Exception: Grammar::ParserError

Inherits:
StandardError
  • Object
show all
Defined in:
lib/emerald/grammar.rb

Overview

When the parser fails on a line from user input

Direct Known Subclasses

PreProcessorError

Constant Summary collapse

LINES_BEFORE = 
3
LINES_AFTER = 
1

Instance Method Summary collapse

Constructor Details

#initialize(line_number, reason, source) ⇒ ParserError 



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# File 'lib/emerald/grammar.rb', line 26

def initialize(line_number, reason, source)
  @line_number = line_number
  @reason = reason
  @source = source
end

Instance Method Details

#message ⇒ Object 



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# File 'lib/emerald/grammar.rb', line 32

def message
  messages = []
  if match = @reason.match(/(Expected .+?) at line/)
    messages << match[1]
  else
    messages << @reason
  end

  lines = @source.split(/\n/)
  LINES_BEFORE.downto(1).each do |i|
    messages << '    ' + lines[@line_number - i - 1] if lines[@line_number - i - 1]
  end
  messages << '>>> ' + lines[@line_number - 1]
  1.upto(LINES_AFTER).each do |i|
    messages << '    ' + lines[@line_number + i - 1] if lines[@line_number + i - 1]
  end

  messages.join("\n")
end