lists[var] = [0] * 10
|
||||
|
||||
if dim1val > len(self.lists[var]):
|
||||
print ("DIMENSION TOO LARGE AT LINE %s" % self.stat[self.pc])
|
||||
raise RuntimeError
|
||||
self.lists[var][dim1val - 1] = self.eval(value)
|
||||
elif dim1 and dim2:
|
||||
dim1val = self.eval(dim1)
|
||||
dim2val = self.eval(dim2)
|
||||
if not var in self.tables:
|
||||
temp = [0] * 10
|
||||
v = []
|
||||
for i in range(10):
|
||||
v.append(temp[:])
|
||||
self.tables[var] = v
|
||||
# Variable already exists
|
||||
if dim1val > len(self.tables[var]) or dim2val > len(self.tables[var][0]):
|
||||
print("DIMENSION TOO LARGE AT LINE %s" % self.stat[self.pc])
|
||||
raise RuntimeError
|
||||
self.tables[var][dim1val - 1][dim2val - 1] = self.eval(value)
|
||||
|
||||
# Change the current line number
|
||||
def goto(self, linenum):
|
||||
if not linenum in self.prog:
|
||||
print("UNDEFINED LINE NUMBER %d AT LINE %d" %
|
||||
(linenum, self.stat[self.pc]))
|
||||
raise RuntimeError
|
||||
self.pc = self.stat.index(linenum)
|
||||
|
||||
# Run it
|
||||
def run(self):
|
||||
self.vars = {} # All variables
|
||||
self.lists = {} # List variables
|
||||
self.tables = {} # Tables
|
||||
self.loops = [] # Currently active loops
|
||||
self.loopend = {} # Mapping saying where loops end
|
||||
self.gosub = None # Gosub return point (if any)
|
||||
self.error = 0 # Indicates program error
|
||||
|
||||
self.stat = list(self.prog) # Ordered list of all line numbers
|
||||
self.stat.sort()
|
||||
self.pc = 0 # Current program counter
|
||||
|
||||
# Processing prior to running
|
||||
|
||||
self.collect_data() # Collect all of the data statements
|
||||
self.check_end()
|
||||
self.check_loops()
|
||||
|
||||
if self.error:
|
||||
raise RuntimeError
|
||||
|
||||
while 1:
|
||||
line = self.stat[self.pc]
|
||||
instr = self.prog[line]
|
||||
|
||||
op = instr[0]
|
||||
|
||||
# END and STOP statements
|
||||
if op == 'END' or op == 'STOP':
|
||||
break # We're done
|
||||
|
||||
# GOTO statement
|
||||
elif op == 'GOTO':
|
||||
newline = instr[1]
|
||||
self.goto(newline)
|
||||
continue
|
||||
|
||||
# PRINT statement
|
||||
elif op == 'PRINT':
|
||||
plist = instr[1]
|
||||
out = ""
|
||||
for label, val in plist:
|
||||
if out:
|
||||
out += ' ' * (15 - (len(out) % 15))
|
||||
out += label
|
||||
if val:
|
||||
if label:
|
||||
out += " "
|
||||
eval = self.eval(val)
|
||||
out += str(eval)
|
||||
sys.stdout.write(out)
|
||||
end = instr[2]
|
||||
if not (end == ',' or end == ';'):
|
||||
sys.stdout.write("\n")
|
||||
if end == ',':
|
||||
sys.stdout.write(" " * (15 - (len(out) % 15)))
|
||||
if end == ';':
|
||||
sys.stdout.write(" " * (3 - (len(out) % 3)))
|
||||
|
||||
# LET statement
|
||||
elif op == 'LET':
|
||||
target = instr[1]
|
||||
value = instr[2]
|
||||
self.assign(target, value)
|
||||
|
||||
# READ statement
|
||||
elif op == 'READ':
|
||||
for target in instr[1]:
|
||||
if self.dc < len(self.data):
|
||||
value = ('NUM', self.data[self.dc])
|
||||
self.assign(target, value)
|
||||
self.dc += 1
|
||||
else:
|
||||
# No more data. Program ends
|
||||
return
|
||||
elif op == 'IF':
|
||||
relop = instr[1]
|
||||
newline = instr[2]
|
||||
if (self.releval(relop)):
|
||||
self.goto(newline)
|
||||
continue
|
||||
|
||||
elif op == 'FOR':
|
||||
loopvar = instr[1]
|
||||
initval = instr[2]
|
||||
finval = instr[3]
|
||||
stepval = instr[4]
|
||||
|
||||
# Check to see if this is a new loop
|
||||
if not self.loops or self.loops[-1][0] != self.pc:
|
||||
# Looks like a new loop. Make the initial assignment
|
||||
newvalue = initval
|
||||
self.assign((loopvar, None, None), initval)
|
||||
if not stepval:
|
||||
stepval = ('NUM', 1)
|
||||
stepval = self.eval(stepval) # Evaluate step here
|
||||
self.loops.append((self.pc, stepval))
|
||||
else:
|
||||
# It's a repeat of the previous loop
|
||||
# Update the value of the loop variable according to the
|
||||
# step
|
||||
stepval = ('NUM', self.loops[-1][1])
|
||||
newvalue = (
|
||||
'BINOP', '+', ('VAR', (loopvar, None, None)), stepval)
|
||||
|
||||
if self.loops[-1][1] < 0:
|
||||
relop = '>='
|
||||
else:
|
||||
relop = '<='
|
||||
if not self.releval(('RELOP', relop, newvalue, finval)):
|
||||
# Loop is done. Jump to the NEXT
|
||||
self.pc = self.loopend[self.pc]
|
||||
self.loops.pop()
|
||||
else:
|
||||
self.assign((loopvar, None, None), newvalue)
|
||||
|
||||
elif op == 'NEXT':
|
||||
if not self.loops:
|
||||
print("NEXT WITHOUT FOR AT LINE %s" % line)
|
||||
return
|
||||
|
||||
nextvar = instr[1]
|
||||
self.pc = self.loops[-1][0]
|
||||
loopinst = self.prog[self.stat[self.pc]]
|
||||
forvar = loopinst[1]
|
||||
if nextvar != forvar:
|
||||
print("NEXT DOESN'T MATCH FOR AT LINE %s" % line)
|
||||
return
|
||||
continue
|
||||
elif op == 'GOSUB':
|
||||
newline = instr[1]
|
||||
if self.gosub:
|
||||
print("ALREADY IN A SUBROUTINE AT LINE %s" % line)
|
||||
return
|
||||
self.gosub = self.stat[self.pc]
|
||||
self.goto(newline)
|
||||
continue
|
||||
|
||||
elif op == 'RETURN':
|
||||
if not self.gosub:
|
||||
print("RETURN WITHOUT A GOSUB AT LINE %s" % line)
|
||||
return
|
||||
self.goto(self.gosub)
|
||||
self.gosub = None
|
||||
|
||||
elif op == 'FUNC':
|
||||
fname = instr[1]
|
||||
pname = instr[2]
|
||||
expr = instr[3]
|
||||
|
||||
def eval_func(pvalue, name=pname, self=self, expr=expr):
|
||||
self.assign((pname, None, None), pvalue)
|
||||
return self.eval(expr)
|
||||
self.functions[fname] = eval_func
|
||||
|
||||
elif op == 'DIM':
|
||||
for vname, x, y in instr[1]:
|
||||
if y == 0:
|
||||
# Single dimension variable
|
||||
self.lists[vname] = [0] * x
|
||||
else:
|
||||
# Double dimension variable
|
||||
temp = [0] * y
|
||||
v = []
|
||||
for i in range(x):
|
||||
v.append(temp[:])
|
||||
self.tables[vname] = v
|
||||
|
||||
self.pc += 1
|
||||
|
||||
# Utility functions for program listing
|
||||
def expr_str(self, expr):
|
||||
etype = expr[0]
|
||||
if etype == 'NUM':
|
||||
return str(expr[1])
|
||||
elif etype == 'GROUP':
|
||||
return "(%s)" % self.expr_str(expr[1])
|
||||
elif etype == 'UNARY':
|
||||
if expr[1] == '-':
|
||||
return "-" + str(expr[2])
|
||||
elif etype == 'BINOP':
|
||||
return "%s %s %s" % (self.expr_str(expr[2]), expr[1], self.expr_str(expr[3]))
|
||||
elif etype == 'VAR':
|
||||
return self.var_str(expr[1])
|
||||
|
||||
def relexpr_str(self, expr):
|
||||
return "%s %s %s" % (self.expr_str(expr[2]), expr[1], self.expr_str(expr[3]))
|
||||
|
||||
def var_str(self, var):
|
||||
varname, dim1, dim2 = var
|
||||
if not dim1 and not dim2:
|
||||
return varname
|
||||
if dim1 and not dim2:
|
||||
return "%s(%s)" % (varname, self.expr_str(dim1))
|
||||
return "%s(%s,%s)" % (varname, self.expr_str(dim1), self.expr_str(dim2))
|
||||
|
||||
# Create a program listing
|
||||
def list(self):
|
||||
stat = list(self.prog) # Ordered list of all line numbers
|
||||
stat.sort()
|
||||
for line in stat:
|
||||
instr = self.prog[line]
|
||||
op = instr[0]
|
||||
if op in ['END', 'STOP', 'RETURN']:
|
||||
print("%s %s" % (line, op))
|
||||
continue
|
||||
elif op == 'REM':
|
||||
print("%s %s" % (line, instr[1]))
|
||||
elif op == 'PRINT':
|
||||
_out = "%s %s " % (line, op)
|
||||
first = 1
|
||||
for p in instr[1]:
|
||||
if not first:
|
||||
_out += ", "
|
||||
if p[0] and p[1]:
|
||||
_out += '"%s"%s' % (p[0], self.expr_str(p[1]))
|
||||
elif p[1]:
|
||||
_out += self.expr_str(p[1])
|
||||
else:
|
||||
_out += '"%s"' % (p[0],)
|
||||
first = 0
|
||||
if instr[2]:
|
||||
_out += instr[2]
|
||||
print(_out)
|
||||
elif op == 'LET':
|
||||
print("%s LET %s = %s" %
|
||||
(line, self.var_str(instr[1]), self.expr_str(instr[2])))
|
||||
elif op == 'READ':
|
||||
_out = "%s READ " % line
|
||||
first = 1
|
||||
for r in instr[1]:
|
||||
if not first:
|
||||
_out += ","
|
||||
_out += self.var_str(r)
|
||||
first = 0
|
||||
print(_out)
|
||||
elif op == 'IF':
|
||||
print("%s IF %s THEN %d" %
|
||||
(line, self.relexpr_str(instr[1]), instr[2]))
|
||||
elif op == 'GOTO' or op == 'GOSUB':
|
||||
print("%s %s %s" % (line, op, instr[1]))
|
||||
elif op == 'FOR':
|
||||
_out = "%s FOR %s = %s TO %s" % (
|
||||
line, instr[1], self.expr_str(instr[2]), self.expr_str(instr[3]))
|
||||
if instr[4]:
|
||||
_out += " STEP %s" % (self.expr_str(instr[4]))
|
||||
print(_out)
|
||||
elif op == 'NEXT':
|
||||
print("%s NEXT %s" % (line, instr[1]))
|
||||
elif op == 'FUNC':
|
||||
print("%s DEF %s(%s) = %s" %
|
||||
(line, instr[1], instr[2], self.expr_str(instr[3])))
|
||||
elif op == 'DIM':
|
||||
_out = "%s DIM " % line
|
||||
first = 1
|
||||
for vname, x, y in instr[1]:
|
||||
if not first:
|
||||
_out += ","
|
||||
first = 0
|
||||
if y == 0:
|
||||
_out += "%s(%d)" % (vname, x)
|
||||
else:
|
||||
_out += "%s(%d,%d)" % (vname, x, y)
|
||||
|
||||
print(_out)
|
||||
elif op == 'DATA':
|
||||
_out = "%s DATA " % line
|
||||
first = 1
|
||||
for v in instr[1]:
|
||||
if not first:
|
||||
_out += ","
|
||||
first = 0
|
||||
_out += v
|
||||
print(_out)
|
||||
|
||||
# Erase the current program
|
||||
def new(self):
|
||||
self.prog = {}
|
||||
|
||||
# Insert statements
|
||||
def add_statements(self, prog):
|
||||
for line, stat in prog.items():
|
||||
self.prog[line] = stat
|
||||
|
||||
# Delete a statement
|
||||
def del_line(self, lineno):
|
||||
try:
|
||||
del self.prog[lineno]
|
||||
except KeyError:
|
||||
pass
|
||||
|
|
@ -0,0 +1,474 @@
|
|||
# An implementation of Dartmouth BASIC (1964)
|
||||
#
|
||||
|
||||
from ply import *
|
||||
import basiclex
|
||||
|
||||
tokens = basiclex.tokens
|
||||
|
||||
precedence = (
|
||||
('left', 'PLUS', 'MINUS'),
|
||||
('left', 'TIMES', 'DIVIDE'),
|
||||
('left', 'POWER'),
|
||||
('right', 'UMINUS')
|
||||
)
|
||||
|
||||
# A BASIC program is a series of statements. We represent the program as a
|
||||
# dictionary of tuples indexed by line number.
|
||||
|
||||
|
||||
def p_program(p):
|
||||
'''program : program statement
|
||||
| statement'''
|
||||
|
||||
if len(p) == 2 and p[1]:
|
||||
p[0] = {}
|
||||
line, stat = p[1]
|
||||
p[0][line] = stat
|
||||
elif len(p) == 3:
|
||||
p[0] = p[1]
|
||||
if not p[0]:
|
||||
p[0] = {}
|
||||
if p[2]:
|
||||
line, stat = p[2]
|
||||
p[0][line] = stat
|
||||
|
||||
# This catch-all rule is used for any catastrophic errors. In this case,
|
||||
# we simply return nothing
|
||||
|
||||
|
||||
def p_program_error(p):
|
||||
'''program : error'''
|
||||
p[0] = None
|
||||
p.parser.error = 1
|
||||
|
||||
# Format of all BASIC statements.
|
||||
|
||||
|
||||
def p_statement(p):
|
||||
'''statement : INTEGER command NEWLINE'''
|
||||
if isinstance(p[2], str):
|
||||
print("%s %s %s" % (p[2], "AT LINE", p[1]))
|
||||
p[0] = None
|
||||
p.parser.error = 1
|
||||
else:
|
||||
lineno = int(p[1])
|
||||
p[0] = (lineno, p[2])
