Module: MetaParse::ClassMethods

Defined in:
lib/meta_parse.rb

Instance Method Summary collapse

Instance Method Details

#alt(*args) ⇒ Object

Return an AlternativeMatcher.



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# File 'lib/meta_parse.rb', line 64

def alt(*args)
  Matcher.compile([:or, *args])
end

#comp(spec) ⇒ Object

Compile a Matcher spec into corresponding matcher.



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# File 'lib/meta_parse.rb', line 71

def comp(spec)
  Matcher.compile(spec)
end

#match_method(name, &block) ⇒ Object

Defines a method which takes a scanner from provided block. The block passed should return a Matcher or Matcher spec, which is compiled to a Matcher if necessary. The result of calling the defined method is the same as calling match? on the resulting Matcher.



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# File 'lib/meta_parse.rb', line 29

def match_method(name, &block)
  match_spec = yield
  matcher = MetaParse::Matcher.compile(match_spec)
  
  define_matcher_method(name, matcher)
end

#rep(*args, &block) ⇒ Object

Returns a RepetitionMatcher which matches the pattern specified by its arguments zero-or-more-times.



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# File 'lib/meta_parse.rb', line 39

def rep(*args, &block)
  Matcher.compile([:*, *args])
end

#seq(*args, &block) ⇒ Object

Return a SequentialMatcher. If block is supplied, it defines a function which will be passed an array of all matched values and which should return a non-nil result for the match as a whole. Sequential matching with terminal block is the mechanism by which arbitrary values can be produced at any step in parsing.



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# File 'lib/meta_parse.rb', line 49

def seq(*args, &block)
  if block_given?
    wrapped = lambda { |scanner, context|
      result = block.call context.matches
      context.matches = []
      result
    }
    args << wrapped
  end
  Matcher.compile([:and, *args])
end