diff options
Diffstat (limited to 'tool/lrama/lib/lrama/lexer/location.rb')
-rw-r--r-- | tool/lrama/lib/lrama/lexer/location.rb | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/tool/lrama/lib/lrama/lexer/location.rb b/tool/lrama/lib/lrama/lexer/location.rb new file mode 100644 index 0000000000..bf8f4f7e3e --- /dev/null +++ b/tool/lrama/lib/lrama/lexer/location.rb @@ -0,0 +1,99 @@ +# frozen_string_literal: true + +module Lrama + class Lexer + class Location + attr_reader :grammar_file, :first_line, :first_column, :last_line, :last_column + + def initialize(grammar_file:, first_line:, first_column:, last_line:, last_column:) + @grammar_file = grammar_file + @first_line = first_line + @first_column = first_column + @last_line = last_line + @last_column = last_column + end + + def ==(other) + self.class == other.class && + self.grammar_file == other.grammar_file && + self.first_line == other.first_line && + self.first_column == other.first_column && + self.last_line == other.last_line && + self.last_column == other.last_column + end + + def partial_location(left, right) + offset = -first_column + new_first_line = -1 + new_first_column = -1 + new_last_line = -1 + new_last_column = -1 + + _text.each.with_index do |line, index| + new_offset = offset + line.length + 1 + + if offset <= left && left <= new_offset + new_first_line = first_line + index + new_first_column = left - offset + end + + if offset <= right && right <= new_offset + new_last_line = first_line + index + new_last_column = right - offset + end + + offset = new_offset + end + + Location.new( + grammar_file: grammar_file, + first_line: new_first_line, first_column: new_first_column, + last_line: new_last_line, last_column: new_last_column + ) + end + + def to_s + "#{path} (#{first_line},#{first_column})-(#{last_line},#{last_column})" + end + + def generate_error_message(error_message) + <<~ERROR.chomp + #{path}:#{first_line}:#{first_column}: #{error_message} + #{line_with_carets} + ERROR + end + + def line_with_carets + <<~TEXT + #{text} + #{carets} + TEXT + end + + private + + def path + grammar_file.path + end + + def blanks + (text[0...first_column] or raise "#{first_column} is invalid").gsub(/[^\t]/, ' ') + end + + def carets + blanks + '^' * (last_column - first_column) + end + + def text + @text ||= _text.join("\n") + end + + def _text + @_text ||=begin + range = (first_line - 1)...last_line + grammar_file.lines[range] or raise "#{range} is invalid" + end + end + end + end +end |