|
||||
|
||||
# Interactive statements.
|
||||
|
||||
|
||||
def p_statement_interactive(p):
|
||||
'''statement : RUN NEWLINE
|
||||
| LIST NEWLINE
|
||||
| NEW NEWLINE'''
|
||||
p[0] = (0, (p[1], 0))
|
||||
|
||||
# Blank line number
|
||||
|
||||
|
||||
def p_statement_blank(p):
|
||||
'''statement : INTEGER NEWLINE'''
|
||||
p[0] = (0, ('BLANK', int(p[1])))
|
||||
|
||||
# Error handling for malformed statements
|
||||
|
||||
|
||||
def p_statement_bad(p):
|
||||
'''statement : INTEGER error NEWLINE'''
|
||||
print("MALFORMED STATEMENT AT LINE %s" % p[1])
|
||||
p[0] = None
|
||||
p.parser.error = 1
|
||||
|
||||
# Blank line
|
||||
|
||||
|
||||
def p_statement_newline(p):
|
||||
'''statement : NEWLINE'''
|
||||
p[0] = None
|
||||
|
||||
# LET statement
|
||||
|
||||
|
||||
def p_command_let(p):
|
||||
'''command : LET variable EQUALS expr'''
|
||||
p[0] = ('LET', p[2], p[4])
|
||||
|
||||
|
||||
def p_command_let_bad(p):
|
||||
'''command : LET variable EQUALS error'''
|
||||
p[0] = "BAD EXPRESSION IN LET"
|
||||
|
||||
# READ statement
|
||||
|
||||
|
||||
def p_command_read(p):
|
||||
'''command : READ varlist'''
|
||||
p[0] = ('READ', p[2])
|
||||
|
||||
|
||||
def p_command_read_bad(p):
|
||||
'''command : READ error'''
|
||||
p[0] = "MALFORMED VARIABLE LIST IN READ"
|
||||
|
||||
# DATA statement
|
||||
|
||||
|
||||
def p_command_data(p):
|
||||
'''command : DATA numlist'''
|
||||
p[0] = ('DATA', p[2])
|
||||
|
||||
|
||||
def p_command_data_bad(p):
|
||||
'''command : DATA error'''
|
||||
p[0] = "MALFORMED NUMBER LIST IN DATA"
|
||||
|
||||
# PRINT statement
|
||||
|
||||
|
||||
def p_command_print(p):
|
||||
'''command : PRINT plist optend'''
|
||||
p[0] = ('PRINT', p[2], p[3])
|
||||
|
||||
|
||||
def p_command_print_bad(p):
|
||||
'''command : PRINT error'''
|
||||
p[0] = "MALFORMED PRINT STATEMENT"
|
||||
|
||||
# Optional ending on PRINT. Either a comma (,) or semicolon (;)
|
||||
|
||||
|
||||
def p_optend(p):
|
||||
'''optend : COMMA
|
||||
| SEMI
|
||||
|'''
|
||||
if len(p) == 2:
|
||||
p[0] = p[1]
|
||||
else:
|
||||
p[0] = None
|
||||
|
||||
# PRINT statement with no arguments
|
||||
|
||||
|
||||
def p_command_print_empty(p):
|
||||
'''command : PRINT'''
|
||||
p[0] = ('PRINT', [], None)
|
||||
|
||||
# GOTO statement
|
||||
|
||||
|
||||
def p_command_goto(p):
|
||||
'''command : GOTO INTEGER'''
|
||||
p[0] = ('GOTO', int(p[2]))
|
||||
|
||||
|
||||
def p_command_goto_bad(p):
|
||||
'''command : GOTO error'''
|
||||
p[0] = "INVALID LINE NUMBER IN GOTO"
|
||||
|
||||
# IF-THEN statement
|
||||
|
||||
|
||||
def p_command_if(p):
|
||||
'''command : IF relexpr THEN INTEGER'''
|
||||
p[0] = ('IF', p[2], int(p[4]))
|
||||
|
||||
|
||||
def p_command_if_bad(p):
|
||||
'''command : IF error THEN INTEGER'''
|
||||
p[0] = "BAD RELATIONAL EXPRESSION"
|
||||
|
||||
|
||||
def p_command_if_bad2(p):
|
||||
'''command : IF relexpr THEN error'''
|
||||
p[0] = "INVALID LINE NUMBER IN THEN"
|
||||
|
||||
# FOR statement
|
||||
|
||||
|
||||
def p_command_for(p):
|
||||
'''command : FOR ID EQUALS expr TO expr optstep'''
|
||||
p[0] = ('FOR', p[2], p[4], p[6], p[7])
|
||||
|
||||
|
||||
def p_command_for_bad_initial(p):
|
||||
'''command : FOR ID EQUALS error TO expr optstep'''
|
||||
p[0] = "BAD INITIAL VALUE IN FOR STATEMENT"
|
||||
|
||||
|
||||
def p_command_for_bad_final(p):
|
||||
'''command : FOR ID EQUALS expr TO error optstep'''
|
||||
p[0] = "BAD FINAL VALUE IN FOR STATEMENT"
|
||||
|
||||
|
||||
def p_command_for_bad_step(p):
|
||||
'''command : FOR ID EQUALS expr TO expr STEP error'''
|
||||
p[0] = "MALFORMED STEP IN FOR STATEMENT"
|
||||
|
||||
# Optional STEP qualifier on FOR statement
|
||||
|
||||
|
||||
def p_optstep(p):
|
||||
'''optstep : STEP expr
|
||||
| empty'''
|
||||
if len(p) == 3:
|
||||
p[0] = p[2]
|
||||
else:
|
||||
p[0] = None
|
||||
|
||||
# NEXT statement
|
||||
|
||||
|
||||
def p_command_next(p):
|
||||
'''command : NEXT ID'''
|
||||
|
||||
p[0] = ('NEXT', p[2])
|
||||
|
||||
|
||||
def p_command_next_bad(p):
|
||||
'''command : NEXT error'''
|
||||
p[0] = "MALFORMED NEXT"
|
||||
|
||||
# END statement
|
||||
|
||||
|
||||
def p_command_end(p):
|
||||
'''command : END'''
|
||||
p[0] = ('END',)
|
||||
|
||||
# REM statement
|
||||
|
||||
|
||||
def p_command_rem(p):
|
||||
'''command : REM'''
|
||||
p[0] = ('REM', p[1])
|
||||
|
||||
# STOP statement
|
||||
|
||||
|
||||
def p_command_stop(p):
|
||||
'''command : STOP'''
|
||||
p[0] = ('STOP',)
|
||||
|
||||
# DEF statement
|
||||
|
||||
|
||||
def p_command_def(p):
|
||||
'''command : DEF ID LPAREN ID RPAREN EQUALS expr'''
|
||||
p[0] = ('FUNC', p[2], p[4], p[7])
|
||||
|
||||
|
||||
def p_command_def_bad_rhs(p):
|
||||
'''command : DEF ID LPAREN ID RPAREN EQUALS error'''
|
||||
p[0] = "BAD EXPRESSION IN DEF STATEMENT"
|
||||
|
||||
|
||||
def p_command_def_bad_arg(p):
|
||||
'''command : DEF ID LPAREN error RPAREN EQUALS expr'''
|
||||
p[0] = "BAD ARGUMENT IN DEF STATEMENT"
|
||||
|
||||
# GOSUB statement
|
||||
|
||||
|
||||
def p_command_gosub(p):
|
||||
'''command : GOSUB INTEGER'''
|
||||
p[0] = ('GOSUB', int(p[2]))
|
||||
|
||||
|
||||
def p_command_gosub_bad(p):
|
||||
'''command : GOSUB error'''
|
||||
p[0] = "INVALID LINE NUMBER IN GOSUB"
|
||||
|
||||
# RETURN statement
|
||||
|
||||
|
||||
def p_command_return(p):
|
||||
'''command : RETURN'''
|
||||
p[0] = ('RETURN',)
|
||||
|
||||
# DIM statement
|
||||
|
||||
|
||||
def p_command_dim(p):
|
||||
'''command : DIM dimlist'''
|
||||
p[0] = ('DIM', p[2])
|
||||
|
||||
|
||||
def p_command_dim_bad(p):
|
||||
'''command : DIM error'''
|
||||
p[0] = "MALFORMED VARIABLE LIST IN DIM"
|
||||
|
||||
# List of variables supplied to DIM statement
|
||||
|
||||
|
||||
def p_dimlist(p):
|
||||
'''dimlist : dimlist COMMA dimitem
|
||||
| dimitem'''
|
||||
if len(p) == 4:
|
||||
p[0] = p[1]
|
||||
p[0].append(p[3])
|
||||
else:
|
||||
p[0] = [p[1]]
|
||||
|
||||
# DIM items
|
||||
|
||||
|
||||
def p_dimitem_single(p):
|
||||
'''dimitem : ID LPAREN INTEGER RPAREN'''
|
||||
p[0] = (p[1], eval(p[3]), 0)
|
||||
|
||||
|
||||
def p_dimitem_double(p):
|
||||
'''dimitem : ID LPAREN INTEGER COMMA INTEGER RPAREN'''
|
||||
p[0] = (p[1], eval(p[3]), eval(p[5]))
|
||||
|
||||
# Arithmetic expressions
|
||||
|
||||
|
||||
def p_expr_binary(p):
|
||||
'''expr : expr PLUS expr
|
||||
| expr MINUS expr
|
||||
| expr TIMES expr
|
||||
| expr DIVIDE expr
|
||||
| expr POWER expr'''
|
||||
|
||||
p[0] = ('BINOP', p[2], p[1], p[3])
|
||||
|
||||
|
||||
def p_expr_number(p):
|
||||
'''expr : INTEGER
|
||||
| FLOAT'''
|
||||
p[0] = ('NUM', eval(p[1]))
|
||||
|
||||
|
||||
def p_expr_variable(p):
|
||||
'''expr : variable'''
|
||||
p[0] = ('VAR', p[1])
|
||||
|
||||
|
||||
def p_expr_group(p):
|
||||
'''expr : LPAREN expr RPAREN'''
|
||||
p[0] = ('GROUP', p[2])
|
||||
|
||||
|
||||
def p_expr_unary(p):
|
||||
'''expr : MINUS expr %prec UMINUS'''
|
||||
p[0] = ('UNARY', '-', p[2])
|
||||
|
||||
# Relational expressions
|
||||
|
||||
|
||||
def p_relexpr(p):
|
||||
'''relexpr : expr LT expr
|
||||
| expr LE expr
|
||||
| expr GT expr
|
||||
| expr GE expr
|
||||
| expr EQUALS expr
|
||||
| expr NE expr'''
|
||||
p[0] = ('RELOP', p[2], p[1], p[3])
|
||||
|
||||
# Variables
|
||||
|
||||
|
||||
def p_variable(p):
|
||||
'''variable : ID
|
||||
| ID LPAREN expr RPAREN
|
||||
| ID LPAREN expr COMMA expr RPAREN'''
|
||||
if len(p) == 2:
|
||||
p[0] = (p[1], None, None)
|
||||
elif len(p) == 5:
|
||||
p[0] = (p[1], p[3], None)
|
||||
else:
|
||||
p[0] = (p[1], p[3], p[5])
|
||||
|
||||
# Builds a list of variable targets as a Python list
|
||||
|
||||
|
||||
def p_varlist(p):
|
||||
'''varlist : varlist COMMA variable
|
||||
| variable'''
|
||||
if len(p) > 2:
|
||||
p[0] = p[1]
|
||||
p[0].append(p[3])
|
||||
else:
|
||||
p[0] = [p[1]]
|
||||
|
||||
|
||||
# Builds a list of numbers as a Python list
|
||||
|
||||
def p_numlist(p):
|
||||
'''numlist : numlist COMMA number
|
||||
| number'''
|
||||
|
||||
if len(p) > 2:
|
||||
p[0] = p[1]
|
||||
p[0].append(p[3])
|
||||
else:
|
||||
p[0] = [p[1]]
|
||||
|
||||
# A number. May be an integer or a float
|
||||
|
||||
|
||||
def p_number(p):
|
||||
'''number : INTEGER
|
||||
| FLOAT'''
|
||||
p[0] = eval(p[1])
|
||||
|
||||
# A signed number.
|
||||
|
||||
|
||||
def p_number_signed(p):
|
||||
'''number : MINUS INTEGER
|
||||
| MINUS FLOAT'''
|
||||
p[0] = eval("-" + p[2])
|
||||
|
||||
# List of targets for a print statement
|
||||
# Returns a list of tuples (label,expr)
|
||||
|
||||
|
||||
def p_plist(p):
|
||||
'''plist : plist COMMA pitem
|
||||
| pitem'''
|
||||
if len(p) > 3:
|
||||
p[0] = p[1]
|
||||
p[0].append(p[3])
|
||||
else:
|
||||
p[0] = [p[1]]
|
||||
|
||||
|
||||
def p_item_string(p):
|
||||
'''pitem : STRING'''
|
||||
p[0] = (p[1][1:-1], None)
|
||||
|
||||
|
||||
def p_item_string_expr(p):
|
||||
'''pitem : STRING expr'''
|
||||
p[0] = (p[1][1:-1], p[2])
|
||||
|
||||
|
||||
def p_item_expr(p):
|
||||
'''pitem : expr'''
|
||||
p[0] = ("", p[1])
|
||||
|
||||
# Empty
|
||||
|
||||
|
||||
def p_empty(p):
|
||||
'''empty : '''
|
||||
|
||||
# Catastrophic error handler
|
||||
|
||||
|
||||
def p_error(p):
|
||||
if not p:
|
||||
print("SYNTAX ERROR AT EOF")
|
||||
|
||||
bparser = yacc.yacc()
|
||||
|
||||
|
||||
def parse(data, debug=0):
|
||||
bparser.error = 0
|
||||
p = bparser.parse(data, debug=debug)
|
||||
if bparser.error:
