52949fbf18
Since ' ' is by far one of the most common characters, it is worthwhile to put it first, and short-circuit the rest of the function. On the same JSON benchmark, as the json_perf improvement, reading example.json 10 times from https://code.google.com/p/rapidjson/wiki/Performance. Before: 0.16s After: 0.11s
429 lines
13 KiB
Rust
429 lines
13 KiB
Rust
// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! Utilities for manipulating the char type
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use option::{None, Option, Some};
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use int;
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use str::StrSlice;
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use unicode::{derived_property, general_category};
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#[cfg(test)] use str::OwnedStr;
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#[cfg(not(test))] use cmp::{Eq, Ord};
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#[cfg(not(test))] use num::Zero;
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/*
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Lu Uppercase_Letter an uppercase letter
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Ll Lowercase_Letter a lowercase letter
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Lt Titlecase_Letter a digraphic character, with first part uppercase
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Lm Modifier_Letter a modifier letter
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Lo Other_Letter other letters, including syllables and ideographs
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Mn Nonspacing_Mark a nonspacing combining mark (zero advance width)
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Mc Spacing_Mark a spacing combining mark (positive advance width)
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Me Enclosing_Mark an enclosing combining mark
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Nd Decimal_Number a decimal digit
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Nl Letter_Number a letterlike numeric character
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No Other_Number a numeric character of other type
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Pc Connector_Punctuation a connecting punctuation mark, like a tie
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Pd Dash_Punctuation a dash or hyphen punctuation mark
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Ps Open_Punctuation an opening punctuation mark (of a pair)
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Pe Close_Punctuation a closing punctuation mark (of a pair)
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Pi Initial_Punctuation an initial quotation mark
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Pf Final_Punctuation a final quotation mark
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Po Other_Punctuation a punctuation mark of other type
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Sm Math_Symbol a symbol of primarily mathematical use
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Sc Currency_Symbol a currency sign
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Sk Modifier_Symbol a non-letterlike modifier symbol
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So Other_Symbol a symbol of other type
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Zs Space_Separator a space character (of various non-zero widths)
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Zl Line_Separator U+2028 LINE SEPARATOR only
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Zp Paragraph_Separator U+2029 PARAGRAPH SEPARATOR only
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Cc Control a C0 or C1 control code
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Cf Format a format control character
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Cs Surrogate a surrogate code point
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Co Private_Use a private-use character
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Cn Unassigned a reserved unassigned code point or a noncharacter
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*/
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/// Returns whether the specified character is considered a unicode alphabetic
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/// character
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pub fn is_alphabetic(c: char) -> bool { derived_property::Alphabetic(c) }
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#[allow(missing_doc)]
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pub fn is_XID_start(c: char) -> bool { derived_property::XID_Start(c) }
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#[allow(missing_doc)]
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pub fn is_XID_continue(c: char) -> bool { derived_property::XID_Continue(c) }
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///
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/// Indicates whether a character is in lower case, defined
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/// in terms of the Unicode General Category 'Ll'
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///
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#[inline]
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pub fn is_lowercase(c: char) -> bool { general_category::Ll(c) }
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///
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/// Indicates whether a character is in upper case, defined
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/// in terms of the Unicode General Category 'Lu'.
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///
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#[inline]
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pub fn is_uppercase(c: char) -> bool { general_category::Lu(c) }
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///
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/// Indicates whether a character is whitespace. Whitespace is defined in
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/// terms of the Unicode General Categories 'Zs', 'Zl', 'Zp'
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/// additional 'Cc'-category control codes in the range [0x09, 0x0d]
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///
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#[inline]
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pub fn is_whitespace(c: char) -> bool {
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c == ' '
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|| ('\x09' <= c && c <= '\x0d')
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|| general_category::Zs(c)
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|| general_category::Zl(c)
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|| general_category::Zp(c)
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}
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///
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/// Indicates whether a character is alphanumeric. Alphanumericness is
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/// defined in terms of the Unicode General Categories 'Nd', 'Nl', 'No'
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/// and the Derived Core Property 'Alphabetic'.
