+
+ # Return the associated line with the location highlihted with color and a carret under the starting position
+ # `color` must be and terminal escape sequence used as `"{escape}[{color}m;"`
+ # * `"0;31"` for red
+ # * `"1;31"` for bright red
+ # * `"0;32"` for green
+ fun colored_line(color: String): String
+ do
+ var esc = 27.ascii
+ var def = "{esc}[0m"
+ var col = "{esc}[{color}m"
+
+ var l = self
+ var i = l.line_start
+ var line_start = l.file.line_starts[i-1]
+ var line_end = line_start
+ var string = l.file.string
+ while line_end+1 < string.length and string.chars[line_end+1] != '\n' and string.chars[line_end+1] != '\r' do
+ line_end += 1
+ end
+ var lstart = string.substring(line_start, l.column_start - 1)
+ var cend
+ if i != l.line_end then
+ cend = line_end - line_start + 1
+ else
+ cend = l.column_end
+ end
+ var lmid
+ var lend
+ if line_start + cend <= string.length then
+ lmid = string.substring(line_start + l.column_start - 1, cend - l.column_start + 1)
+ lend = string.substring(line_start + cend, line_end - line_start - cend + 1)
+ else
+ lmid = ""
+ lend = ""
+ end
+ var indent = new Buffer
+ for j in [line_start..line_start+l.column_start-1[ do
+ if string.chars[j] == '\t' then
+ indent.add '\t'
+ else
+ indent.add ' '
+ end
+ end
+ return "\t{lstart}{col}{lmid}{def}{lend}\n\t{indent}^"
+ end