|
||||
return None
|
||||
return p
|
||||
|
|
@ -0,0 +1,14 @@
|
|||
5 DIM A(50,15)
|
||||
10 FOR I = 1 TO 50
|
||||
20 FOR J = 1 TO 15
|
||||
30 LET A(I,J) = I + J
|
||||
35 REM PRINT I,J, A(I,J)
|
||||
40 NEXT J
|
||||
50 NEXT I
|
||||
100 FOR I = 1 TO 50
|
||||
110 FOR J = 1 TO 15
|
||||
120 PRINT A(I,J),
|
||||
130 NEXT J
|
||||
140 PRINT
|
||||
150 NEXT I
|
||||
999 END
|
||||
|
|
@ -0,0 +1,5 @@
|
|||
10 DEF FDX(X) = 2*X
|
||||
20 FOR I = 0 TO 100
|
||||
30 PRINT FDX(I)
|
||||
40 NEXT I
|
||||
50 END
|
||||
|
|
@ -0,0 +1,22 @@
|
|||
10 PRINT "A","B","C","GCD"
|
||||
20 READ A,B,C
|
||||
30 LET X = A
|
||||
40 LET Y = B
|
||||
50 GOSUB 200
|
||||
60 LET X = G
|
||||
70 LET Y = C
|
||||
80 GOSUB 200
|
||||
90 PRINT A, B, C, G
|
||||
100 GOTO 20
|
||||
110 DATA 60, 90, 120
|
||||
120 DATA 38456, 64872, 98765
|
||||
130 DATA 32, 384, 72
|
||||
200 LET Q = INT(X/Y)
|
||||
210 LET R = X - Q*Y
|
||||
220 IF R = 0 THEN 300
|
||||
230 LET X = Y
|
||||
240 LET Y = R
|
||||
250 GOTO 200
|
||||
300 LET G = Y
|
||||
310 RETURN
|
||||
999 END
|
||||
|
|
@ -0,0 +1,13 @@
|
|||
100 LET X = 3
|
||||
110 GOSUB 400
|
||||
120 PRINT U, V, W
|
||||
200 LET X = 5
|
||||
210 GOSUB 400
|
||||
220 LET Z = U + 2*V + 3*W
|
||||
230 PRINT Z
|
||||
240 GOTO 999
|
||||
400 LET U = X*X
|
||||
410 LET V = X*X*X
|
||||
420 LET W = X*X*X*X + X*X*X + X*X + X
|
||||
430 RETURN
|
||||
999 END
|
||||
|
|
@ -0,0 +1,4 @@
|
|||
5 REM HELLO WORLD PROGAM
|
||||
10 PRINT "HELLO WORLD"
|
||||
99 END
|
||||
|
||||
|
|
@ -0,0 +1,17 @@
|
|||
1 REM ::: SOLVE A SYSTEM OF LINEAR EQUATIONS
|
||||
2 REM ::: A1*X1 + A2*X2 = B1
|
||||
3 REM ::: A3*X1 + A4*X2 = B2
|
||||
4 REM --------------------------------------
|
||||
10 READ A1, A2, A3, A4
|
||||
15 LET D = A1 * A4 - A3 * A2
|
||||
20 IF D = 0 THEN 65
|
||||
30 READ B1, B2
|
||||
37 LET X1 = (B1*A4 - B2*A2) / D
|
||||
42 LET X2 = (A1*B2 - A3*B1) / D
|
||||
55 PRINT X1, X2
|
||||
60 GOTO 30
|
||||
65 PRINT "NO UNIQUE SOLUTION"
|
||||
70 DATA 1, 2, 4
|
||||
80 DATA 2, -7, 5
|
||||
85 DATA 1, 3, 4, -7
|
||||
90 END
|
||||
|
|
@ -0,0 +1,12 @@
|
|||
5 PRINT "X VALUE", "SINE", "RESOLUTION"
|
||||
10 READ D
|
||||
20 LET M = -1
|
||||
30 FOR X = 0 TO 3 STEP D
|
||||
40 IF SIN(X) <= M THEN 80
|
||||
50 LET X0 = X
|
||||
60 LET M = SIN(X)
|
||||
80 NEXT X
|
||||
85 PRINT X0, M, D
|
||||
90 GOTO 10
|
||||
100 DATA .1, .01, .001
|
||||
110 END
|
||||
|
|
@ -0,0 +1,13 @@
|
|||
5 PRINT "THIS PROGRAM COMPUTES AND PRINTS THE NTH POWERS"
|
||||
6 PRINT "OF THE NUMBERS LESS THAN OR EQUAL TO N FOR VARIOUS"
|
||||
7 PRINT "N FROM 1 THROUGH 7"
|
||||
8 PRINT
|
||||
10 FOR N = 1 TO 7
|
||||
15 PRINT "N = "N
|
||||
20 FOR I = 1 TO N
|
||||
30 PRINT I^N,
|
||||
40 NEXT I
|
||||
50 PRINT
|
||||
60 PRINT
|
||||
70 NEXT N
|
||||
80 END
|
||||
|
|
@ -0,0 +1,4 @@
|
|||
10 FOR I = 1 TO 20
|
||||
20 PRINT INT(10*RND(0))
|
||||
30 NEXT I
|
||||
40 END
|
||||
|
|
@ -0,0 +1,20 @@
|
|||
10 FOR I = 1 TO 3
|
||||
20 READ P(I)
|
||||
30 NEXT I
|
||||
40 FOR I = 1 TO 3
|
||||
50 FOR J = 1 TO 5
|
||||
60 READ S(I,J)
|
||||
70 NEXT J
|
||||
80 NEXT I
|
||||
90 FOR J = 1 TO 5
|
||||
100 LET S = 0
|
||||
110 FOR I = 1 TO 3
|
||||
120 LET S = S + P(I) * S(I,J)
|
||||
130 NEXT I
|
||||
140 PRINT "TOTAL SALES FOR SALESMAN"J, "$"S
|
||||
150 NEXT J
|
||||
200 DATA 1.25, 4.30, 2.50
|
||||
210 DATA 40, 20, 37, 29, 42
|
||||
220 DATA 10, 16, 3, 21, 8
|
||||
230 DATA 35, 47, 29, 16, 33
|
||||
300 END
|
||||
|
|
@ -0,0 +1,18 @@
|
|||
1 REM :: THIS PROGRAM COMPUTES HOW MANY TIMES YOU HAVE TO FOLD
|
||||
2 REM :: A PIECE OF PAPER SO THAT IT IS TALLER THAN THE
|
||||
3 REM :: SEARS TOWER.
|
||||
4 REM :: S = HEIGHT OF TOWER (METERS)
|
||||
5 REM :: T = THICKNESS OF PAPER (MILLIMETERS)
|
||||
10 LET S = 442
|
||||
20 LET T = 0.1
|
||||
30 REM CONVERT T TO METERS
|
||||
40 LET T = T * .001
|
||||
50 LET F = 1
|
||||
60 LET H = T
|
||||
100 IF H > S THEN 200
|
||||
120 LET H = 2 * H
|
||||
125 LET F = F + 1
|
||||
130 GOTO 100
|
||||
200 PRINT "NUMBER OF FOLDS ="F
|
||||
220 PRINT "FINAL HEIGHT ="H
|
||||
999 END
|
||||
|
|
@ -0,0 +1,5 @@
|
|||
10 LET X = 0
|
||||
20 LET X = X + 1
|
||||
30 PRINT X, SQR(X)
|
||||
40 IF X < 100 THEN 20
|
||||
50 END
|
||||
|
|
@ -0,0 +1,4 @@
|
|||
10 FOR X = 1 TO 100
|
||||
20 PRINT X, SQR(X)
|
||||
30 NEXT X
|
||||
40 END
|
||||
|
|
@ -0,0 +1,777 @@
|
|||
# GardenSnake - a parser generator demonstration program
|
||||
#
|
||||
# This implements a modified version of a subset of Python:
|
||||
# - only 'def', 'return' and 'if' statements
|
||||
# - 'if' only has 'then' clause (no elif nor else)
|
||||
# - single-quoted strings only, content in raw format
|
||||
# - numbers are decimal.Decimal instances (not integers or floats)
|
||||
# - no print statment; use the built-in 'print' function
|
||||
# - only < > == + - / * implemented (and unary + -)
|
||||
# - assignment and tuple assignment work
|
||||
# - no generators of any sort
|
||||
# - no ... well, no quite a lot
|
||||
|
||||
# Why? I'm thinking about a new indentation-based configuration
|
||||
# language for a project and wanted to figure out how to do it. Once
|
||||
# I got that working I needed a way to test it out. My original AST
|
||||
# was dumb so I decided to target Python's AST and compile it into
|
||||
# Python code. Plus, it's pretty cool that it only took a day or so
|
||||
# from sitting down with Ply to having working code.
|
||||
|
||||
# This uses David Beazley's Ply from http://www.dabeaz.com/ply/
|
||||
|
||||
# This work is hereby released into the Public Domain. To view a copy of
|
||||
# the public domain dedication, visit
|
||||
# http://creativecommons.org/licenses/publicdomain/ or send a letter to
|
||||
# Creative Commons, 543 Howard Street, 5th Floor, San Francisco,
|
||||
# California, 94105, USA.
|
||||
#
|
||||
# Portions of this work are derived from Python's Grammar definition
|
||||
# and may be covered under the Python copyright and license
|
||||
#
|
||||
# Andrew Dalke / Dalke Scientific Software, LLC
|
||||
# 30 August 2006 / Cape Town, South Africa
|
||||
|
||||
# Changelog:
|
||||
# 30 August - added link to CC license; removed the "swapcase" encoding
|
||||
|
||||
# Modifications for inclusion in PLY distribution
|
||||
import sys
|
||||
sys.path.insert(0, "../..")
|
||||
from ply import *
|
||||
|
||||
##### Lexer ######
|
||||
#import lex
|
||||
import decimal
|
||||
|
||||
tokens = (
|
||||
'DEF',
|
||||
'IF',
|
||||
'NAME',
|
||||
'NUMBER', # Python decimals
|
||||
'STRING', # single quoted strings only; syntax of raw strings
|
||||
'LPAR',
|
||||
'RPAR',
|
||||
'COLON',
|
||||
'EQ',
|
||||
'ASSIGN',
|
||||
'LT',
|
||||
'GT',
|
||||
'PLUS',
|
||||
'MINUS',
|
||||
'MULT',
|
||||
'DIV',
|
||||
'RETURN',
|
||||
'WS',
|
||||
'NEWLINE',
|
||||
'COMMA',
|
||||
'SEMICOLON',
|
||||
'INDENT',
|
||||
'DEDENT',
|
||||
'ENDMARKER',
|
||||
)
|
||||
|
||||
#t_NUMBER = r'\d+'
|
||||
# taken from decmial.py but without the leading sign
|
||||
|
||||
|
||||
def t_NUMBER(t):
|
||||
r"""(\d+(\.\d*)?|\.\d+)([eE][-+]? \d+)?"""
|
||||
t.value = decimal.Decimal(t.value)
|
||||
return t
|
||||
|
||||
|
||||
def t_STRING(t):
|
||||
r"'([^\\']+|\\'|\\\\)*'" # I think this is right ...
|
||||
t.value = t.value[1:-1].decode("string-escape") # .swapcase() # for fun
|
||||
return t
|
||||
|
||||
t_COLON = r':'
|
||||
t_EQ = r'=='
|
||||
t_ASSIGN = r'='
|
||||
t_LT = r'<'
|
||||
t_GT = r'>'
|
||||
t_PLUS = r'\+'
|
||||
t_MINUS = r'-'
|
||||
t_MULT = r'\*'
|
||||
t_DIV = r'/'
|
||||
t_COMMA = r','
|
||||
t_SEMICOLON = r';'
|
||||
|
||||
# Ply nicely documented how to do this.
|
||||
|
||||
RESERVED = {
|
||||
"def": "DEF",
|
||||
"if": "IF",
|
||||
"return": "RETURN",
|
||||
}
|
||||
|
||||
|
||||
def t_NAME(t):
|
||||
r'[a-zA-Z_][a-zA-Z0-9_]*'
|
||||
t.type = RESERVED.get(t.value, "NAME")
|
||||
return t
|
||||
|
||||
# Putting this before t_WS let it consume lines with only comments in
|
||||
# them so the latter code never sees the WS part. Not consuming the
|
||||
# newline. Needed for "if 1: #comment"
|
||||
|
||||
|
||||
def t_comment(t):
|
||||
r"[ ]*\043[^\n]*" # \043 is '#'
|
||||
pass
|
||||
|
||||
|
||||
# Whitespace
|
||||
def t_WS(t):
|
||||
r' [ ]+ '
|
||||
if t.lexer.at_line_start and t.lexer.paren_count == 0:
|
||||
return t
|
||||
|
||||
# Don't generate newline tokens when inside of parenthesis, eg
|
||||
# a = (1,
|
||||
# 2, 3)
|
||||
|
||||
|
||||
def t_newline(t):
|
||||
r'\n+'
|
||||
t.lexer.lineno += len(t.value)
|
||||
t.type = "NEWLINE"
|
||||
if t.lexer.paren_count == 0:
|
||||
return t
|
||||
|
||||
|
||||
def t_LPAR(t):
|
||||
r'\('
|
||||
t.lexer.paren_count += 1
|
||||
return t
|
||||
|
||||
|
||||
def t_RPAR(t):
|
||||
r'\)'
|
||||
# check for underflow? should be the job of the parser
|
||||
t.lexer.paren_count -= 1
|
||||
return t
|
||||
|
||||
|
||||
def t_error(t):
|
||||
raise SyntaxError("Unknown symbol %r" % (t.value[0],))
|
||||
print "Skipping", repr(t.value[0])
|
||||
t.lexer.skip(1)
|
||||
|
||||
# I implemented INDENT / DEDENT generation as a post-processing filter
|
||||
|
||||
# The original lex token stream contains WS and NEWLINE characters.
|
||||
# WS will only occur before any other tokens on a line.
|
||||
|
||||
# I have three filters. One tags tokens by adding two attributes.
|
||||
# "must_indent" is True if the token must be indented from the
|
||||
# previous code. The other is "at_line_start" which is True for WS
|
||||
# and the first non-WS/non-NEWLINE on a line. It flags the check so
|
||||
# see if the new line has changed indication level.
|
||||
|
||||
# Python's syntax has three INDENT states
|
||||
# 0) no colon hence no need to indent
|
||||
# 1) "if 1: go()" - simple statements have a COLON but no need for an indent
|
||||
# 2) "if 1:\n go()" - complex statements have a COLON NEWLINE and must indent
|
||||
NO_INDENT = 0
|
||||
MAY_INDENT = 1
|
||||
MUST_INDENT = 2
|
||||
|
||||
# only care about whitespace at the start of a line
|
||||
|
||||
|
||||
def track_tokens_filter(lexer, tokens):
|
||||
lexer.at_line_start = at_line_start = True
|
||||
indent = NO_INDENT
|
||||
saw_colon = False
|
||||
for token in tokens:
|
||||
token.at_line_start = at_line_start
|
||||
|
||||
if token.type == "COLON":
|
||||
at_line_start = False
|
||||
indent = MAY_INDENT
|
||||
token.must_indent = False
|
||||
|
||||
elif token.type == "NEWLINE":
|
||||
at_line_start = True
|
||||
if indent == MAY_INDENT:
|
||||
indent = MUST_INDENT
|
||||
token.must_indent = False
|
||||
|
||||
elif token.type == "WS":
|
||||
assert token.at_line_start == True
|
||||
at_line_start = True
|
||||
token.must_indent = False
|
||||
|
||||
else:
|
||||
# A real token; only indent after COLON NEWLINE
|
||||
if indent == MUST_INDENT:
|
||||
token.must_indent = True
|
||||
else:
|
||||
token.must_indent = False
|
||||
at_line_start = False
|
||||
indent = NO_INDENT
|
||||
|
||||
yield token
|
||||
lexer.at_line_start = at_line_start
|
||||
|
||||
|
||||
def _new_token(type, lineno):
|
||||
tok = lex.LexToken()
|
||||
tok.type = type
|
||||
tok.value = None
|
||||
tok.lineno = lineno
|
||||
return tok
|
||||
|
||||
# Synthesize a DEDENT tag
|
||||
|
||||
|
||||
def DEDENT(lineno):
|
||||
return _new_token("DEDENT", lineno)
|
||||
|
||||
# Synthesize an INDENT tag
|
||||
|
||||
|
||||
def INDENT(lineno):
|
||||
return _new_token("INDENT", lineno)
|
||||
|
||||
|
||||
# Track the indentation level and emit the right INDENT / DEDENT events.
|
||||
def indentation_filter(tokens):
|
||||
# A stack of indentation levels; will never pop item 0
|
||||
levels = [0]
|
||||
token = None
|
||||
depth = 0
|
||||
prev_was_ws = False
|
||||
for token in tokens:
|
||||
# if 1:
|
||||
# print "Process", token,
|
||||
# if token.at_line_start:
|
||||
# print "at_line_start",
|
||||
# if token.must_indent:
|
||||
# print "must_indent",
|
||||
# print
|
||||
|
||||
# WS only occurs at the start of the line
|
||||
# There may be WS followed by NEWLINE so
|
||||
# only track the depth here. Don't indent/dedent
|
||||
# until there's something real.
|
||||
if token.type == "WS":
|
||||
assert depth == 0
|
||||
depth = len(token.value)
|
||||
prev_was_ws = True
|
||||
# WS tokens are never passed to the parser
|
||||
continue
|
||||
|
||||
if token.type == "NEWLINE":
|
||||
depth = 0
|
||||
if prev_was_ws or token.at_line_start:
|
||||
# ignore blank lines
|
||||
continue
|
||||
# pass the other cases on through
|
||||
yield token
|
||||
continue
|
||||
|
||||
# then it must be a real token (not WS, not NEWLINE)
|
||||
# which can affect the indentation level
|
||||
|
||||
prev_was_ws = False
|
||||
if token.must_indent:
|
||||
# The current depth must be larger than the previous level
|
||||
if not (depth > levels[-1]):
|
||||
raise IndentationError("expected an indented block")
|
||||
|
||||
levels.append(depth)
|
||||
yield INDENT(token.lineno)
|
||||
|
||||
elif token.at_line_start:
|
||||
# Must be on the same level or one of the previous levels
|
||||
if depth == levels[-1]:
|
||||
# At the same level
|
||||
pass
|
||||
elif depth > levels[-1]:
|
||||
raise IndentationError(
|
||||
"indentation increase but not in new block")
|
||||
else:
|
||||
# Back up; but only if it matches a previous level
|
||||
try:
|
||||
i = levels.index(depth)
|
||||
except ValueError:
|
||||
raise IndentationError("inconsistent indentation")
|
||||
for _ in range(i + 1, len(levels)):
|
||||
yield DEDENT(token.lineno)
|
||||
levels.pop()
|
||||
|
||||
yield token
|
||||
|
||||
### Finished processing ###
|
||||
|
||||
# Must dedent any remaining levels
|
||||
if len(levels) > 1:
|
||||
assert token is not None
|
||||
for _ in range(1, len(levels)):
|
||||
yield DEDENT(token.lineno)
