Class: Prattle::Parser

Inherits:

Object

• Object
• Prattle::Parser

show all

Defined in:

lib/prattle/parser.rb

Defined Under Namespace

Classes: ParseError

Constant Summary

Grammar =

to_kpeg

Instance Attribute Summary (collapse)

• - (Object) last_match readonly

  Returns the value of attribute last_match.

Class Method Summary (collapse)

• + (Object) register(node)
• + (Object) to_kpeg

Instance Method Summary (collapse)

• - (Parser) initialize(str) constructor

  A new instance of Parser.

• - (Object) parse(rule = nil)

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# File 'lib/prattle/parser.rb', line 25

def initialize(str)
  @parser = KPeg::Parser.new(str, Grammar)
end

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# File 'lib/prattle/parser.rb', line 49

def last_match
  @last_match
end

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# File 'lib/prattle/parser.rb', line 9

def self.register(node)
  @nodes << node
end

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# File 'lib/prattle/parser.rb', line 13

def self.to_kpeg
  gram = KPeg::Grammar.new

  @nodes.each do |node|
    node.grammar(gram)
  end

  AST.grammar(gram)

  gram
end

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# File 'lib/prattle/parser.rb', line 39

def parse(rule=nil)
  @last_match = match = @parser.parse(rule ? rule.to_s : nil)

  if @parser.failed?
    raise ParseError.new(@parser, match)
  end

  return match.value if match
end