Class: Neg::Parser::NonTerminalParser

Inherits:
SubParser
  • Object
show all
Defined in:
lib/neg/parser.rb

Instance Method Summary collapse

Methods inherited from SubParser

#*, #+, #-@, #[], #|, #~

Constructor Details

#initialize(name, child = nil) ⇒ NonTerminalParser

Returns a new instance of NonTerminalParser.



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# File 'lib/neg/parser.rb', line 115

def initialize(name, child=nil)

  @name = name
  @child = child
end

Instance Method Details

#==(pa) ⇒ Object 



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# File 'lib/neg/parser.rb', line 121

def ==(pa)

  @child = pa
end

#do_parse(i) ⇒ Object

def reduce(children_results)

  children_results.collect { |cr|
    if cr[0] && cr[0] != :digit
      false
    elsif cr[2]
      cr[3] ? cr[3] : reduce(cr[4])
    else
      nil
    end
  }.flatten.compact
end

Raises:



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# File 'lib/neg/parser.rb', line 139

def do_parse(i)

  raise ParseError.new("\"#{@name}\" is missing") if @child.nil?

  r = @child.do_parse(i)

  return r

#        return r if r[0] == false
#
#        report = reduce(r[2])
#
#        return r if report.include?(false)
#
#        [ true, report.join, [] ]
end

#parse(input_or_string) ⇒ Object 



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# File 'lib/neg/parser.rb', line 156

def parse(input_or_string)

  r = super(input_or_string)
  r[0] = @name

  r
end

#to_s(parent = nil) ⇒ Object 



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# File 'lib/neg/parser.rb', line 164

def to_s(parent=nil)

  child = @child ? @child.to_s(self) : '<missing>'

  if @name.is_a?(String)
    "#{child}[#{@name.inspect}]"
  elsif parent
    @name.to_s
  else #if @name.is_a?(Symbol)
    "#{@name} == #{child}"
  end
end