|
||||
|
||||
|
||||
# The top-level filter adds an ENDMARKER, if requested.
|
||||
# Python's grammar uses it.
|
||||
def filter(lexer, add_endmarker=True):
|
||||
token = None
|
||||
tokens = iter(lexer.token, None)
|
||||
tokens = track_tokens_filter(lexer, tokens)
|
||||
for token in indentation_filter(tokens):
|
||||
yield token
|
||||
|
||||
if add_endmarker:
|
||||
lineno = 1
|
||||
if token is not None:
|
||||
lineno = token.lineno
|
||||
yield _new_token("ENDMARKER", lineno)
|
||||
|
||||
# Combine Ply and my filters into a new lexer
|
||||
|
||||
|
||||
class IndentLexer(object):
|
||||
|
||||
def __init__(self, debug=0, optimize=0, lextab='lextab', reflags=0):
|
||||
self.lexer = lex.lex(debug=debug, optimize=optimize,
|
||||
lextab=lextab, reflags=reflags)
|
||||
self.token_stream = None
|
||||
|
||||
def input(self, s, add_endmarker=True):
|
||||
self.lexer.paren_count = 0
|
||||
self.lexer.input(s)
|
||||
self.token_stream = filter(self.lexer, add_endmarker)
|
||||
|
||||
def token(self):
|
||||
try:
|
||||
return self.token_stream.next()
|
||||
except StopIteration:
|
||||
return None
|
||||
|
||||
########## Parser (tokens -> AST) ######
|
||||
|
||||
# also part of Ply
|
||||
#import yacc
|
||||
|
||||
# I use the Python AST
|
||||
from compiler import ast
|
||||
|
||||
# Helper function
|
||||
|
||||
|
||||
def Assign(left, right):
|
||||
names = []
|
||||
if isinstance(left, ast.Name):
|
||||
# Single assignment on left
|
||||
return ast.Assign([ast.AssName(left.name, 'OP_ASSIGN')], right)
|
||||
elif isinstance(left, ast.Tuple):
|
||||
# List of things - make sure they are Name nodes
|
||||
names = []
|
||||
for child in left.getChildren():
|
||||
if not isinstance(child, ast.Name):
|
||||
raise SyntaxError("that assignment not supported")
|
||||
names.append(child.name)
|
||||
ass_list = [ast.AssName(name, 'OP_ASSIGN') for name in names]
|
||||
return ast.Assign([ast.AssTuple(ass_list)], right)
|
||||
else:
|
||||
raise SyntaxError("Can't do that yet")
|
||||
|
||||
|
||||
# The grammar comments come from Python's Grammar/Grammar file
|
||||
|
||||
# NB: compound_stmt in single_input is followed by extra NEWLINE!
|
||||
# file_input: (NEWLINE | stmt)* ENDMARKER
|
||||
def p_file_input_end(p):
|
||||
"""file_input_end : file_input ENDMARKER"""
|
||||
p[0] = ast.Stmt(p[1])
|
||||
|
||||
|
||||
def p_file_input(p):
|
||||
"""file_input : file_input NEWLINE
|
||||
| file_input stmt
|
||||
| NEWLINE
|
||||
| stmt"""
|
||||
if isinstance(p[len(p) - 1], basestring):
|
||||
if len(p) == 3:
|
||||
p[0] = p[1]
|
||||
else:
|
||||
p[0] = [] # p == 2 --> only a blank line
|
||||
else:
|
||||
if len(p) == 3:
|
||||
p[0] = p[1] + p[2]
|
||||
else:
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
# funcdef: [decorators] 'def' NAME parameters ':' suite
|
||||
# ignoring decorators
|
||||
def p_funcdef(p):
|
||||
"funcdef : DEF NAME parameters COLON suite"
|
||||
p[0] = ast.Function(None, p[2], tuple(p[3]), (), 0, None, p[5])
|
||||
|
||||
# parameters: '(' [varargslist] ')'
|
||||
|
||||
|
||||
def p_parameters(p):
|
||||
"""parameters : LPAR RPAR
|
||||
| LPAR varargslist RPAR"""
|
||||
if len(p) == 3:
|
||||
p[0] = []
|
||||
else:
|
||||
p[0] = p[2]
|
||||
|
||||
|
||||
# varargslist: (fpdef ['=' test] ',')* ('*' NAME [',' '**' NAME] | '**' NAME) |
|
||||
# highly simplified
|
||||
def p_varargslist(p):
|
||||
"""varargslist : varargslist COMMA NAME
|
||||
| NAME"""
|
||||
if len(p) == 4:
|
||||
p[0] = p[1] + p[3]
|
||||
else:
|
||||
p[0] = [p[1]]
|
||||
|
||||
# stmt: simple_stmt | compound_stmt
|
||||
|
||||
|
||||
def p_stmt_simple(p):
|
||||
"""stmt : simple_stmt"""
|
||||
# simple_stmt is a list
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
def p_stmt_compound(p):
|
||||
"""stmt : compound_stmt"""
|
||||
p[0] = [p[1]]
|
||||
|
||||
# simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
|
||||
|
||||
|
||||
def p_simple_stmt(p):
|
||||
"""simple_stmt : small_stmts NEWLINE
|
||||
| small_stmts SEMICOLON NEWLINE"""
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
def p_small_stmts(p):
|
||||
"""small_stmts : small_stmts SEMICOLON small_stmt
|
||||
| small_stmt"""
|
||||
if len(p) == 4:
|
||||
p[0] = p[1] + [p[3]]
|
||||
else:
|
||||
p[0] = [p[1]]
|
||||
|
||||
# small_stmt: expr_stmt | print_stmt | del_stmt | pass_stmt | flow_stmt |
|
||||
# import_stmt | global_stmt | exec_stmt | assert_stmt
|
||||
|
||||
|
||||
def p_small_stmt(p):
|
||||
"""small_stmt : flow_stmt
|
||||
| expr_stmt"""
|
||||
p[0] = p[1]
|
||||
|
||||
# expr_stmt: testlist (augassign (yield_expr|testlist) |
|
||||
# ('=' (yield_expr|testlist))*)
|
||||
# augassign: ('+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' |
|
||||
# '<<=' | '>>=' | '**=' | '//=')
|
||||
|
||||
|
||||
def p_expr_stmt(p):
|
||||
"""expr_stmt : testlist ASSIGN testlist
|
||||
| testlist """
|
||||
if len(p) == 2:
|
||||
# a list of expressions
|
||||
p[0] = ast.Discard(p[1])
|
||||
else:
|
||||
p[0] = Assign(p[1], p[3])
|
||||
|
||||
|
||||
def p_flow_stmt(p):
|
||||
"flow_stmt : return_stmt"
|
||||
p[0] = p[1]
|
||||
|
||||
# return_stmt: 'return' [testlist]
|
||||
|
||||
|
||||
def p_return_stmt(p):
|
||||
"return_stmt : RETURN testlist"
|
||||
p[0] = ast.Return(p[2])
|
||||
|
||||
|
||||
def p_compound_stmt(p):
|
||||
"""compound_stmt : if_stmt
|
||||
| funcdef"""
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
def p_if_stmt(p):
|
||||
'if_stmt : IF test COLON suite'
|
||||
p[0] = ast.If([(p[2], p[4])], None)
|
||||
|
||||
|
||||
def p_suite(p):
|
||||
"""suite : simple_stmt
|
||||
| NEWLINE INDENT stmts DEDENT"""
|
||||
if len(p) == 2:
|
||||
p[0] = ast.Stmt(p[1])
|
||||
else:
|
||||
p[0] = ast.Stmt(p[3])
|
||||
|
||||
|
||||
def p_stmts(p):
|
||||
"""stmts : stmts stmt
|
||||
| stmt"""
|
||||
if len(p) == 3:
|
||||
p[0] = p[1] + p[2]
|
||||
else:
|
||||
p[0] = p[1]
|
||||
|
||||
# No using Python's approach because Ply supports precedence
|
||||
|
||||
# comparison: expr (comp_op expr)*
|
||||
# arith_expr: term (('+'|'-') term)*
|
||||
# term: factor (('*'|'/'|'%'|'//') factor)*
|
||||
# factor: ('+'|'-'|'~') factor | power
|
||||
# comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
|
||||
|
||||
|
||||
def make_lt_compare((left, right)):
|
||||
return ast.Compare(left, [('<', right), ])
|
||||
|
||||
|
||||
def make_gt_compare((left, right)):
|
||||
return ast.Compare(left, [('>', right), ])
|
||||
|
||||
|
||||
def make_eq_compare((left, right)):
|
||||
return ast.Compare(left, [('==', right), ])
|
||||
|
||||
|
||||
binary_ops = {
|
||||
"+": ast.Add,
|
||||
"-": ast.Sub,
|
||||
"*": ast.Mul,
|
||||
"/": ast.Div,
|
||||
"<": make_lt_compare,
|
||||
">": make_gt_compare,
|
||||
"==": make_eq_compare,
|
||||
}
|
||||
unary_ops = {
|
||||
"+": ast.UnaryAdd,
|
||||
"-": ast.UnarySub,
|
||||
}
|
||||
precedence = (
|
||||
("left", "EQ", "GT", "LT"),
|
||||
("left", "PLUS", "MINUS"),
|
||||
("left", "MULT", "DIV"),
|
||||
)
|
||||
|
||||
|
||||
def p_comparison(p):
|
||||
"""comparison : comparison PLUS comparison
|
||||
| comparison MINUS comparison
|
||||
| comparison MULT comparison
|
||||
| comparison DIV comparison
|
||||
| comparison LT comparison
|
||||
| comparison EQ comparison
|
||||
| comparison GT comparison
|
||||
| PLUS comparison
|
||||
| MINUS comparison
|
||||
| power"""
|
||||
if len(p) == 4:
|
||||
p[0] = binary_ops[p[2]]((p[1], p[3]))
|
||||
elif len(p) == 3:
|
||||
p[0] = unary_ops[p[1]](p[2])
|
||||
else:
|
||||
p[0] = p[1]
|
||||
|
||||
# power: atom trailer* ['**' factor]
|
||||
# trailers enables function calls. I only allow one level of calls
|
||||
# so this is 'trailer'
|
||||
|
||||
|
||||
def p_power(p):
|
||||
"""power : atom
|
||||
| atom trailer"""
|
||||
if len(p) == 2:
|
||||
p[0] = p[1]
|
||||
else:
|
||||
if p[2][0] == "CALL":
|
||||
p[0] = ast.CallFunc(p[1], p[2][1], None, None)
|
||||
else:
|
||||
raise AssertionError("not implemented")
|
||||
|
||||
|
||||
def p_atom_name(p):
|
||||
"""atom : NAME"""
|
||||
p[0] = ast.Name(p[1])
|
||||
|
||||
|
||||
def p_atom_number(p):
|
||||
"""atom : NUMBER
|
||||
| STRING"""
|
||||
p[0] = ast.Const(p[1])
|
||||
|
||||
|
||||
def p_atom_tuple(p):
|
||||
"""atom : LPAR testlist RPAR"""
|
||||
p[0] = p[2]
|
||||
|
||||
# trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
|
||||
|
||||
|
||||
def p_trailer(p):
|
||||
"trailer : LPAR arglist RPAR"
|
||||
p[0] = ("CALL", p[2])
|
||||
|
||||
# testlist: test (',' test)* [',']
|
||||
# Contains shift/reduce error
|
||||
|
||||
|
||||
def p_testlist(p):
|
||||
"""testlist : testlist_multi COMMA
|
||||
| testlist_multi """
|
||||
if len(p) == 2:
|
||||
p[0] = p[1]
|
||||
else:
|
||||
# May need to promote singleton to tuple
|
||||
if isinstance(p[1], list):
|
||||
p[0] = p[1]
|
||||
else:
|
||||
p[0] = [p[1]]
|
||||
# Convert into a tuple?
|
||||
if isinstance(p[0], list):
|
||||
p[0] = ast.Tuple(p[0])
|
||||
|
||||
|
||||
def p_testlist_multi(p):
|
||||
"""testlist_multi : testlist_multi COMMA test
|
||||
| test"""
|
||||
if len(p) == 2:
|
||||
# singleton
|
||||
p[0] = p[1]
|
||||
else:
|
||||
if isinstance(p[1], list):
|
||||
p[0] = p[1] + [p[3]]
|
||||
else:
|
||||
# singleton -> tuple
|
||||
p[0] = [p[1], p[3]]
|
||||
|
||||
|
||||
# test: or_test ['if' or_test 'else' test] | lambdef
|
||||
# as I don't support 'and', 'or', and 'not' this works down to 'comparison'
|
||||
def p_test(p):
|
||||
"test : comparison"
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
# arglist: (argument ',')* (argument [',']| '*' test [',' '**' test] | '**' test)
|
||||
# XXX INCOMPLETE: this doesn't allow the trailing comma
|
||||
def p_arglist(p):
|
||||
"""arglist : arglist COMMA argument
|
||||
| argument"""
|
||||
if len(p) == 4:
|
||||
p[0] = p[1] + [p[3]]
|
||||
else:
|
||||
p[0] = [p[1]]
|
||||
|
||||
# argument: test [gen_for] | test '=' test # Really [keyword '='] test
|
||||
|
||||
|
||||
def p_argument(p):
|
||||
"argument : test"
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
def p_error(p):
|
||||
# print "Error!", repr(p)
|
||||
raise SyntaxError(p)
|
||||
|
||||
|
||||
class GardenSnakeParser(object):
|
||||
|
||||
def __init__(self, lexer=None):
|
||||
if lexer is None:
|
||||
lexer = IndentLexer()
|
||||
self.lexer = lexer
|
||||
self.parser = yacc.yacc(start="file_input_end")
|
||||
|
||||
def parse(self, code):
|
||||
self.lexer.input(code)
|
||||
result = self.parser.parse(lexer=self.lexer)
|
||||
return ast.Module(None, result)
|
||||
|
||||
|
||||
###### Code generation ######
|
||||
|
||||
from compiler import misc, syntax, pycodegen
|
||||
|
||||
|
||||
class GardenSnakeCompiler(object):
|
||||
|
||||
def __init__(self):
|
||||
self.parser = GardenSnakeParser()
|
||||
|
||||
def compile(self, code, filename="<string>"):
|
||||
tree = self.parser.parse(code)
|
||||
# print tree
|
||||
misc.set_filename(filename, tree)
|
||||
syntax.check(tree)
|
||||
gen = pycodegen.ModuleCodeGenerator(tree)
|
||||
code = gen.getCode()
|
||||
return code
|
||||
|
||||
####### Test code #######
|
||||
|
||||
compile = GardenSnakeCompiler().compile
|
||||
|
||||
code = r"""
|
||||
|
||||
print('LET\'S TRY THIS \\OUT')
|
||||
|
||||
#Comment here
|
||||
def x(a):
|
||||
print('called with',a)
|
||||
if a == 1:
|
||||
return 2
|
||||
if a*2 > 10: return 999 / 4
|
||||
# Another comment here
|
||||
|
||||
return a+2*3
|
||||
|
||||
ints = (1, 2,
|
||||
3, 4,
|
||||
5)
|
||||
print('mutiline-expression', ints)
|
||||
|
||||
t = 4+1/3*2+6*(9-5+1)
|
||||
print('predence test; should be 34+2/3:', t, t==(34+2/3))
|
||||
|
||||
print('numbers', 1,2,3,4,5)
|
||||
if 1:
|
||||
8
|
||||
a=9
|
||||
print(x(a))
|
||||
|
||||
print(x(1))
|
||||
print(x(2))
|
||||
print(x(8),'3')
|
||||
print('this is decimal', 1/5)
|
||||
print('BIG DECIMAL', 1.234567891234567e12345)
|
||||
|
||||
"""
|
||||
|
||||
# Set up the GardenSnake run-time environment
|
||||
|
||||
|
||||
def print_(*args):
|
||||
print "-->", " ".join(map(str, args))
|
||||
|
||||
globals()["print"] = print_
|
||||
|
||||
compiled_code = compile(code)
|
||||
|
||||
exec compiled_code in globals()
|
||||
print "Done"
|
||||
|
|
@ -0,0 +1,5 @@
|
|||
This example is Andrew Dalke's GardenSnake language. It shows how to process an
|
||||
indentation-like language like Python. Further details can be found here:
|
||||
|
||||
http://dalkescientific.com/writings/diary/archive/2006/08/30/gardensnake_language.html
|
||||
|
||||
10
components/script/dom/bindings/codegen/ply/example/README
Normal file
10
components/script/dom/bindings/codegen/ply/example/README
Normal file
|
|
@ -0,0 +1,10 @@
|
|||
Simple examples:
|
||||
calc - Simple calculator
|
||||
classcalc - Simple calculate defined as a class
|
||||
|
||||
Complex examples
|
||||
ansic - ANSI C grammar from K&R
|
||||
BASIC - A small BASIC interpreter
|
||||
GardenSnake - A simple python-like language
|
||||
yply - Converts Unix yacc files to PLY programs.
