src/tools/compiletest/src/uidiff.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 //! Code for checking whether the output of the compiler matches what is
  12 //! expected.
  13
  14 pub fn diff_lines(actual: &str, expected: &str) -> Vec<String> {
  15     // mega simplistic diff algorithm that just prints the things added/removed
  16     zip_all(actual.lines(), expected.lines())
  17         .enumerate()
  18         .filter_map(|(i, (a, e))| {
  19             match (a, e) {
  20                 (Some(a), Some(e)) => {
  21                     if lines_match(e, a) {
  22                         None
  23                     } else {
  24                         Some(format!("{:3} - |{}|\n    + |{}|\n", i, e, a))
  25                     }
  26                 }
  27                 (Some(a), None) => Some(format!("{:3} -\n    + |{}|\n", i, a)),
  28                 (None, Some(e)) => Some(format!("{:3} - |{}|\n    +\n", i, e)),
  29                 (None, None) => panic!("Cannot get here"),
  30             }
  31         })
  32         .collect()
  33 }
  34
  35 fn lines_match(expected: &str, mut actual: &str) -> bool {
  36     for (i, part) in expected.split("[..]").enumerate() {
  37         match actual.find(part) {
  38             Some(j) => {
  39                 if i == 0 && j != 0 {
  40                     return false;
  41                 }
  42                 actual = &actual[j + part.len()..];
  43             }
  44             None => return false,
  45         }
  46     }
  47     actual.is_empty() || expected.ends_with("[..]")
  48 }
  49
  50 struct ZipAll<I1: Iterator, I2: Iterator> {
  51     first: I1,
  52     second: I2,
  53 }
  54
  55 impl<T, I1: Iterator<Item = T>, I2: Iterator<Item = T>> Iterator for ZipAll<I1, I2> {
  56     type Item = (Option<T>, Option<T>);
  57     fn next(&mut self) -> Option<(Option<T>, Option<T>)> {
  58         let first = self.first.next();
  59         let second = self.second.next();
  60
  61         match (first, second) {
  62             (None, None) => None,
  63             (a, b) => Some((a, b)),
  64         }
  65     }
  66 }
  67
  68 fn zip_all<T, I1: Iterator<Item = T>, I2: Iterator<Item = T>>(a: I1, b: I2) -> ZipAll<I1, I2> {
  69     ZipAll {
  70         first: a,
  71         second: b,
  72     }
  73 }