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///
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#[inline]
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pub fn is_alphanumeric(c: char) -> bool {
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derived_property::Alphabetic(c)
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|| general_category::Nd(c)
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|| general_category::Nl(c)
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|| general_category::No(c)
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}
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/// Indicates whether the character is numeric (Nd, Nl, or No)
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#[inline]
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pub fn is_digit(c: char) -> bool {
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general_category::Nd(c)
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|| general_category::Nl(c)
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|| general_category::No(c)
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}
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///
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/// Checks if a character parses as a numeric digit in the given radix.
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/// Compared to `is_digit()`, this function only recognizes the
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/// characters `0-9`, `a-z` and `A-Z`.
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///
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/// # Return value
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///
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/// Returns `true` if `c` is a valid digit under `radix`, and `false`
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/// otherwise.
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///
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/// # Failure
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///
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/// Fails if given a `radix` > 36.
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///
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/// # Note
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///
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/// This just wraps `to_digit()`.
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///
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#[inline]
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pub fn is_digit_radix(c: char, radix: uint) -> bool {
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match to_digit(c, radix) {
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Some(_) => true,
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None => false,
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}
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}
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///
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/// Convert a char to the corresponding digit.
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///
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/// # Return value
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///
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/// If `c` is between '0' and '9', the corresponding value
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/// between 0 and 9. If `c` is 'a' or 'A', 10. If `c` is
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/// 'b' or 'B', 11, etc. Returns none if the char does not
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/// refer to a digit in the given radix.
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///
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/// # Failure
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///
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/// Fails if given a `radix` outside the range `[0..36]`.
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///
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#[inline]
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pub fn to_digit(c: char, radix: uint) -> Option<uint> {
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if radix > 36 {
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fail!("to_digit: radix %? is to high (maximum 36)", radix);
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}
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let val = match c {
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'0' .. '9' => c as uint - ('0' as uint),
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'a' .. 'z' => c as uint + 10u - ('a' as uint),
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'A' .. 'Z' => c as uint + 10u - ('A' as uint),
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_ => return None,
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};
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if val < radix { Some(val) }
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else { None }
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}
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///
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/// Converts a number to the character representing it.
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///
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/// # Return value
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///
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/// Returns `Some(char)` if `num` represents one digit under `radix`,
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/// using one character of `0-9` or `a-z`, or `None` if it doesn't.
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///
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/// # Failure
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///
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/// Fails if given an `radix` > 36.
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///
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#[inline]
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pub fn from_digit(num: uint, radix: uint) -> Option<char> {
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if radix > 36 {
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fail!("from_digit: radix %? is to high (maximum 36)", num);
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}
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if num < radix {
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if num < 10 {
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Some(('0' as uint + num) as char)
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} else {
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Some(('a' as uint + num - 10u) as char)
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}
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} else {
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None
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}
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}
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///
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/// Return the hexadecimal unicode escape of a char.
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///
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/// The rules are as follows:
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///
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/// - chars in [0,0xff] get 2-digit escapes: `\\xNN`
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/// - chars in [0x100,0xffff] get 4-digit escapes: `\\uNNNN`
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/// - chars above 0x10000 get 8-digit escapes: `\\UNNNNNNNN`
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///
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pub fn escape_unicode(c: char, f: &fn(char)) {
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// avoid calling str::to_str_radix because we don't really need to allocate
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// here.
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f('\\');
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let pad = cond!(
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(c <= '\xff') { f('x'); 2 }
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(c <= '\uffff') { f('u'); 4 }
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_ { f('U'); 8 }
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);
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for int::range_step(4 * (pad - 1), -1, -4) |offset| {
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match ((c as u32) >> offset) & 0xf {
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i @ 0 .. 9 => { f('0' + i as char); }
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i => { f('a' + (i - 10) as char); }
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}
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}
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}
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///
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/// Return a 'default' ASCII and C++11-like char-literal escape of a char.