|
||||
|
||||
|
|
@ -0,0 +1,2 @@
|
|||
This example is incomplete. Was going to specify an ANSI C parser.
|
||||
This is part of it.
|
||||
168
components/script/dom/bindings/codegen/ply/example/ansic/clex.py
Normal file
168
components/script/dom/bindings/codegen/ply/example/ansic/clex.py
Normal file
|
|
@ -0,0 +1,168 @@
|
|||
# ----------------------------------------------------------------------
|
||||
# clex.py
|
||||
#
|
||||
# A lexer for ANSI C.
|
||||
# ----------------------------------------------------------------------
|
||||
|
||||
import sys
|
||||
sys.path.insert(0, "../..")
|
||||
|
||||
import ply.lex as lex
|
||||
|
||||
# Reserved words
|
||||
reserved = (
|
||||
'AUTO', 'BREAK', 'CASE', 'CHAR', 'CONST', 'CONTINUE', 'DEFAULT', 'DO', 'DOUBLE',
|
||||
'ELSE', 'ENUM', 'EXTERN', 'FLOAT', 'FOR', 'GOTO', 'IF', 'INT', 'LONG', 'REGISTER',
|
||||
'RETURN', 'SHORT', 'SIGNED', 'SIZEOF', 'STATIC', 'STRUCT', 'SWITCH', 'TYPEDEF',
|
||||
'UNION', 'UNSIGNED', 'VOID', 'VOLATILE', 'WHILE',
|
||||
)
|
||||
|
||||
tokens = reserved + (
|
||||
# Literals (identifier, integer constant, float constant, string constant,
|
||||
# char const)
|
||||
'ID', 'TYPEID', 'ICONST', 'FCONST', 'SCONST', 'CCONST',
|
||||
|
||||
# Operators (+,-,*,/,%,|,&,~,^,<<,>>, ||, &&, !, <, <=, >, >=, ==, !=)
|
||||
'PLUS', 'MINUS', 'TIMES', 'DIVIDE', 'MOD',
|
||||
'OR', 'AND', 'NOT', 'XOR', 'LSHIFT', 'RSHIFT',
|
||||
'LOR', 'LAND', 'LNOT',
|
||||
'LT', 'LE', 'GT', 'GE', 'EQ', 'NE',
|
||||
|
||||
# Assignment (=, *=, /=, %=, +=, -=, <<=, >>=, &=, ^=, |=)
|
||||
'EQUALS', 'TIMESEQUAL', 'DIVEQUAL', 'MODEQUAL', 'PLUSEQUAL', 'MINUSEQUAL',
|
||||
'LSHIFTEQUAL', 'RSHIFTEQUAL', 'ANDEQUAL', 'XOREQUAL', 'OREQUAL',
|
||||
|
||||
# Increment/decrement (++,--)
|
||||
'PLUSPLUS', 'MINUSMINUS',
|
||||
|
||||
# Structure dereference (->)
|
||||
'ARROW',
|
||||
|
||||
# Conditional operator (?)
|
||||
'CONDOP',
|
||||
|
||||
# Delimeters ( ) [ ] { } , . ; :
|
||||
'LPAREN', 'RPAREN',
|
||||
'LBRACKET', 'RBRACKET',
|
||||
'LBRACE', 'RBRACE',
|
||||
'COMMA', 'PERIOD', 'SEMI', 'COLON',
|
||||
|
||||
# Ellipsis (...)
|
||||
'ELLIPSIS',
|
||||
)
|
||||
|
||||
# Completely ignored characters
|
||||
t_ignore = ' \t\x0c'
|
||||
|
||||
# Newlines
|
||||
|
||||
|
||||
def t_NEWLINE(t):
|
||||
r'\n+'
|
||||
t.lexer.lineno += t.value.count("\n")
|
||||
|
||||
# Operators
|
||||
t_PLUS = r'\+'
|
||||
t_MINUS = r'-'
|
||||
t_TIMES = r'\*'
|
||||
t_DIVIDE = r'/'
|
||||
t_MOD = r'%'
|
||||
t_OR = r'\|'
|
||||
t_AND = r'&'
|
||||
t_NOT = r'~'
|
||||
t_XOR = r'\^'
|
||||
t_LSHIFT = r'<<'
|
||||
t_RSHIFT = r'>>'
|
||||
t_LOR = r'\|\|'
|
||||
t_LAND = r'&&'
|
||||
t_LNOT = r'!'
|
||||
t_LT = r'<'
|
||||
t_GT = r'>'
|
||||
t_LE = r'<='
|
||||
t_GE = r'>='
|
||||
t_EQ = r'=='
|
||||
t_NE = r'!='
|
||||
|
||||
# Assignment operators
|
||||
|
||||
t_EQUALS = r'='
|
||||
t_TIMESEQUAL = r'\*='
|
||||
t_DIVEQUAL = r'/='
|
||||
t_MODEQUAL = r'%='
|
||||
t_PLUSEQUAL = r'\+='
|
||||
t_MINUSEQUAL = r'-='
|
||||
t_LSHIFTEQUAL = r'<<='
|
||||
t_RSHIFTEQUAL = r'>>='
|
||||
t_ANDEQUAL = r'&='
|
||||
t_OREQUAL = r'\|='
|
||||
t_XOREQUAL = r'\^='
|
||||
|
||||
# Increment/decrement
|
||||
t_PLUSPLUS = r'\+\+'
|
||||
t_MINUSMINUS = r'--'
|
||||
|
||||
# ->
|
||||
t_ARROW = r'->'
|
||||
|
||||
# ?
|
||||
t_CONDOP = r'\?'
|
||||
|
||||
# Delimeters
|
||||
t_LPAREN = r'\('
|
||||
t_RPAREN = r'\)'
|
||||
t_LBRACKET = r'\['
|
||||
t_RBRACKET = r'\]'
|
||||
t_LBRACE = r'\{'
|
||||
t_RBRACE = r'\}'
|
||||
t_COMMA = r','
|
||||
t_PERIOD = r'\.'
|
||||
t_SEMI = r';'
|
||||
t_COLON = r':'
|
||||
t_ELLIPSIS = r'\.\.\.'
|
||||
|
||||
# Identifiers and reserved words
|
||||
|
||||
reserved_map = {}
|
||||
for r in reserved:
|
||||
reserved_map[r.lower()] = r
|
||||
|
||||
|
||||
def t_ID(t):
|
||||
r'[A-Za-z_][\w_]*'
|
||||
t.type = reserved_map.get(t.value, "ID")
|
||||
return t
|
||||
|
||||
# Integer literal
|
||||
t_ICONST = r'\d+([uU]|[lL]|[uU][lL]|[lL][uU])?'
|
||||
|
||||
# Floating literal
|
||||
t_FCONST = r'((\d+)(\.\d+)(e(\+|-)?(\d+))? | (\d+)e(\+|-)?(\d+))([lL]|[fF])?'
|
||||
|
||||
# String literal
|
||||
t_SCONST = r'\"([^\\\n]|(\\.))*?\"'
|
||||
|
||||
# Character constant 'c' or L'c'
|
||||
t_CCONST = r'(L)?\'([^\\\n]|(\\.))*?\''
|
||||
|
||||
# Comments
|
||||
|
||||
|
||||
def t_comment(t):
|
||||
r'/\*(.|\n)*?\*/'
|
||||
t.lexer.lineno += t.value.count('\n')
|
||||
|
||||
# Preprocessor directive (ignored)
|
||||
|
||||
|
||||
def t_preprocessor(t):
|
||||
r'\#(.)*?\n'
|
||||
t.lexer.lineno += 1
|
||||
|
||||
|
||||
def t_error(t):
|
||||
print("Illegal character %s" % repr(t.value[0]))
|
||||
t.lexer.skip(1)
|
||||
|
||||
lexer = lex.lex()
|
||||
if __name__ == "__main__":
|
||||
lex.runmain(lexer)
|
||||
1048
components/script/dom/bindings/codegen/ply/example/ansic/cparse.py
Normal file
1048
components/script/dom/bindings/codegen/ply/example/ansic/cparse.py
Normal file
File diff suppressed because it is too large
Load diff
123
components/script/dom/bindings/codegen/ply/example/calc/calc.py
Normal file
123
components/script/dom/bindings/codegen/ply/example/calc/calc.py
Normal file
|
|
@ -0,0 +1,123 @@
|
|||
# -----------------------------------------------------------------------------
|
||||
# calc.py
|
||||
#
|
||||
# A simple calculator with variables. This is from O'Reilly's
|
||||
# "Lex and Yacc", p. 63.
|
||||
# -----------------------------------------------------------------------------
|
||||
|
||||
import sys
|
||||
sys.path.insert(0, "../..")
|
||||
|
||||
if sys.version_info[0] >= 3:
|
||||
raw_input = input
|
||||
|
||||
tokens = (
|
||||
'NAME', 'NUMBER',
|
||||
)
|
||||
|
||||
literals = ['=', '+', '-', '*', '/', '(', ')']
|
||||
|
||||
# Tokens
|
||||
|
||||
t_NAME = r'[a-zA-Z_][a-zA-Z0-9_]*'
|
||||
|
||||
|
||||
def t_NUMBER(t):
|
||||
r'\d+'
|
||||
t.value = int(t.value)
|
||||
return t
|
||||
|
||||
t_ignore = " \t"
|
||||
|
||||
|
||||
def t_newline(t):
|
||||
r'\n+'
|
||||
t.lexer.lineno += t.value.count("\n")
|
||||
|
||||
|
||||
def t_error(t):
|
||||
print("Illegal character '%s'" % t.value[0])
|
||||
t.lexer.skip(1)
|
||||
|
||||
# Build the lexer
|
||||
import ply.lex as lex
|
||||
lex.lex()
|
||||
|
||||
# Parsing rules
|
||||
|
||||
precedence = (
|
||||
('left', '+', '-'),
|
||||
('left', '*', '/'),
|
||||
('right', 'UMINUS'),
|
||||
)
|
||||
|
||||
# dictionary of names
|
||||
names = {}
|
||||
|
||||
|
||||
def p_statement_assign(p):
|
||||
'statement : NAME "=" expression'
|
||||
names[p[1]] = p[3]
|
||||
|
||||
|
||||
def p_statement_expr(p):
|
||||
'statement : expression'
|
||||
print(p[1])
|
||||
|
||||
|
||||
def p_expression_binop(p):
|
||||
'''expression : expression '+' expression
|
||||
| expression '-' expression
|
||||
| expression '*' expression
|
||||
| expression '/' expression'''
|
||||
if p[2] == '+':
|
||||
p[0] = p[1] + p[3]
|
||||
elif p[2] == '-':
|
||||
p[0] = p[1] - p[3]
|
||||
elif p[2] == '*':
|
||||
p[0] = p[1] * p[3]
|
||||
elif p[2] == '/':
|
||||
p[0] = p[1] / p[3]
|
||||
|
||||
|
||||
def p_expression_uminus(p):
|
||||
"expression : '-' expression %prec UMINUS"
|
||||
p[0] = -p[2]
|
||||
|
||||
|
||||
def p_expression_group(p):
|
||||
"expression : '(' expression ')'"
|
||||
p[0] = p[2]
|
||||
|
||||
|
||||
def p_expression_number(p):
|
||||
"expression : NUMBER"
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
def p_expression_name(p):
|
||||
"expression : NAME"
|
||||
try:
|
||||
p[0] = names[p[1]]
|
||||
except LookupError:
|
||||
print("Undefined name '%s'" % p[1])
|
||||
p[0] = 0
|
||||
|
||||
|
||||
def p_error(p):
|
||||
if p:
|
||||
print("Syntax error at '%s'" % p.value)
|
||||
else:
|
||||
print("Syntax error at EOF")
|
||||
|
||||
import ply.yacc as yacc
|
||||
yacc.yacc()
|
||||
|
||||
while 1:
|
||||
try:
|
||||
s = raw_input('calc > ')
|
||||
except EOFError:
|
||||
break
|
||||
if not s:
|
||||
continue
|
||||
yacc.parse(s)
|
||||
|
|
@ -0,0 +1,129 @@
|
|||
# -----------------------------------------------------------------------------
|
||||
# calc.py
|
||||
#
|
||||
# This example shows how to run the parser in a debugging mode
|
||||
# with output routed to a logging object.
|
||||
# -----------------------------------------------------------------------------
|
||||
|
||||
import sys
|
||||
sys.path.insert(0, "../..")
|
||||
|
||||
if sys.version_info[0] >= 3:
|
||||
raw_input = input
|
||||
|
||||
tokens = (
|
||||
'NAME', 'NUMBER',
|
||||
)
|
||||
|
||||
literals = ['=', '+', '-', '*', '/', '(', ')']
|
||||
|
||||
# Tokens
|
||||
|
||||
t_NAME = r'[a-zA-Z_][a-zA-Z0-9_]*'
|
||||
|
||||
|
||||
def t_NUMBER(t):
|
||||
r'\d+'
|
||||
t.value = int(t.value)
|
||||
return t
|
||||
|
||||
t_ignore = " \t"
|
||||
|
||||
|
||||
def t_newline(t):
|
||||
r'\n+'
|
||||
t.lexer.lineno += t.value.count("\n")
|
||||
|
||||
|
||||
def t_error(t):
|
||||
print("Illegal character '%s'" % t.value[0])
|
||||
t.lexer.skip(1)
|
||||
|
||||
# Build the lexer
|
||||
import ply.lex as lex
|
||||
lex.lex()
|
||||
|
||||
# Parsing rules
|
||||
|
||||
precedence = (
|
||||
('left', '+', '-'),
|
||||
('left', '*', '/'),
|
||||
('right', 'UMINUS'),
|
||||
)
|
||||
|
||||
# dictionary of names
|
||||
names = {}
|
||||
|
||||
|
||||
def p_statement_assign(p):
|
||||
'statement : NAME "=" expression'
|
||||
names[p[1]] = p[3]
|
||||
|
||||
|
||||
def p_statement_expr(p):
|
||||
'statement : expression'
|
||||
print(p[1])
|
||||
|
||||
|
||||
def p_expression_binop(p):
|
||||
'''expression : expression '+' expression
|
||||
| expression '-' expression
|
||||
| expression '*' expression
|
||||
| expression '/' expression'''
|
||||
if p[2] == '+':
|
||||
p[0] = p[1] + p[3]
|
||||
elif p[2] == '-':
|
||||
p[0] = p[1] - p[3]
|
||||
elif p[2] == '*':
|
||||
p[0] = p[1] * p[3]
|
||||
elif p[2] == '/':
|
||||
p[0] = p[1] / p[3]
|
||||
|
||||
|
||||
def p_expression_uminus(p):
|
||||
"expression : '-' expression %prec UMINUS"
|
||||
p[0] = -p[2]
|
||||
|
||||
|
||||
def p_expression_group(p):
|
||||
"expression : '(' expression ')'"
|
||||
p[0] = p[2]
|
||||
|
||||
|
||||
def p_expression_number(p):
|
||||
"expression : NUMBER"
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
def p_expression_name(p):
|
||||
"expression : NAME"
|
||||
try:
|
||||
p[0] = names[p[1]]
|
||||
except LookupError:
|
||||
print("Undefined name '%s'" % p[1])
|
||||
p[0] = 0
|
||||
|
||||
|
||||
def p_error(p):
|
||||
if p:
|
||||
print("Syntax error at '%s'" % p.value)
|
||||
else:
|
||||
print("Syntax error at EOF")
|
||||
|
||||
import ply.yacc as yacc
|
||||
yacc.yacc()
|
||||
|
||||
import logging
|
||||
logging.basicConfig(
|
||||
level=logging.INFO,
|
||||
filename="parselog.txt"
|
||||
)
|
||||
|
||||
while 1:
|
||||
try:
|
||||
s = raw_input('calc > ')
|
||||
except EOFError:
|
||||
break
|
||||
if not s:
|
||||
continue
|
||||
yacc.parse(s, debug=logging.getLogger())
|
||||
|
|
@ -0,0 +1,132 @@
|
|||
# -----------------------------------------------------------------------------
|
||||
# calc.py
|
||||
#
|
||||
# A simple calculator with variables. Asks the user for more input and
|
||||
# demonstrates the use of the t_eof() rule.
|
||||
# -----------------------------------------------------------------------------
|
||||
|
||||
import sys
|
||||
sys.path.insert(0, "../..")
