src/location.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Copyright 2009 Jean-Sebastien Gelinas <calestar@gmail.com>
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 # This module is used to model Nit source-file and locations in source-file
  18 module location
  19
  20 # A raw text Nit source file
  21 class SourceFile
  22         # The path of the source
  23         var filename: String
  24
  25         # The content of the source
  26         var string: String is noinit
  27
  28         # The original stream used to initialize `string`
  29         var stream: IStream
  30
  31         init
  32         do
  33                 string = stream.read_all
  34                 line_starts[0] = 0
  35         end
  36
  37         # Create a new sourcefile using a dummy filename and a given content
  38         init from_string(filename: String, string: String)
  39         do
  40                 self.filename = filename
  41                 self.string = string
  42                 line_starts[0] = 0
  43         end
  44
  45         # Position of each line start
  46         var line_starts = new Array[Int]
  47 end
  48
  49 # A location inside a source file
  50 class Location
  51         super Comparable
  52         redef type OTHER: Location
  53
  54         var file: nullable SourceFile
  55         var line_start: Int
  56         var line_end: Int
  57
  58         # Start of this location on `line_start`
  59         #
  60         # A `column_start` of 1 means the first column or character.
  61         #
  62         # If `column_start == 0` this location concerns the whole line.
  63         #
  64         # Require: `column_start >= 0`
  65         var column_start: Int
  66
  67         var column_end: Int
  68
  69         # The index in the start character in the source
  70         fun pstart: Int do return file.line_starts[line_start-1] + column_start-1
  71
  72         # The index on the end character in the source
  73         fun pend: Int do return file.line_starts[line_end-1] + column_end-1
  74
  75         # The verbatim associated text in the source-file
  76         fun text: String
  77         do
  78                 var res = self.text_cache
  79                 if res != null then return res
  80                 var l = self
  81                 var pstart = self.pstart
  82                 var pend = self.pend
  83                 res = l.file.string.substring(pstart, pend-pstart+1)
  84                 self.text_cache = res
  85                 return res
  86         end
  87
  88         private var text_cache: nullable String = null
  89
  90         init with_file(f: SourceFile) do init(f,0,0,0,0)
  91
  92         redef fun ==(other: nullable Object): Bool do
  93                 if other == null then return false
  94                 if not other isa Location then return false
  95
  96                 if other.file != file then return false
  97                 if other.line_start != line_start then return false
  98                 if other.line_end != line_end then return false
  99                 if other.column_start != column_start then return false
 100                 if other.column_end != column_end then return false
 101
 102                 return true
 103         end
 104
 105         # Is `self` included (or equals) to `loc`?
 106         fun located_in(loc: nullable Location): Bool do
 107                 if loc == null then return false
 108
 109                 if line_start < loc.line_start then return false
 110                 if line_start > loc.line_end then return false
 111
 112                 if line_end > loc.line_end then return false
 113
 114                 if line_start == loc.line_start then
 115                         if column_start < loc.column_start then return false
 116                         if column_start > loc.column_end then return false
 117                 end
 118
 119                 if line_end == loc.line_end and column_end > loc.column_end then return false
 120
 121                 return true
 122         end
 123
 124         redef fun to_s: String do
 125                 var file_part = ""
 126                 if file != null then
 127                         file_part = file.filename
 128                         if file.filename.length > 0 then file_part += ":"
 129                 end
 130
 131                 if line_start == line_end then
 132                         if column_start == column_end then
 133                                 return "{file_part}{line_start},{column_start}"
 134                         else
 135                                 return "{file_part}{line_start},{column_start}--{column_end}"
 136                         end
 137                 else
 138                         return "{file_part}{line_start},{column_start}--{line_end},{column_end}"
 139                 end
 140         end
 141
 142         # Return a location message according to an observer.
 143         #
 144         # Currently, if both are in the same file, the file information is not present in the result.
 145         fun relative_to(loc: nullable Location): String do
 146                 var relative: Location
 147                 if loc != null and loc.file == self.file then
 148                         relative = new Location(null, self.line_start, self.line_end, self.column_start, self.column_end)
 149                 else
 150                         relative = new Location(self.file, self.line_start, self.line_end, self.column_start, self.column_end)
 151                 end
 152                 return relative.to_s
 153         end
 154
 155         redef fun <(other: OTHER): Bool do
 156                 if self == other then return false
 157                 if self.located_in(other) then return true
 158                 if other.located_in(self) then return false
 159
 160                 if line_start != other.line_start then return line_start < other.line_start
 161                 if column_start != other.column_start then return column_start < other.column_start
 162                 if line_end != other.line_end then return line_end < other.line_end
 163
 164                 return column_end < other.column_end
 165         end
 166
 167         # Return the associated line with the location highlighted with color and a caret under the starting position
 168         # `color` must be and terminal escape sequence used as `"{escape}[{color}m;"`
 169         # * `"0;31"` for red
 170         # * `"1;31"` for bright red
 171         # * `"0;32"` for green
 172         fun colored_line(color: String): String
 173         do
 174                 var esc = 27.ascii
 175                 var def = "{esc}[0m"
 176                 var col = "{esc}[{color}m"
 177
 178                 var l = self
 179                 var i = l.line_start
 180                 var line_start = l.file.line_starts[i-1]
 181                 var line_end = line_start
 182                 var string = l.file.string
 183                 while line_end+1 < string.length and string.chars[line_end+1] != '\n' and string.chars[line_end+1] != '\r' do
 184                         line_end += 1
 185                 end
 186                 var lstart
 187                 if l.column_start > 0 then
 188                         lstart = string.substring(line_start, l.column_start - 1)
 189                 else
 190                         lstart = ""
 191                 end
 192                 var cend
 193                 if i != l.line_end then
 194                         cend = line_end - line_start + 1
 195                 else
 196                         cend = l.column_end
 197                 end
 198                 var lmid
 199                 var lend
 200                 if line_start + cend <= string.length then
 201                         lmid = string.substring(line_start + l.column_start - 1, cend - l.column_start + 1)
 202                         lend = string.substring(line_start + cend, line_end - line_start - cend + 1)
 203                 else
 204                         lmid = ""
 205                         lend = ""
 206                 end
 207                 var indent = new FlatBuffer
 208                 for j in [line_start..line_start+l.column_start-1[ do
 209                         if string.chars[j] == '\t' then
 210                                 indent.add '\t'
 211                         else
 212                                 indent.add ' '
 213                         end
 214                 end
 215                 return "\t{lstart}{col}{lmid}{def}{lend}\n\t{indent}^"
 216         end
 217 end