src/missed_spans.rs

   1 // Copyright 2015 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 use utils::make_indent;
  12 use visitor::FmtVisitor;
  13
  14 use syntax::codemap::{self, BytePos};
  15
  16 impl<'a> FmtVisitor<'a> {
  17     // TODO these format_missing methods are ugly. Refactor and add unit tests
  18     // for the central whitespace stripping loop.
  19     pub fn format_missing(&mut self, end: BytePos) {
  20         self.format_missing_inner(end, |this, last_snippet, file_name, _| {
  21             this.changes.push_str(file_name, last_snippet)
  22         })
  23     }
  24
  25     pub fn format_missing_with_indent(&mut self, end: BytePos) {
  26         self.format_missing_inner(end, |this, last_snippet, file_name, snippet| {
  27             this.changes.push_str(file_name, last_snippet.trim_right());
  28             if last_snippet == snippet {
  29                 // No new lines in the snippet.
  30                 this.changes.push_str(file_name, "\n");
  31             }
  32             let indent = make_indent(this.block_indent);
  33             this.changes.push_str(file_name, &indent);
  34         })
  35     }
  36
  37     fn format_missing_inner<F: Fn(&mut FmtVisitor, &str, &str, &str)>(&mut self,
  38                                                                       end: BytePos,
  39                                                                       process_last_snippet: F)
  40     {
  41         let start = self.last_pos;
  42         debug!("format_missing_inner: {:?} to {:?}",
  43                self.codemap.lookup_char_pos(start),
  44                self.codemap.lookup_char_pos(end));
  45
  46         if start == end {
  47             return;
  48         }
  49
  50         assert!(start < end,
  51                 "Request to format inverted span: {:?} to {:?}",
  52                 self.codemap.lookup_char_pos(start),
  53                 self.codemap.lookup_char_pos(end));
  54
  55         self.last_pos = end;
  56         let spans = self.changes.filespans_for_span(start, end);
  57         for (i, &(start, end)) in spans.iter().enumerate() {
  58             let span = codemap::mk_sp(BytePos(start), BytePos(end));
  59             let file_name = &self.codemap.span_to_filename(span);
  60             let snippet = self.snippet(span);
  61
  62             self.write_snippet(&snippet,
  63                                file_name,
  64                                i == spans.len() - 1,
  65                                &process_last_snippet);
  66         }
  67     }
  68
  69     fn write_snippet<F: Fn(&mut FmtVisitor, &str, &str, &str)>(&mut self,
  70                                                                snippet: &str,
  71                                                                file_name: &str,
  72                                                                last_snippet: bool,
  73                                                                process_last_snippet: F) {
  74         // Trim whitespace from the right hand side of each line.
  75         // Annoyingly, the library functions for splitting by lines etc. are not
  76         // quite right, so we must do it ourselves.
  77         let mut line_start = 0;
  78         let mut last_wspace = None;
  79         for (i, c) in snippet.char_indices() {
  80             if c == '\n' {
  81                 if let Some(lw) = last_wspace {
  82                     self.changes.push_str(file_name, &snippet[line_start..lw]);
  83                     self.changes.push_str(file_name, "\n");
  84                 } else {
  85                     self.changes.push_str(file_name, &snippet[line_start..i+1]);
  86                 }
  87
  88                 line_start = i + 1;
  89                 last_wspace = None;
  90             } else {
  91                 if c.is_whitespace() {
  92                     if last_wspace.is_none() {
  93                         last_wspace = Some(i);
  94                     }
  95                 } else {
  96                     last_wspace = None;
  97                 }
  98             }
  99         }
 100         if last_snippet {
 101             process_last_snippet(self, &snippet[line_start..], file_name, snippet);
 102         } else {
 103             self.changes.push_str(file_name, &snippet[line_start..]);
 104         }
 105     }
 106 }