|
||||
|
||||
if sys.version_info[0] >= 3:
|
||||
raw_input = input
|
||||
|
||||
tokens = (
|
||||
'NAME', 'NUMBER',
|
||||
)
|
||||
|
||||
literals = ['=', '+', '-', '*', '/', '(', ')']
|
||||
|
||||
# Tokens
|
||||
|
||||
t_NAME = r'[a-zA-Z_][a-zA-Z0-9_]*'
|
||||
|
||||
|
||||
def t_NUMBER(t):
|
||||
r'\d+'
|
||||
t.value = int(t.value)
|
||||
return t
|
||||
|
||||
t_ignore = " \t"
|
||||
|
||||
|
||||
def t_newline(t):
|
||||
r'\n+'
|
||||
t.lexer.lineno += t.value.count("\n")
|
||||
|
||||
|
||||
def t_eof(t):
|
||||
more = raw_input('... ')
|
||||
if more:
|
||||
t.lexer.input(more + '\n')
|
||||
return t.lexer.token()
|
||||
else:
|
||||
return None
|
||||
|
||||
|
||||
def t_error(t):
|
||||
print("Illegal character '%s'" % t.value[0])
|
||||
t.lexer.skip(1)
|
||||
|
||||
# Build the lexer
|
||||
import ply.lex as lex
|
||||
lex.lex()
|
||||
|
||||
# Parsing rules
|
||||
|
||||
precedence = (
|
||||
('left', '+', '-'),
|
||||
('left', '*', '/'),
|
||||
('right', 'UMINUS'),
|
||||
)
|
||||
|
||||
# dictionary of names
|
||||
names = {}
|
||||
|
||||
|
||||
def p_statement_assign(p):
|
||||
'statement : NAME "=" expression'
|
||||
names[p[1]] = p[3]
|
||||
|
||||
|
||||
def p_statement_expr(p):
|
||||
'statement : expression'
|
||||
print(p[1])
|
||||
|
||||
|
||||
def p_expression_binop(p):
|
||||
'''expression : expression '+' expression
|
||||
| expression '-' expression
|
||||
| expression '*' expression
|
||||
| expression '/' expression'''
|
||||
if p[2] == '+':
|
||||
p[0] = p[1] + p[3]
|
||||
elif p[2] == '-':
|
||||
p[0] = p[1] - p[3]
|
||||
elif p[2] == '*':
|
||||
p[0] = p[1] * p[3]
|
||||
elif p[2] == '/':
|
||||
p[0] = p[1] / p[3]
|
||||
|
||||
|
||||
def p_expression_uminus(p):
|
||||
"expression : '-' expression %prec UMINUS"
|
||||
p[0] = -p[2]
|
||||
|
||||
|
||||
def p_expression_group(p):
|
||||
"expression : '(' expression ')'"
|
||||
p[0] = p[2]
|
||||
|
||||
|
||||
def p_expression_number(p):
|
||||
"expression : NUMBER"
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
def p_expression_name(p):
|
||||
"expression : NAME"
|
||||
try:
|
||||
p[0] = names[p[1]]
|
||||
except LookupError:
|
||||
print("Undefined name '%s'" % p[1])
|
||||
p[0] = 0
|
||||
|
||||
|
||||
def p_error(p):
|
||||
if p:
|
||||
print("Syntax error at '%s'" % p.value)
|
||||
else:
|
||||
print("Syntax error at EOF")
|
||||
|
||||
import ply.yacc as yacc
|
||||
yacc.yacc()
|
||||
|
||||
while 1:
|
||||
try:
|
||||
s = raw_input('calc > ')
|
||||
except EOFError:
|
||||
break
|
||||
if not s:
|
||||
continue
|
||||
yacc.parse(s + '\n')
|
||||
165
components/script/dom/bindings/codegen/ply/example/classcalc/calc.py
Executable file
165
components/script/dom/bindings/codegen/ply/example/classcalc/calc.py
Executable file
|
|
@ -0,0 +1,165 @@
|
|||
#!/usr/bin/env python
|
||||
|
||||
# -----------------------------------------------------------------------------
|
||||
# calc.py
|
||||
#
|
||||
# A simple calculator with variables. This is from O'Reilly's
|
||||
# "Lex and Yacc", p. 63.
|
||||
#
|
||||
# Class-based example contributed to PLY by David McNab
|
||||
# -----------------------------------------------------------------------------
|
||||
|
||||
import sys
|
||||
sys.path.insert(0, "../..")
|
||||
|
||||
if sys.version_info[0] >= 3:
|
||||
raw_input = input
|
||||
|
||||
import ply.lex as lex
|
||||
import ply.yacc as yacc
|
||||
import os
|
||||
|
||||
|
||||
class Parser:
|
||||
"""
|
||||
Base class for a lexer/parser that has the rules defined as methods
|
||||
"""
|
||||
tokens = ()
|
||||
precedence = ()
|
||||
|
||||
def __init__(self, **kw):
|
||||
self.debug = kw.get('debug', 0)
|
||||
self.names = {}
|
||||
try:
|
||||
modname = os.path.split(os.path.splitext(__file__)[0])[
|
||||
1] + "_" + self.__class__.__name__
|
||||
except:
|
||||
modname = "parser" + "_" + self.__class__.__name__
|
||||
self.debugfile = modname + ".dbg"
|
||||
self.tabmodule = modname + "_" + "parsetab"
|
||||
# print self.debugfile, self.tabmodule
|
||||
|
||||
# Build the lexer and parser
|
||||
lex.lex(module=self, debug=self.debug)
|
||||
yacc.yacc(module=self,
|
||||
debug=self.debug,
|
||||
debugfile=self.debugfile,
|
||||
tabmodule=self.tabmodule)
|
||||
|
||||
def run(self):
|
||||
while 1:
|
||||
try:
|
||||
s = raw_input('calc > ')
|
||||
except EOFError:
|
||||
break
|
||||
if not s:
|
||||
continue
|
||||
yacc.parse(s)
|
||||
|
||||
|
||||
class Calc(Parser):
|
||||
|
||||
tokens = (
|
||||
'NAME', 'NUMBER',
|
||||
'PLUS', 'MINUS', 'EXP', 'TIMES', 'DIVIDE', 'EQUALS',
|
||||
'LPAREN', 'RPAREN',
|
||||
)
|
||||
|
||||
# Tokens
|
||||
|
||||
t_PLUS = r'\+'
|
||||
t_MINUS = r'-'
|
||||
t_EXP = r'\*\*'
|
||||
t_TIMES = r'\*'
|
||||
t_DIVIDE = r'/'
|
||||
t_EQUALS = r'='
|
||||
t_LPAREN = r'\('
|
||||
t_RPAREN = r'\)'
|
||||
t_NAME = r'[a-zA-Z_][a-zA-Z0-9_]*'
|
||||
|
||||
def t_NUMBER(self, t):
|
||||
r'\d+'
|
||||
try:
|
||||
t.value = int(t.value)
|
||||
except ValueError:
|
||||
print("Integer value too large %s" % t.value)
|
||||
t.value = 0
|
||||
# print "parsed number %s" % repr(t.value)
|
||||
return t
|
||||
|
||||
t_ignore = " \t"
|
||||
|
||||
def t_newline(self, t):
|
||||
r'\n+'
|
||||
t.lexer.lineno += t.value.count("\n")
|
||||
|
||||
def t_error(self, t):
|
||||
print("Illegal character '%s'" % t.value[0])
|
||||
t.lexer.skip(1)
|
||||
|
||||
# Parsing rules
|
||||
|
||||
precedence = (
|
||||
('left', 'PLUS', 'MINUS'),
|
||||
('left', 'TIMES', 'DIVIDE'),
|
||||
('left', 'EXP'),
|
||||
('right', 'UMINUS'),
|
||||
)
|
||||
|
||||
def p_statement_assign(self, p):
|
||||
'statement : NAME EQUALS expression'
|
||||
self.names[p[1]] = p[3]
|
||||
|
||||
def p_statement_expr(self, p):
|
||||
'statement : expression'
|
||||
print(p[1])
|
||||
|
||||
def p_expression_binop(self, p):
|
||||
"""
|
||||
expression : expression PLUS expression
|
||||
| expression MINUS expression
|
||||
| expression TIMES expression
|
||||
| expression DIVIDE expression
|
||||
| expression EXP expression
|
||||
"""
|
||||
# print [repr(p[i]) for i in range(0,4)]
|
||||
if p[2] == '+':
|
||||
p[0] = p[1] + p[3]
|
||||
elif p[2] == '-':
|
||||
p[0] = p[1] - p[3]
|
||||
elif p[2] == '*':
|
||||
p[0] = p[1] * p[3]
|
||||
elif p[2] == '/':
|
||||
p[0] = p[1] / p[3]
|
||||
elif p[2] == '**':
|
||||
p[0] = p[1] ** p[3]
|
||||
|
||||
def p_expression_uminus(self, p):
|
||||
'expression : MINUS expression %prec UMINUS'
|
||||
p[0] = -p[2]
|
||||
|
||||
def p_expression_group(self, p):
|
||||
'expression : LPAREN expression RPAREN'
|
||||
p[0] = p[2]
|
||||
|
||||
def p_expression_number(self, p):
|
||||
'expression : NUMBER'
|
||||
p[0] = p[1]
|
||||
|
||||
def p_expression_name(self, p):
|
||||
'expression : NAME'
|
||||
try:
|
||||
p[0] = self.names[p[1]]
|
||||
except LookupError:
|
||||
print("Undefined name '%s'" % p[1])
|
||||
p[0] = 0
|
||||
|
||||
def p_error(self, p):
|
||||
if p:
|
||||
print("Syntax error at '%s'" % p.value)
|
||||
else:
|
||||
print("Syntax error at EOF")
|
||||
|
||||
if __name__ == '__main__':
|
||||
calc = Calc()
|
||||
calc.run()
|
||||
2
components/script/dom/bindings/codegen/ply/example/cleanup.sh
Executable file
2
components/script/dom/bindings/codegen/ply/example/cleanup.sh
Executable file
|
|
@ -0,0 +1,2 @@
|
|||
#!/bin/sh
|
||||
rm -f */*.pyc */parsetab.py */parser.out */*~ */*.class
|
||||
|
|
@ -0,0 +1,132 @@
|
|||
# -----------------------------------------------------------------------------
|
||||
# calc.py
|
||||
#
|
||||
# A calculator parser that makes use of closures. The function make_calculator()
|
||||
# returns a function that accepts an input string and returns a result. All
|
||||
# lexing rules, parsing rules, and internal state are held inside the function.
|
||||
# -----------------------------------------------------------------------------
|
||||
|
||||
import sys
|
||||
sys.path.insert(0, "../..")
|
||||
|
||||
if sys.version_info[0] >= 3:
|
||||
raw_input = input
|
||||
|
||||
# Make a calculator function
|
||||
|
||||
|
||||
def make_calculator():
|
||||
import ply.lex as lex
|
||||
import ply.yacc as yacc
|
||||
|
||||
# ------- Internal calculator state
|
||||
|
||||
variables = {} # Dictionary of stored variables
|
||||
|
||||
# ------- Calculator tokenizing rules
|
||||
|
||||
tokens = (
|
||||
'NAME', 'NUMBER',
|
||||
)
|
||||
|
||||
literals = ['=', '+', '-', '*', '/', '(', ')']
|
||||
|
||||
t_ignore = " \t"
|
||||
|
||||
t_NAME = r'[a-zA-Z_][a-zA-Z0-9_]*'
|
||||
|
||||
def t_NUMBER(t):
|
||||
r'\d+'
|
||||
t.value = int(t.value)
|
||||
return t
|
||||
|
||||
def t_newline(t):
|
||||
r'\n+'
|
||||
t.lexer.lineno += t.value.count("\n")
|
||||
|
||||
def t_error(t):
|
||||
print("Illegal character '%s'" % t.value[0])
|
||||
t.lexer.skip(1)
|
||||
|
||||
# Build the lexer
|
||||
lexer = lex.lex()
|
||||
|
||||
# ------- Calculator parsing rules
|
||||
|
||||
precedence = (
|
||||
('left', '+', '-'),
|
||||
('left', '*', '/'),
|
||||
('right', 'UMINUS'),
|
||||
)
|
||||
|
||||
def p_statement_assign(p):
|
||||
'statement : NAME "=" expression'
|
||||
variables[p[1]] = p[3]
|
||||
p[0] = None
|
||||
|
||||
def p_statement_expr(p):
|
||||
'statement : expression'
|
||||
p[0] = p[1]
|
||||
|
||||
def p_expression_binop(p):
|
||||
'''expression : expression '+' expression
|
||||
| expression '-' expression
|
||||
| expression '*' expression
|
||||
| expression '/' expression'''
|
||||
if p[2] == '+':
|
||||
p[0] = p[1] + p[3]
|
||||
elif p[2] == '-':
|
||||
p[0] = p[1] - p[3]
|
||||
elif p[2] == '*':
|
||||
p[0] = p[1] * p[3]
|
||||
elif p[2] == '/':
|
||||
p[0] = p[1] / p[3]
|
||||
|
||||
def p_expression_uminus(p):
|
||||
"expression : '-' expression %prec UMINUS"
|
||||
p[0] = -p[2]
|
||||
|
||||
def p_expression_group(p):
|
||||
"expression : '(' expression ')'"
|
||||
p[0] = p[2]
|
||||
|
||||
def p_expression_number(p):
|
||||
"expression : NUMBER"
|
||||
p[0] = p[1]
|
||||
|
||||
def p_expression_name(p):
|
||||
"expression : NAME"
|
||||
try:
|
||||
p[0] = variables[p[1]]
|
||||
except LookupError:
|
||||
print("Undefined name '%s'" % p[1])
|
||||
p[0] = 0
|
||||
|
||||
def p_error(p):
|
||||
if p:
|
||||
print("Syntax error at '%s'" % p.value)
|
||||
else:
|
||||
print("Syntax error at EOF")
|
||||
|
||||
# Build the parser
|
||||
parser = yacc.yacc()
|
||||
|
||||
# ------- Input function
|
||||
|
||||
def input(text):
|
||||
result = parser.parse(text, lexer=lexer)
|
||||
return result
|
||||
|
||||
return input
|
||||
|
||||
# Make a calculator object and use it
|
||||
calc = make_calculator()
|
||||
|
||||
while True:
|
||||
try:
|
||||
s = raw_input("calc > ")
|
||||
except EOFError:
|
||||
break
|
||||
r = calc(s)
|
||||
if r:
|
||||
print(r)
|
||||
|
|
@ -0,0 +1,48 @@
|
|||
# -----------------------------------------------------------------------------
|
||||
# hedit.py
|
||||
#
|
||||
# Paring of Fortran H Edit descriptions (Contributed by Pearu Peterson)
|
||||
#
|
||||
# These tokens can't be easily tokenized because they are of the following
|
||||
# form:
|
||||
#
|
||||
# nHc1...cn
|
||||
#
|
||||
# where n is a positive integer and c1 ... cn are characters.
|
||||
#
|
||||
# This example shows how to modify the state of the lexer to parse
|
||||
# such tokens
|
||||
# -----------------------------------------------------------------------------
|
||||
|
||||
import sys
|
||||
sys.path.insert(0, "../..")
