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Diffstat (limited to 'src/io.rs')
| -rw-r--r-- | src/io.rs | 194 |
1 files changed, 0 insertions, 194 deletions
diff --git a/src/io.rs b/src/io.rs deleted file mode 100644 index 5801efaf..00000000 --- a/src/io.rs +++ /dev/null @@ -1,194 +0,0 @@ -// Copyright 2015 The Rust Project Developers. See the COPYRIGHT -// file at the top-level directory of this distribution and at -// http://rust-lang.org/COPYRIGHT. -// -// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or -// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license -// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your -// option. This file may not be copied, modified, or distributed -// except according to those terms. - -//! Unmerged utf8 chars iterator vendored from std::io -//! -use std::io::{BufRead, ErrorKind, Error}; -use std::fmt; -use std::error as std_error; -use std::result; -use std::char; - -static UTF8_CHAR_WIDTH: [u8; 256] = [ -1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, -1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, // 0x1F -1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, -1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, // 0x3F -1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, -1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, // 0x5F -1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, -1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, // 0x7F -0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, -0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 0x9F -0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, -0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 0xBF -0,0,2,2,2,2,2,2,2,2,2,2,2,2,2,2, -2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, // 0xDF -3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, // 0xEF -4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0, // 0xFF -]; - -/// Given a first byte, determine how many bytes are in this UTF-8 character -#[inline] -pub fn utf8_char_width(b: u8) -> usize { - return UTF8_CHAR_WIDTH[b as usize] as usize; -} - -/// An iterator over the `char`s of a reader. -/// -/// This struct is generally created by calling [`utf8_chars()`][utf8_chars] on a reader. -/// Please see the documentation of `utf8_chars()` for more details. -/// -/// [utf8_chars]: trait.BufRead.html#method.utf8_chars -pub struct Utf8Chars<R> { - inner: R, -} - -impl<R> Utf8Chars<R> { - pub fn new(inner: R) -> Utf8Chars<R> { - Utf8Chars { inner: inner } - } -} - -/// An enumeration of possible errors that can be generated from the `Utf8Chars` -/// adapter. -#[derive(Debug)] -pub enum Utf8CharsError { - /// Variant representing that the underlying stream was read successfully - /// but contains a byte sequence ill-formed in UTF-8. - InvalidUtf8, - - /// Variant representing that the underlying stream contains the start - /// of a byte sequence well-formed in UTF-8, but ends prematurely. - /// - /// Contains number of unused bytes - IncompleteUtf8(usize), - - /// Variant representing that an I/O error occurred. - Io(Error), -} - -impl<R: BufRead> Iterator for Utf8Chars<R> { - type Item = result::Result<char, Utf8CharsError>; - - // allow(unused_assignments) because consumed += 1 is not recognized as being used - #[allow(unused_assignments)] - fn next(&mut self) -> Option<result::Result<char, Utf8CharsError>> { - macro_rules! read_byte { - (EOF => $on_eof: expr) => { - { - let byte; - loop { - match self.inner.fill_buf() { - Ok(buffer) => { - if let Some(&b) = buffer.first() { - byte = b; - break - } else { - $on_eof - } - } - Err(ref e) if e.kind() == ErrorKind::Interrupted => {} - Err(e) => return Some(Err(Utf8CharsError::Io(e))), - } - } - byte - } - } - } - - let first = read_byte!(EOF => return None); - self.inner.consume(1); - - let mut consumed = 1; - - macro_rules! continuation_byte { - ($range: pat) => { - { - match read_byte!(EOF => return Some(Err(Utf8CharsError::IncompleteUtf8(consumed)))) { - byte @ $range => { - self.inner.consume(1); - consumed += 1; - (byte & 0b0011_1111) as u32 - } - _ => return Some(Err(Utf8CharsError::InvalidUtf8)) - } - } - } - } - - // Ranges can be checked against https://tools.ietf.org/html/rfc3629#section-4 - let code_point = match utf8_char_width(first) { - 1 => return Some(Ok(first as char)), - 2 => { - let second = continuation_byte!(0x80...0xBF); - ((first & 0b0001_1111) as u32) << 6 | second - } - 3 => { - let second = match first { - 0xE0 => continuation_byte!(0xA0...0xBF), - 0xE1...0xEC => continuation_byte!(0x80...0xBF), - 0xED => continuation_byte!(0x80...0x9F), - 0xEE...0xEF => continuation_byte!(0x80...0xBF), - _ => unreachable!(), - }; - let third = continuation_byte!(0x80...0xBF); - ((first & 0b0000_1111) as u32) << 12 | second << 6 | third - } - 4 => { - let second = match first { - 0xF0 => continuation_byte!(0x90...0xBF), - 0xF0...0xF3 => continuation_byte!(0x80...0xBF), - 0xF4 => continuation_byte!(0x80...0x8F), - _ => unreachable!(), - }; - let third = continuation_byte!(0x80...0xBF); - let fourth = continuation_byte!(0x80...0xBF); - ((first & 0b0000_0111) as u32) << 18 | second << 12 | third << 6 | fourth - } - _ => return Some(Err(Utf8CharsError::InvalidUtf8)) - }; - unsafe { - Some(Ok(char::from_u32_unchecked(code_point))) - } - } -} - -impl std_error::Error for Utf8CharsError { - fn description(&self) -> &str { - match *self { - Utf8CharsError::InvalidUtf8 => "invalid UTF-8 byte sequence", - Utf8CharsError::IncompleteUtf8(_) => { - "stream ended in the middle of an UTF-8 byte sequence" - } - Utf8CharsError::Io(ref e) => std_error::Error::description(e), - } - } - fn cause(&self) -> Option<&std_error::Error> { - match *self { - Utf8CharsError::InvalidUtf8 | Utf8CharsError::IncompleteUtf8(_) => None, - Utf8CharsError::Io(ref e) => e.cause(), - } - } -} - -impl fmt::Display for Utf8CharsError { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - match *self { - Utf8CharsError::InvalidUtf8 => { - "invalid UTF-8 byte sequence".fmt(f) - } - Utf8CharsError::IncompleteUtf8(_) => { - "stream ended in the middle of an UTF-8 byte sequence".fmt(f) - } - Utf8CharsError::Io(ref e) => e.fmt(f), - } - } -} |