Class: QDA::Backend::NPReader

Inherits:
Object
  • Object
show all
Defined in:
lib/weft/backend/n6.rb

Overview

An implementation of a nested parenthesis reader. This implementation constructs an AST from a data source.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ NPReader

Initialize a new instance of the reader. This does not start the parsing, that is done with the parse method.



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# File 'lib/weft/backend/n6.rb', line 330

def initialize ()
end

Instance Method Details

#parse(string) ⇒ Object

Parse the data contained in the string and return the reference to the top level group.



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# File 'lib/weft/backend/n6.rb', line 335

def parse (string)
		
		@curgroup = nil
		@top = nil

		string.each_byte { |byte|
 
 ch = byte.chr

 if ( ch == '(' ) then
@curgroup = NPNode.new(@curgroup)
if ( @top == nil ) then 
  @top = @curgroup
end

 elsif ( ch == ')' ) then
@curgroup.close
@curgroup = @curgroup.parent

 else
if ( @curgroup != nil ) then
  @curgroup.push(ch)
end

 end
		}

		return @top
end