|
||||
|
||||
|
||||
tokens = (
|
||||
'H_EDIT_DESCRIPTOR',
|
||||
)
|
||||
|
||||
# Tokens
|
||||
t_ignore = " \t\n"
|
||||
|
||||
|
||||
def t_H_EDIT_DESCRIPTOR(t):
|
||||
r"\d+H.*" # This grabs all of the remaining text
|
||||
i = t.value.index('H')
|
||||
n = eval(t.value[:i])
|
||||
|
||||
# Adjust the tokenizing position
|
||||
t.lexer.lexpos -= len(t.value) - (i + 1 + n)
|
||||
|
||||
t.value = t.value[i + 1:i + 1 + n]
|
||||
return t
|
||||
|
||||
|
||||
def t_error(t):
|
||||
print("Illegal character '%s'" % t.value[0])
|
||||
t.lexer.skip(1)
|
||||
|
||||
# Build the lexer
|
||||
import ply.lex as lex
|
||||
lex.lex()
|
||||
lex.runmain()
|
||||
167
components/script/dom/bindings/codegen/ply/example/newclasscalc/calc.py
Executable file
167
components/script/dom/bindings/codegen/ply/example/newclasscalc/calc.py
Executable file
|
|
@ -0,0 +1,167 @@
|
|||
#!/usr/bin/env python
|
||||
|
||||
# -----------------------------------------------------------------------------
|
||||
# calc.py
|
||||
#
|
||||
# A simple calculator with variables. This is from O'Reilly's
|
||||
# "Lex and Yacc", p. 63.
|
||||
#
|
||||
# Class-based example contributed to PLY by David McNab.
|
||||
#
|
||||
# Modified to use new-style classes. Test case.
|
||||
# -----------------------------------------------------------------------------
|
||||
|
||||
import sys
|
||||
sys.path.insert(0, "../..")
|
||||
|
||||
if sys.version_info[0] >= 3:
|
||||
raw_input = input
|
||||
|
||||
import ply.lex as lex
|
||||
import ply.yacc as yacc
|
||||
import os
|
||||
|
||||
|
||||
class Parser(object):
|
||||
"""
|
||||
Base class for a lexer/parser that has the rules defined as methods
|
||||
"""
|
||||
tokens = ()
|
||||
precedence = ()
|
||||
|
||||
def __init__(self, **kw):
|
||||
self.debug = kw.get('debug', 0)
|
||||
self.names = {}
|
||||
try:
|
||||
modname = os.path.split(os.path.splitext(__file__)[0])[
|
||||
1] + "_" + self.__class__.__name__
|
||||
except:
|
||||
modname = "parser" + "_" + self.__class__.__name__
|
||||
self.debugfile = modname + ".dbg"
|
||||
self.tabmodule = modname + "_" + "parsetab"
|
||||
# print self.debugfile, self.tabmodule
|
||||
|
||||
# Build the lexer and parser
|
||||
lex.lex(module=self, debug=self.debug)
|
||||
yacc.yacc(module=self,
|
||||
debug=self.debug,
|
||||
debugfile=self.debugfile,
|
||||
tabmodule=self.tabmodule)
|
||||
|
||||
def run(self):
|
||||
while 1:
|
||||
try:
|
||||
s = raw_input('calc > ')
|
||||
except EOFError:
|
||||
break
|
||||
if not s:
|
||||
continue
|
||||
yacc.parse(s)
|
||||
|
||||
|
||||
class Calc(Parser):
|
||||
|
||||
tokens = (
|
||||
'NAME', 'NUMBER',
|
||||
'PLUS', 'MINUS', 'EXP', 'TIMES', 'DIVIDE', 'EQUALS',
|
||||
'LPAREN', 'RPAREN',
|
||||
)
|
||||
|
||||
# Tokens
|
||||
|
||||
t_PLUS = r'\+'
|
||||
t_MINUS = r'-'
|
||||
t_EXP = r'\*\*'
|
||||
t_TIMES = r'\*'
|
||||
t_DIVIDE = r'/'
|
||||
t_EQUALS = r'='
|
||||
t_LPAREN = r'\('
|
||||
t_RPAREN = r'\)'
|
||||
t_NAME = r'[a-zA-Z_][a-zA-Z0-9_]*'
|
||||
|
||||
def t_NUMBER(self, t):
|
||||
r'\d+'
|
||||
try:
|
||||
t.value = int(t.value)
|
||||
except ValueError:
|
||||
print("Integer value too large %s" % t.value)
|
||||
t.value = 0
|
||||
# print "parsed number %s" % repr(t.value)
|
||||
return t
|
||||
|
||||
t_ignore = " \t"
|
||||
|
||||
def t_newline(self, t):
|
||||
r'\n+'
|
||||
t.lexer.lineno += t.value.count("\n")
|
||||
|
||||
def t_error(self, t):
|
||||
print("Illegal character '%s'" % t.value[0])
|
||||
t.lexer.skip(1)
|
||||
|
||||
# Parsing rules
|
||||
|
||||
precedence = (
|
||||
('left', 'PLUS', 'MINUS'),
|
||||
('left', 'TIMES', 'DIVIDE'),
|
||||
('left', 'EXP'),
|
||||
('right', 'UMINUS'),
|
||||
)
|
||||
|
||||
def p_statement_assign(self, p):
|
||||
'statement : NAME EQUALS expression'
|
||||
self.names[p[1]] = p[3]
|
||||
|
||||
def p_statement_expr(self, p):
|
||||
'statement : expression'
|
||||
print(p[1])
|
||||
|
||||
def p_expression_binop(self, p):
|
||||
"""
|
||||
expression : expression PLUS expression
|
||||
| expression MINUS expression
|
||||
| expression TIMES expression
|
||||
| expression DIVIDE expression
|
||||
| expression EXP expression
|
||||
"""
|
||||
# print [repr(p[i]) for i in range(0,4)]
|
||||
if p[2] == '+':
|
||||
p[0] = p[1] + p[3]
|
||||
elif p[2] == '-':
|
||||
p[0] = p[1] - p[3]
|
||||
elif p[2] == '*':
|
||||
p[0] = p[1] * p[3]
|
||||
elif p[2] == '/':
|
||||
p[0] = p[1] / p[3]
|
||||
elif p[2] == '**':
|
||||
p[0] = p[1] ** p[3]
|
||||
|
||||
def p_expression_uminus(self, p):
|
||||
'expression : MINUS expression %prec UMINUS'
|
||||
p[0] = -p[2]
|
||||
|
||||
def p_expression_group(self, p):
|
||||
'expression : LPAREN expression RPAREN'
|
||||
p[0] = p[2]
|
||||
|
||||
def p_expression_number(self, p):
|
||||
'expression : NUMBER'
|
||||
p[0] = p[1]
|
||||
|
||||
def p_expression_name(self, p):
|
||||
'expression : NAME'
|
||||
try:
|
||||
p[0] = self.names[p[1]]
|
||||
except LookupError:
|
||||
print("Undefined name '%s'" % p[1])
|
||||
p[0] = 0
|
||||
|
||||
def p_error(self, p):
|
||||
if p:
|
||||
print("Syntax error at '%s'" % p.value)
|
||||
else:
|
||||
print("Syntax error at EOF")
|
||||
|
||||
if __name__ == '__main__':
|
||||
calc = Calc()
|
||||
calc.run()
|
||||
|
|
@ -0,0 +1,9 @@
|
|||
An example showing how to use Python optimized mode.
|
||||
To run:
|
||||
|
||||
- First run 'python calc.py'
|
||||
|
||||
- Then run 'python -OO calc.py'
|
||||
|
||||
If working correctly, the second version should run the
|
||||
same way.
|
||||
|
|
@ -0,0 +1,134 @@
|
|||
# -----------------------------------------------------------------------------
|
||||
# calc.py
|
||||
#
|
||||
# A simple calculator with variables. This is from O'Reilly's
|
||||
# "Lex and Yacc", p. 63.
|
||||
# -----------------------------------------------------------------------------
|
||||
|
||||
import sys
|
||||
sys.path.insert(0, "../..")
|
||||
|
||||
if sys.version_info[0] >= 3:
|
||||
raw_input = input
|
||||
|
||||
tokens = (
|
||||
'NAME', 'NUMBER',
|
||||
'PLUS', 'MINUS', 'TIMES', 'DIVIDE', 'EQUALS',
|
||||
'LPAREN', 'RPAREN',
|
||||
)
|
||||
|
||||
# Tokens
|
||||
|
||||
t_PLUS = r'\+'
|
||||
t_MINUS = r'-'
|
||||
t_TIMES = r'\*'
|
||||
t_DIVIDE = r'/'
|
||||
t_EQUALS = r'='
|
||||
t_LPAREN = r'\('
|
||||
t_RPAREN = r'\)'
|
||||
t_NAME = r'[a-zA-Z_][a-zA-Z0-9_]*'
|
||||
|
||||
|
||||
def t_NUMBER(t):
|
||||
r'\d+'
|
||||
try:
|
||||
t.value = int(t.value)
|
||||
except ValueError:
|
||||
print("Integer value too large %s" % t.value)
|
||||
t.value = 0
|
||||
return t
|
||||
|
||||
t_ignore = " \t"
|
||||
|
||||
|
||||
def t_newline(t):
|
||||
r'\n+'
|
||||
t.lexer.lineno += t.value.count("\n")
|
||||
|
||||
|
||||
def t_error(t):
|
||||
print("Illegal character '%s'" % t.value[0])
|
||||
t.lexer.skip(1)
|
||||
|
||||
# Build the lexer
|
||||
import ply.lex as lex
|
||||
lex.lex(optimize=1)
|
||||
|
||||
# Parsing rules
|
||||
|
||||
precedence = (
|
||||
('left', 'PLUS', 'MINUS'),
|
||||
('left', 'TIMES', 'DIVIDE'),
|
||||
('right', 'UMINUS'),
|
||||
)
|
||||
|
||||
# dictionary of names
|
||||
names = {}
|
||||
|
||||
|
||||
def p_statement_assign(t):
|
||||
'statement : NAME EQUALS expression'
|
||||
names[t[1]] = t[3]
|
||||
|
||||
|
||||
def p_statement_expr(t):
|
||||
'statement : expression'
|
||||
print(t[1])
|
||||
|
||||
|
||||
def p_expression_binop(t):
|
||||
'''expression : expression PLUS expression
|
||||
| expression MINUS expression
|
||||
| expression TIMES expression
|
||||
| expression DIVIDE expression'''
|
||||
if t[2] == '+':
|
||||
t[0] = t[1] + t[3]
|
||||
elif t[2] == '-':
|
||||
t[0] = t[1] - t[3]
|
||||
elif t[2] == '*':
|
||||
t[0] = t[1] * t[3]
|
||||
elif t[2] == '/':
|
||||
t[0] = t[1] / t[3]
|
||||
elif t[2] == '<':
|
||||
t[0] = t[1] < t[3]
|
||||
|
||||
|
||||
def p_expression_uminus(t):
|
||||
'expression : MINUS expression %prec UMINUS'
|
||||
t[0] = -t[2]
|
||||
|
||||
|
||||
def p_expression_group(t):
|
||||
'expression : LPAREN expression RPAREN'
|
||||
t[0] = t[2]
|
||||
|
||||
|
||||
def p_expression_number(t):
|
||||
'expression : NUMBER'
|
||||
t[0] = t[1]
|
||||
|
||||
|
||||
def p_expression_name(t):
|
||||
'expression : NAME'
|
||||
try:
|
||||
t[0] = names[t[1]]
|
||||
except LookupError:
|
||||
print("Undefined name '%s'" % t[1])
|
||||
t[0] = 0
|
||||
|
||||
|
||||
def p_error(t):
|
||||
if t:
|
||||
print("Syntax error at '%s'" % t.value)
|
||||
else:
|
||||
print("Syntax error at EOF")
|
||||
|
||||
import ply.yacc as yacc
|
||||
yacc.yacc(optimize=1)
|
||||
|
||||
while 1:
|
||||
try:
|
||||
s = raw_input('calc > ')
|
||||
except EOFError:
|
||||
break
|
||||
yacc.parse(s)
|
||||
|
|
@ -0,0 +1,133 @@
|
|||
# -----------------------------------------------------------------------------
|
||||
# calc.py
|
||||
#
|
||||
# A simple calculator with variables. This is from O'Reilly's
|
||||
# "Lex and Yacc", p. 63.
|
||||
#
|
||||
# This example uses unicode strings for tokens, docstrings, and input.
|
||||
# -----------------------------------------------------------------------------
|
||||
|
||||
import sys
|
||||
sys.path.insert(0, "../..")
|
||||
|
||||
tokens = (
|
||||
'NAME', 'NUMBER',
|
||||
'PLUS', 'MINUS', 'TIMES', 'DIVIDE', 'EQUALS',
|
||||
'LPAREN', 'RPAREN',
|
||||
)
|
||||
|
||||
# Tokens
|
||||
|
||||
t_PLUS = ur'\+'
|
||||
t_MINUS = ur'-'
|
||||
t_TIMES = ur'\*'
|
||||
t_DIVIDE = ur'/'
|
||||
t_EQUALS = ur'='
|
||||
t_LPAREN = ur'\('
|
||||
t_RPAREN = ur'\)'
|
||||
t_NAME = ur'[a-zA-Z_][a-zA-Z0-9_]*'
|
||||
|
||||
|
||||
def t_NUMBER(t):
|
||||
ur'\d+'
|
||||
try:
|
||||
t.value = int(t.value)
|
||||
except ValueError:
|
||||
print "Integer value too large", t.value
|
||||
t.value = 0
|
||||
return t
|
||||
|
||||
t_ignore = u" \t"
|
||||
|
||||
|
||||
def t_newline(t):
|
||||
ur'\n+'
|
||||
t.lexer.lineno += t.value.count("\n")
|
||||
|
||||
|
||||
def t_error(t):
|
||||
print "Illegal character '%s'" % t.value[0]
|
||||
t.lexer.skip(1)
|
||||
|
||||
# Build the lexer
|
||||
import ply.lex as lex
|
||||
lex.lex()
|
||||
|
||||
# Parsing rules
|
||||
|
||||
precedence = (
|
||||
('left', 'PLUS', 'MINUS'),
|
||||
('left', 'TIMES', 'DIVIDE'),
|
||||
('right', 'UMINUS'),
|
||||
)
|
||||
|
||||
# dictionary of names
|
||||
names = {}
|
||||
|
||||
|
||||
def p_statement_assign(p):
|
||||
'statement : NAME EQUALS expression'
|
||||
names[p[1]] = p[3]
|
||||
|
||||
|
||||
def p_statement_expr(p):
|
||||
'statement : expression'
|
||||
print p[1]
|
||||
|
||||
|
||||
def p_expression_binop(p):
|
||||
'''expression : expression PLUS expression
|
||||
| expression MINUS expression
|
||||
| expression TIMES expression
|
||||
| expression DIVIDE expression'''
|
||||
if p[2] == u'+':
|
||||
p[0] = p[1] + p[3]
|
||||
elif p[2] == u'-':
|
||||
p[0] = p[1] - p[3]
|
||||
elif p[2] == u'*':
|
||||
p[0] = p[1] * p[3]
|
||||
elif p[2] == u'/':
|
||||
p[0] = p[1] / p[3]
|
||||
|
||||
|
||||
def p_expression_uminus(p):
|
||||
'expression : MINUS expression %prec UMINUS'
|
||||
p[0] = -p[2]
|
||||
|
||||
|
||||
def p_expression_group(p):
|
||||
'expression : LPAREN expression RPAREN'
|
||||
p[0] = p[2]
|
||||
|
||||
|
||||
def p_expression_number(p):
|
||||
'expression : NUMBER'
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
def p_expression_name(p):
|
||||
'expression : NAME'
|
||||
try:
|
||||
p[0] = names[p[1]]
|
||||
except LookupError:
|
||||
print "Undefined name '%s'" % p[1]
|
||||
p[0] = 0
|
||||
|
||||
|
||||
def p_error(p):
|
||||
if p:
|
||||
print "Syntax error at '%s'" % p.value
|
||||
else:
|
||||
print "Syntax error at EOF"
|
||||
|
||||
import ply.yacc as yacc
|
||||
yacc.yacc()
|
||||
|
||||
while 1:
|
||||
try:
|
||||
s = raw_input('calc > ')
|
||||
except EOFError:
|
||||
break
|
||||
if not s:
|
||||
continue
|
||||
yacc.parse(unicode(s))
|
||||
|
|
@ -0,0 +1,41 @@
|
|||
yply.py
|
||||
|
||||
This example implements a program yply.py that converts a UNIX-yacc
|
||||
specification file into a PLY-compatible program. To use, simply
|
||||
run it like this:
|
||||
|
||||
% python yply.py [-nocode] inputfile.y >myparser.py
|
||||
|
||||
The output of this program is Python code. In the output,
|
||||
any C code in the original file is included, but is commented out.
