src/doc/book/2018-edition/tools/src/bin/remove_links.rs

   1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 extern crate regex;
  12
  13 use std::io;
  14 use std::io::{Read, Write};
  15 use regex::{Regex, Captures};
  16 use std::collections::HashSet;
  17
  18 fn main () {
  19     let mut buffer = String::new();
  20     if let Err(e) = io::stdin().read_to_string(&mut buffer) {
  21         panic!(e);
  22     }
  23
  24     let mut refs = HashSet::new();
  25
  26     // capture all links and link references
  27     let regex = r"\[([^\]]+)\](?:(?:\[([^\]]+)\])|(?:\([^\)]+\)))(?i)<!-- ignore -->";
  28     let link_regex = Regex::new(regex).unwrap();
  29     let first_pass = link_regex.replace_all(&buffer, |caps: &Captures| {
  30
  31         // save the link reference we want to delete
  32         if let Some(reference) = caps.at(2) {
  33             refs.insert(reference.to_owned());
  34         }
  35
  36         // put the link title back
  37         caps.at(1).unwrap().to_owned()
  38     });
  39
  40     // search for the references we need to delete
  41     let ref_regex = Regex::new(r"\n\[([^\]]+)\]:\s.*\n").unwrap();
  42     let out = ref_regex.replace_all(&first_pass, |caps: &Captures| {
  43         let capture = caps.at(1).unwrap().to_owned();
  44
  45         // check if we've marked this reference for deletion...
  46         if refs.contains(capture.as_str()) {
  47             return "".to_string();
  48         }
  49
  50         //... else we put back everything we captured
  51         caps.at(0).unwrap().to_owned()
  52     });
  53
  54     write!(io::stdout(), "{}", out).unwrap();
  55 }