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https://github.com/RGBCube/uutils-coreutils
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wc: add lines() method for iterating over lines
Add the `WordCountable::lines()` method that returns an iterator over lines of a file-like object. This mirrors the `std::io::BufRead::lines()` method, with some minor differences due to the particular use case of `wc`. This commit also creates a new module, `countable.rs`, to contain the `WordCountable` trait and the new `Lines` struct returned by `lines()`.
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2 changed files with 81 additions and 46 deletions
72
src/uu/wc/src/countable.rs
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72
src/uu/wc/src/countable.rs
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//! Traits and implementations for iterating over lines in a file-like object.
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//!
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//! This module provides a [`WordCountable`] trait and implementations
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//! for some common file-like objects. Use the [`WordCountable::lines`]
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//! method to get an iterator over lines of a file-like object.
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use std::fs::File;
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use std::io::{self, BufRead, BufReader, Read, StdinLock};
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#[cfg(unix)]
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use std::os::unix::io::AsRawFd;
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#[cfg(unix)]
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pub trait WordCountable: AsRawFd + Read {
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type Buffered: BufRead;
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fn lines(self) -> Lines<Self::Buffered>;
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}
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#[cfg(not(unix))]
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pub trait WordCountable: Read {
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type Buffered: BufRead;
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fn lines(self) -> Lines<Self::Buffered>;
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}
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impl WordCountable for StdinLock<'_> {
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type Buffered = Self;
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fn lines(self) -> Lines<Self::Buffered>
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where
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Self: Sized,
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{
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Lines { buf: self }
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}
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}
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impl WordCountable for File {
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type Buffered = BufReader<Self>;
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fn lines(self) -> Lines<Self::Buffered>
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where
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Self: Sized,
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{
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Lines {
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buf: BufReader::new(self),
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}
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}
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}
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/// An iterator over the lines of an instance of `BufRead`.
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///
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/// Similar to [`io::Lines`] but yields each line as a `Vec<u8>` and
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/// includes the newline character (`\n`, the `0xA` byte) that
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/// terminates the line.
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///
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/// [`io::Lines`]:: io::Lines
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pub struct Lines<B> {
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buf: B,
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}
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impl<B: BufRead> Iterator for Lines<B> {
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type Item = io::Result<Vec<u8>>;
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fn next(&mut self) -> Option<Self::Item> {
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let mut line = Vec::new();
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// reading from a TTY seems to raise a condition on, rather than return Some(0) like a file.
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// hence the option wrapped in a result here
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match self.buf.read_until(b'\n', &mut line) {
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Ok(0) => None,
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Ok(_n) => Some(Ok(line)),
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Err(e) => Some(Err(e)),
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}
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}
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}
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@ -11,17 +11,17 @@
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extern crate uucore;
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extern crate uucore;
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mod count_bytes;
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mod count_bytes;
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mod countable;
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use count_bytes::count_bytes_fast;
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use count_bytes::count_bytes_fast;
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use countable::WordCountable;
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use clap::{App, Arg, ArgMatches};
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use clap::{App, Arg, ArgMatches};
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use thiserror::Error;
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use thiserror::Error;
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use std::cmp::max;
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use std::cmp::max;
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use std::fs::File;
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use std::fs::File;
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use std::io::{self, BufRead, BufReader, Read, StdinLock, Write};
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use std::io::{self, Write};
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use std::ops::{Add, AddAssign};
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use std::ops::{Add, AddAssign};
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#[cfg(unix)]
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use std::os::unix::io::AsRawFd;
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use std::path::Path;
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use std::path::Path;
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use std::str::from_utf8;
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use std::str::from_utf8;
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@ -82,32 +82,6 @@ impl Settings {
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}
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}
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}
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}
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#[cfg(unix)]
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trait WordCountable: AsRawFd + Read {
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type Buffered: BufRead;
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fn get_buffered(self) -> Self::Buffered;
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}
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#[cfg(not(unix))]
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trait WordCountable: Read {
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type Buffered: BufRead;
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fn get_buffered(self) -> Self::Buffered;
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}
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impl WordCountable for StdinLock<'_> {
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type Buffered = Self;
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fn get_buffered(self) -> Self::Buffered {
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self
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}
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}
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impl WordCountable for File {
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type Buffered = BufReader<Self>;
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fn get_buffered(self) -> Self::Buffered {
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BufReader::new(self)
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}
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}
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#[derive(Debug, Default, Copy, Clone)]
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#[derive(Debug, Default, Copy, Clone)]
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struct WordCount {
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struct WordCount {
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bytes: usize,
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bytes: usize,
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@ -270,25 +244,16 @@ fn word_count_from_reader<T: WordCountable>(
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let mut byte_count: usize = 0;
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let mut byte_count: usize = 0;
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let mut char_count: usize = 0;
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let mut char_count: usize = 0;
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let mut longest_line_length: usize = 0;
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let mut longest_line_length: usize = 0;
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let mut raw_line = Vec::new();
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let mut ends_lf: bool;
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let mut ends_lf: bool;
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// reading from a TTY seems to raise a condition on, rather than return Some(0) like a file.
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// reading from a TTY seems to raise a condition on, rather than return Some(0) like a file.
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// hence the option wrapped in a result here
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// hence the option wrapped in a result here
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let mut buffered_reader = reader.get_buffered();
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for line_result in reader.lines() {
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loop {
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let raw_line = match line_result {
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match buffered_reader.read_until(LF, &mut raw_line) {
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Ok(l) => l,
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Ok(n) => {
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Err(e) => {
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if n == 0 {
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show_warning!("Error while reading {}: {}", path, e);
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break;
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continue;
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}
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}
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Err(ref e) => {
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if !raw_line.is_empty() {
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show_warning!("Error while reading {}: {}", path, e);
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} else {
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break;
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}
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}
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}
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};
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};
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@ -317,8 +282,6 @@ fn word_count_from_reader<T: WordCountable>(
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longest_line_length = current_char_count - (ends_lf as usize);
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longest_line_length = current_char_count - (ends_lf as usize);
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}
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}
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}
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}
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raw_line.truncate(0);
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}
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}
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Ok(WordCount {
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Ok(WordCount {
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