|
||||
If you use the -nocode option, then all of the C code in the
|
||||
original file is just discarded.
|
||||
|
||||
To use the resulting grammer with PLY, you'll need to edit the
|
||||
myparser.py file. Within this file, some stub code is included that
|
||||
can be used to test the construction of the parsing tables. However,
|
||||
you'll need to do more editing to make a workable parser.
|
||||
|
||||
Disclaimer: This just an example I threw together in an afternoon.
|
||||
It might have some bugs. However, it worked when I tried it on
|
||||
a yacc-specified C++ parser containing 442 rules and 855 parsing
|
||||
states.
|
||||
|
||||
Comments:
|
||||
|
||||
1. This example does not parse specification files meant for lex/flex.
|
||||
You'll need to specify the tokenizer on your own.
|
||||
|
||||
2. This example shows a number of interesting PLY features including
|
||||
|
||||
- Parsing of literal text delimited by nested parentheses
|
||||
- Some interaction between the parser and the lexer.
|
||||
- Use of literals in the grammar specification
|
||||
- One pass compilation. The program just emits the result,
|
||||
there is no intermediate parse tree.
|
||||
|
||||
3. This program could probably be cleaned up and enhanced a lot.
|
||||
It would be great if someone wanted to work on this (hint).
|
||||
|
||||
-Dave
|
||||
|
||||
119
components/script/dom/bindings/codegen/ply/example/yply/ylex.py
Normal file
119
components/script/dom/bindings/codegen/ply/example/yply/ylex.py
Normal file
|
|
@ -0,0 +1,119 @@
|
|||
# lexer for yacc-grammars
|
||||
#
|
||||
# Author: David Beazley (dave@dabeaz.com)
|
||||
# Date : October 2, 2006
|
||||
|
||||
import sys
|
||||
sys.path.append("../..")
|
||||
|
||||
from ply import *
|
||||
|
||||
tokens = (
|
||||
'LITERAL', 'SECTION', 'TOKEN', 'LEFT', 'RIGHT', 'PREC', 'START', 'TYPE', 'NONASSOC', 'UNION', 'CODE',
|
||||
'ID', 'QLITERAL', 'NUMBER',
|
||||
)
|
||||
|
||||
states = (('code', 'exclusive'),)
|
||||
|
||||
literals = [';', ',', '<', '>', '|', ':']
|
||||
t_ignore = ' \t'
|
||||
|
||||
t_TOKEN = r'%token'
|
||||
t_LEFT = r'%left'
|
||||
t_RIGHT = r'%right'
|
||||
t_NONASSOC = r'%nonassoc'
|
||||
t_PREC = r'%prec'
|
||||
t_START = r'%start'
|
||||
t_TYPE = r'%type'
|
||||
t_UNION = r'%union'
|
||||
t_ID = r'[a-zA-Z_][a-zA-Z_0-9]*'
|
||||
t_QLITERAL = r'''(?P<quote>['"]).*?(?P=quote)'''
|
||||
t_NUMBER = r'\d+'
|
||||
|
||||
|
||||
def t_SECTION(t):
|
||||
r'%%'
|
||||
if getattr(t.lexer, "lastsection", 0):
|
||||
t.value = t.lexer.lexdata[t.lexpos + 2:]
|
||||
t.lexer.lexpos = len(t.lexer.lexdata)
|
||||
else:
|
||||
t.lexer.lastsection = 0
|
||||
return t
|
||||
|
||||
# Comments
|
||||
|
||||
|
||||
def t_ccomment(t):
|
||||
r'/\*(.|\n)*?\*/'
|
||||
t.lexer.lineno += t.value.count('\n')
|
||||
|
||||
t_ignore_cppcomment = r'//.*'
|
||||
|
||||
|
||||
def t_LITERAL(t):
|
||||
r'%\{(.|\n)*?%\}'
|
||||
t.lexer.lineno += t.value.count("\n")
|
||||
return t
|
||||
|
||||
|
||||
def t_NEWLINE(t):
|
||||
r'\n'
|
||||
t.lexer.lineno += 1
|
||||
|
||||
|
||||
def t_code(t):
|
||||
r'\{'
|
||||
t.lexer.codestart = t.lexpos
|
||||
t.lexer.level = 1
|
||||
t.lexer.begin('code')
|
||||
|
||||
|
||||
def t_code_ignore_string(t):
|
||||
r'\"([^\\\n]|(\\.))*?\"'
|
||||
|
||||
|
||||
def t_code_ignore_char(t):
|
||||
r'\'([^\\\n]|(\\.))*?\''
|
||||
|
||||
|
||||
def t_code_ignore_comment(t):
|
||||
r'/\*(.|\n)*?\*/'
|
||||
|
||||
|
||||
def t_code_ignore_cppcom(t):
|
||||
r'//.*'
|
||||
|
||||
|
||||
def t_code_lbrace(t):
|
||||
r'\{'
|
||||
t.lexer.level += 1
|
||||
|
||||
|
||||
def t_code_rbrace(t):
|
||||
r'\}'
|
||||
t.lexer.level -= 1
|
||||
if t.lexer.level == 0:
|
||||
t.type = 'CODE'
|
||||
t.value = t.lexer.lexdata[t.lexer.codestart:t.lexpos + 1]
|
||||
t.lexer.begin('INITIAL')
|
||||
t.lexer.lineno += t.value.count('\n')
|
||||
return t
|
||||
|
||||
t_code_ignore_nonspace = r'[^\s\}\'\"\{]+'
|
||||
t_code_ignore_whitespace = r'\s+'
|
||||
t_code_ignore = ""
|
||||
|
||||
|
||||
def t_code_error(t):
|
||||
raise RuntimeError
|
||||
|
||||
|
||||
def t_error(t):
|
||||
print("%d: Illegal character '%s'" % (t.lexer.lineno, t.value[0]))
|
||||
print(t.value)
|
||||
t.lexer.skip(1)
|
||||
|
||||
lex.lex()
|
||||
|
||||
if __name__ == '__main__':
|
||||
lex.runmain()
|
||||
|
|
@ -0,0 +1,244 @@
|
|||
# parser for Unix yacc-based grammars
|
||||
#
|
||||
# Author: David Beazley (dave@dabeaz.com)
|
||||
# Date : October 2, 2006
|
||||
|
||||
import ylex
|
||||
tokens = ylex.tokens
|
||||
|
||||
from ply import *
|
||||
|
||||
tokenlist = []
|
||||
preclist = []
|
||||
|
||||
emit_code = 1
|
||||
|
||||
|
||||
def p_yacc(p):
|
||||
'''yacc : defsection rulesection'''
|
||||
|
||||
|
||||
def p_defsection(p):
|
||||
'''defsection : definitions SECTION
|
||||
| SECTION'''
|
||||
p.lexer.lastsection = 1
|
||||
print("tokens = ", repr(tokenlist))
|
||||
print()
|
||||
print("precedence = ", repr(preclist))
|
||||
print()
|
||||
print("# -------------- RULES ----------------")
|
||||
print()
|
||||
|
||||
|
||||
def p_rulesection(p):
|
||||
'''rulesection : rules SECTION'''
|
||||
|
||||
print("# -------------- RULES END ----------------")
|
||||
print_code(p[2], 0)
|
||||
|
||||
|
||||
def p_definitions(p):
|
||||
'''definitions : definitions definition
|
||||
| definition'''
|
||||
|
||||
|
||||
def p_definition_literal(p):
|
||||
'''definition : LITERAL'''
|
||||
print_code(p[1], 0)
|
||||
|
||||
|
||||
def p_definition_start(p):
|
||||
'''definition : START ID'''
|
||||
print("start = '%s'" % p[2])
|
||||
|
||||
|
||||
def p_definition_token(p):
|
||||
'''definition : toktype opttype idlist optsemi '''
|
||||
for i in p[3]:
|
||||
if i[0] not in "'\"":
|
||||
tokenlist.append(i)
|
||||
if p[1] == '%left':
|
||||
preclist.append(('left',) + tuple(p[3]))
|
||||
elif p[1] == '%right':
|
||||
preclist.append(('right',) + tuple(p[3]))
|
||||
elif p[1] == '%nonassoc':
|
||||
preclist.append(('nonassoc',) + tuple(p[3]))
|
||||
|
||||
|
||||
def p_toktype(p):
|
||||
'''toktype : TOKEN
|
||||
| LEFT
|
||||
| RIGHT
|
||||
| NONASSOC'''
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
def p_opttype(p):
|
||||
'''opttype : '<' ID '>'
|
||||
| empty'''
|
||||
|
||||
|
||||
def p_idlist(p):
|
||||
'''idlist : idlist optcomma tokenid
|
||||
| tokenid'''
|
||||
if len(p) == 2:
|
||||
p[0] = [p[1]]
|
||||
else:
|
||||
p[0] = p[1]
|
||||
p[1].append(p[3])
|
||||
|
||||
|
||||
def p_tokenid(p):
|
||||
'''tokenid : ID
|
||||
| ID NUMBER
|
||||
| QLITERAL
|
||||
| QLITERAL NUMBER'''
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
def p_optsemi(p):
|
||||
'''optsemi : ';'
|
||||
| empty'''
|
||||
|
||||
|
||||
def p_optcomma(p):
|
||||
'''optcomma : ','
|
||||
| empty'''
|
||||
|
||||
|
||||
def p_definition_type(p):
|
||||
'''definition : TYPE '<' ID '>' namelist optsemi'''
|
||||
# type declarations are ignored
|
||||
|
||||
|
||||
def p_namelist(p):
|
||||
'''namelist : namelist optcomma ID
|
||||
| ID'''
|
||||
|
||||
|
||||
def p_definition_union(p):
|
||||
'''definition : UNION CODE optsemi'''
|
||||
# Union declarations are ignored
|
||||
|
||||
|
||||
def p_rules(p):
|
||||
'''rules : rules rule
|
||||
| rule'''
|
||||
if len(p) == 2:
|
||||
rule = p[1]
|
||||
else:
|
||||
rule = p[2]
|
||||
|
||||
# Print out a Python equivalent of this rule
|
||||
|
||||
embedded = [] # Embedded actions (a mess)
|
||||
embed_count = 0
|
||||
|
||||
rulename = rule[0]
|
||||
rulecount = 1
|
||||
for r in rule[1]:
|
||||
# r contains one of the rule possibilities
|
||||
print("def p_%s_%d(p):" % (rulename, rulecount))
|
||||
prod = []
|
||||
prodcode = ""
|
||||
for i in range(len(r)):
|
||||
item = r[i]
|
||||
if item[0] == '{': # A code block
|
||||
if i == len(r) - 1:
|
||||
prodcode = item
|
||||
break
|
||||
else:
|
||||
# an embedded action
|
||||
embed_name = "_embed%d_%s" % (embed_count, rulename)
|
||||
prod.append(embed_name)
|
||||
embedded.append((embed_name, item))
|
||||
embed_count += 1
|
||||
else:
|
||||
prod.append(item)
|
||||
print(" '''%s : %s'''" % (rulename, " ".join(prod)))
|
||||
# Emit code
|
||||
print_code(prodcode, 4)
|
||||
print()
|
||||
rulecount += 1
|
||||
|
||||
for e, code in embedded:
|
||||
print("def p_%s(p):" % e)
|
||||
print(" '''%s : '''" % e)
|
||||
print_code(code, 4)
|
||||
print()
|
||||
|
||||
|
||||
def p_rule(p):
|
||||
'''rule : ID ':' rulelist ';' '''
|
||||
p[0] = (p[1], [p[3]])
|
||||
|
||||
|
||||
def p_rule2(p):
|
||||
'''rule : ID ':' rulelist morerules ';' '''
|
||||
p[4].insert(0, p[3])
|
||||
p[0] = (p[1], p[4])
|
||||
|
||||
|
||||
def p_rule_empty(p):
|
||||
'''rule : ID ':' ';' '''
|
||||
p[0] = (p[1], [[]])
|
||||
|
||||
|
||||
def p_rule_empty2(p):
|
||||
'''rule : ID ':' morerules ';' '''
|
||||
|
||||
p[3].insert(0, [])
|
||||
p[0] = (p[1], p[3])
|
||||
|
||||
|
||||
def p_morerules(p):
|
||||
'''morerules : morerules '|' rulelist
|
||||
| '|' rulelist
|
||||
| '|' '''
|
||||
|
||||
if len(p) == 2:
|
||||
p[0] = [[]]
|
||||
elif len(p) == 3:
|
||||
p[0] = [p[2]]
|
||||
else:
|
||||
p[0] = p[1]
|
||||
p[0].append(p[3])
|
||||
|
||||
# print("morerules", len(p), p[0])
|
||||
|
||||
|
||||
def p_rulelist(p):
|
||||
'''rulelist : rulelist ruleitem
|
||||
| ruleitem'''
|
||||
|
||||
if len(p) == 2:
|
||||
p[0] = [p[1]]
|
||||
else:
|
||||
p[0] = p[1]
|
||||
p[1].append(p[2])
|
||||
|
||||
|
||||
def p_ruleitem(p):
|
||||
'''ruleitem : ID
|
||||
| QLITERAL
|
||||
| CODE
|
||||
| PREC'''
|
||||
p[0] = p[1]
|
||||
|
||||
|
||||
def p_empty(p):
|
||||
'''empty : '''
|
||||
|
||||
|
||||
def p_error(p):
|
||||
pass
|
||||
|
||||
yacc.yacc(debug=0)
|
||||
|
||||
|
||||
def print_code(code, indent):
|
||||
if not emit_code:
|
||||
return
|
||||
codelines = code.splitlines()
|
||||
for c in codelines:
|
||||
print("%s# %s" % (" " * indent, c))
|
||||
51
components/script/dom/bindings/codegen/ply/example/yply/yply.py
Executable file
51
components/script/dom/bindings/codegen/ply/example/yply/yply.py
Executable file
|
|
@ -0,0 +1,51 @@
|
|||
#!/usr/local/bin/python
|
||||
# yply.py
|
||||
#
|
||||
# Author: David Beazley (dave@dabeaz.com)
|
||||
# Date : October 2, 2006
|
||||
#
|
||||
# Converts a UNIX-yacc specification file into a PLY-compatible
|
||||
# specification. To use, simply do this:
|
||||
#
|
||||
# % python yply.py [-nocode] inputfile.y >myparser.py
|
||||
#
|
||||
# The output of this program is Python code. In the output,
|
||||
# any C code in the original file is included, but is commented.
|
||||
# If you use the -nocode option, then all of the C code in the
|
||||
# original file is discarded.
|
||||
#
|
||||
# Disclaimer: This just an example I threw together in an afternoon.
|
||||
# It might have some bugs. However, it worked when I tried it on
|
||||
# a yacc-specified C++ parser containing 442 rules and 855 parsing
|
||||
# states.
|
||||
#
|
||||
|
||||
import sys
|
||||
sys.path.insert(0, "../..")
|
||||
|
||||
import ylex
|
||||
import yparse
|
||||
|
||||
from ply import *
|
||||
|
||||
if len(sys.argv) == 1:
|
||||
print("usage : yply.py [-nocode] inputfile")
|
||||
raise SystemExit
|
||||
|
||||
if len(sys.argv) == 3:
|
||||
if sys.argv[1] == '-nocode':
|
||||
yparse.emit_code = 0
|
||||
else:
|
||||
print("Unknown option '%s'" % sys.argv[1])
|
||||
raise SystemExit
|
||||
filename = sys.argv[2]
|
||||
else:
|
||||
filename = sys.argv[1]
|
||||
|
||||
yacc.parse(open(filename).read())
|
||||
|
||||
print("""
|
||||
if __name__ == '__main__':
|
||||
from ply import *
|
||||
yacc.yacc()
|
||||
""")
|
||||
Loading…
Add table
Add a link
Reference in a new issue