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///
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/// The default is chosen with a bias toward producing literals that are
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/// legal in a variety of languages, including C++11 and similar C-family
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/// languages. The exact rules are:
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///
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/// - Tab, CR and LF are escaped as '\t', '\r' and '\n' respectively.
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/// - Single-quote, double-quote and backslash chars are backslash-escaped.
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/// - Any other chars in the range [0x20,0x7e] are not escaped.
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/// - Any other chars are given hex unicode escapes; see `escape_unicode`.
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///
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pub fn escape_default(c: char, f: &fn(char)) {
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match c {
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'\t' => { f('\\'); f('t'); }
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'\r' => { f('\\'); f('r'); }
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'\n' => { f('\\'); f('n'); }
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'\\' => { f('\\'); f('\\'); }
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'\'' => { f('\\'); f('\''); }
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'"' => { f('\\'); f('"'); }
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'\x20' .. '\x7e' => { f(c); }
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_ => c.escape_unicode(f),
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}
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}
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/// Returns the amount of bytes this character would need if encoded in utf8
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pub fn len_utf8_bytes(c: char) -> uint {
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static MAX_ONE_B: uint = 128u;
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static MAX_TWO_B: uint = 2048u;
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static MAX_THREE_B: uint = 65536u;
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static MAX_FOUR_B: uint = 2097152u;
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let code = c as uint;
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cond!(
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(code < MAX_ONE_B) { 1u }
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(code < MAX_TWO_B) { 2u }
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(code < MAX_THREE_B) { 3u }
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(code < MAX_FOUR_B) { 4u }
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_ { fail!("invalid character!") }
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)
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}
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#[allow(missing_doc)]
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pub trait Char {
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fn is_alphabetic(&self) -> bool;
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fn is_XID_start(&self) -> bool;
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fn is_XID_continue(&self) -> bool;
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fn is_lowercase(&self) -> bool;
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fn is_uppercase(&self) -> bool;
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fn is_whitespace(&self) -> bool;
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fn is_alphanumeric(&self) -> bool;
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fn is_digit(&self) -> bool;
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fn is_digit_radix(&self, radix: uint) -> bool;
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fn to_digit(&self, radix: uint) -> Option<uint>;
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fn from_digit(num: uint, radix: uint) -> Option<char>;
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fn escape_unicode(&self, f: &fn(char));
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fn escape_default(&self, f: &fn(char));
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fn len_utf8_bytes(&self) -> uint;
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}
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impl Char for char {
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fn is_alphabetic(&self) -> bool { is_alphabetic(*self) }
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fn is_XID_start(&self) -> bool { is_XID_start(*self) }
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fn is_XID_continue(&self) -> bool { is_XID_continue(*self) }
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fn is_lowercase(&self) -> bool { is_lowercase(*self) }
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fn is_uppercase(&self) -> bool { is_uppercase(*self) }
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fn is_whitespace(&self) -> bool { is_whitespace(*self) }
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fn is_alphanumeric(&self) -> bool { is_alphanumeric(*self) }
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fn is_digit(&self) -> bool { is_digit(*self) }
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fn is_digit_radix(&self, radix: uint) -> bool { is_digit_radix(*self, radix) }
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fn to_digit(&self, radix: uint) -> Option<uint> { to_digit(*self, radix) }
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fn from_digit(num: uint, radix: uint) -> Option<char> { from_digit(num, radix) }
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fn escape_unicode(&self, f: &fn(char)) { escape_unicode(*self, f) }
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fn escape_default(&self, f: &fn(char)) { escape_default(*self, f) }
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fn len_utf8_bytes(&self) -> uint { len_utf8_bytes(*self) }
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}
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#[cfg(not(test))]
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impl Eq for char {
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#[inline]
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fn eq(&self, other: &char) -> bool { (*self) == (*other) }
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#[inline]
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fn ne(&self, other: &char) -> bool { (*self) != (*other) }
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}
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#[cfg(not(test))]
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impl Ord for char {
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#[inline]
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fn lt(&self, other: &char) -> bool { *self < *other }
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#[inline]
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fn le(&self, other: &char) -> bool { *self <= *other }
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#[inline]
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fn gt(&self, other: &char) -> bool { *self > *other }
