servo/components/util/str.rs
Matt Brubeck a939cc50bb Fix doctest errors in rustdoc comments
Mostly this disables doctest for comments that are not actually tests.
2014-09-17 14:46:37 -07:00

110 lines
3.1 KiB
Rust

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
use std::iter::Filter;
use std::str::CharSplits;
pub type DOMString = String;
pub type StaticCharVec = &'static [char];
pub type StaticStringVec = &'static [&'static str];
pub fn null_str_as_empty(s: &Option<DOMString>) -> DOMString {
// We don't use map_default because it would allocate "".to_string() even for Some.
match *s {
Some(ref s) => s.clone(),
None => "".to_string()
}
}
pub fn null_str_as_empty_ref<'a>(s: &'a Option<DOMString>) -> &'a str {
match *s {
Some(ref s) => s.as_slice(),
None => ""
}
}
pub fn is_whitespace(s: &str) -> bool {
s.chars().all(|c| match c {
'\u0020' | '\u0009' | '\u000D' | '\u000A' => true,
_ => false
})
}
/// A "space character" according to:
///
/// http://www.whatwg.org/specs/web-apps/current-work/multipage/common-microsyntaxes.html#space-character
pub static HTML_SPACE_CHARACTERS: StaticCharVec = &[
'\u0020',
'\u0009',
'\u000a',
'\u000c',
'\u000d',
];
pub fn split_html_space_chars<'a>(s: &'a str) -> Filter<'a, &'a str, CharSplits<'a, StaticCharVec>> {
s.split(HTML_SPACE_CHARACTERS).filter(|&split| !split.is_empty())
}
/// Shared implementation to parse an integer according to
/// <http://www.whatwg.org/html/#rules-for-parsing-integers> or
/// <http://www.whatwg.org/html/#rules-for-parsing-non-negative-integers>.
fn do_parse_integer<T: Iterator<char>>(input: T) -> Option<i64> {
fn is_ascii_digit(c: &char) -> bool {
match *c {
'0'..'9' => true,
_ => false,
}
}
let mut input = input.skip_while(|c| {
HTML_SPACE_CHARACTERS.iter().any(|s| s == c)
}).peekable();
let sign = match input.peek() {
None => return None,
Some(&'-') => {
input.next();
-1
},
Some(&'+') => {
input.next();
1
},
Some(_) => 1,
};
match input.peek() {
Some(c) if is_ascii_digit(c) => (),
_ => return None,
}
let value = input.take_while(is_ascii_digit).map(|d| {
d as i64 - '0' as i64
}).fold(Some(0i64), |accumulator, d| {
accumulator.and_then(|accumulator| {
accumulator.checked_mul(&10)
}).and_then(|accumulator| {
accumulator.checked_add(&d)
})
});
return value.and_then(|value| value.checked_mul(&sign));
}
/// Parse an integer according to
/// <http://www.whatwg.org/html/#rules-for-parsing-integers>.
pub fn parse_integer<T: Iterator<char>>(input: T) -> Option<i32> {
do_parse_integer(input).and_then(|result| {
result.to_i32()
})
}
/// Parse an integer according to
/// <http://www.whatwg.org/html/#rules-for-parsing-non-negative-integers>.
pub fn parse_unsigned_integer<T: Iterator<char>>(input: T) -> Option<u32> {
do_parse_integer(input).and_then(|result| {
result.to_u32()
})
}