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#[inline]
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fn ge(&self, other: &char) -> bool { *self >= *other }
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}
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#[cfg(not(test))]
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impl Zero for char {
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fn zero() -> char { 0 as char }
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fn is_zero(&self) -> bool { *self == 0 as char }
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}
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#[test]
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fn test_is_lowercase() {
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assert!('a'.is_lowercase());
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assert!('ö'.is_lowercase());
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assert!('ß'.is_lowercase());
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assert!(!'Ü'.is_lowercase());
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assert!(!'P'.is_lowercase());
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}
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#[test]
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fn test_is_uppercase() {
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assert!(!'h'.is_uppercase());
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assert!(!'ä'.is_uppercase());
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assert!(!'ß'.is_uppercase());
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assert!('Ö'.is_uppercase());
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assert!('T'.is_uppercase());
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}
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#[test]
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fn test_is_whitespace() {
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assert!(' '.is_whitespace());
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assert!('\u2007'.is_whitespace());
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assert!('\t'.is_whitespace());
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assert!('\n'.is_whitespace());
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assert!(!'a'.is_whitespace());
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assert!(!'_'.is_whitespace());
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assert!(!'\u0000'.is_whitespace());
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}
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#[test]
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fn test_to_digit() {
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assert_eq!('0'.to_digit(10u), Some(0u));
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assert_eq!('1'.to_digit(2u), Some(1u));
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assert_eq!('2'.to_digit(3u), Some(2u));
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assert_eq!('9'.to_digit(10u), Some(9u));
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assert_eq!('a'.to_digit(16u), Some(10u));
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assert_eq!('A'.to_digit(16u), Some(10u));
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assert_eq!('b'.to_digit(16u), Some(11u));
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assert_eq!('B'.to_digit(16u), Some(11u));
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assert_eq!('z'.to_digit(36u), Some(35u));
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assert_eq!('Z'.to_digit(36u), Some(35u));
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assert_eq!(' '.to_digit(10u), None);
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assert_eq!('$'.to_digit(36u), None);
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}
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#[test]
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fn test_is_digit() {
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assert!('2'.is_digit());
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assert!('7'.is_digit());
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assert!(!'c'.is_digit());
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assert!(!'i'.is_digit());
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assert!(!'z'.is_digit());
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assert!(!'Q'.is_digit());
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}
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#[test]
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fn test_escape_default() {
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fn string(c: char) -> ~str {
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let mut result = ~"";
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do escape_default(c) |c| { result.push_char(c); }
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return result;
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}
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assert_eq!(string('\n'), ~"\\n");
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assert_eq!(string('\r'), ~"\\r");
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assert_eq!(string('\''), ~"\\'");
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assert_eq!(string('"'), ~"\\\"");
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assert_eq!(string(' '), ~" ");
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assert_eq!(string('a'), ~"a");
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assert_eq!(string('~'), ~"~");
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assert_eq!(string('\x00'), ~"\\x00");
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assert_eq!(string('\x1f'), ~"\\x1f");
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assert_eq!(string('\x7f'), ~"\\x7f");
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assert_eq!(string('\xff'), ~"\\xff");
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assert_eq!(string('\u011b'), ~"\\u011b");
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assert_eq!(string('\U0001d4b6'), ~"\\U0001d4b6");
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}
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#[test]
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fn test_escape_unicode() {
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fn string(c: char) -> ~str {
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let mut result = ~"";
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do escape_unicode(c) |c| { result.push_char(c); }
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return result;
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}
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assert_eq!(string('\x00'), ~"\\x00");
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assert_eq!(string('\n'), ~"\\x0a");
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assert_eq!(string(' '), ~"\\x20");
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assert_eq!(string('a'), ~"\\x61");
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assert_eq!(string('\u011b'), ~"\\u011b");
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assert_eq!(string('\U0001d4b6'), ~"\\U0001d4b6");
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}
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