Class: Semantic::AttrGrDepthFirst

Inherits:
Mapper::DepthFirst show all
Defined in:
../lib/attribute_grammar.rb

Overview

This mapper class implements the modified version of the attribute grammar described in: www.cs.bham.ac.uk/~wbl/biblio/gecco2004/WGEW003.pdf and ncra.ucd.ie/downloads/pub/thesisExtGEwithAGs-CRC.pdf

If there is the boolean p._valid attribute defined for the nonterminal symbol expansion, the expansion is considered only if the value of such attribute is ‘true’.

The implementation differs from the original thesis in this aspect: There is no “rollback phase” of semantic attributes processing when the invalid node expansion is reached (ie node._valid==false). Invalid expansions are simply ignored beforehand, no codons are wasted (in another words there are no introns due to the semantic restrictions present in the genotype string.

See the AttributeGrammar class for detailed description of the semantic YAML file. See the Mapper::DepthFirst class for detailed description of the mapper behavior.

Instance Attribute Summary (collapse)

Attributes inherited from Mapper::Generator

#generated_count, #random

Attributes inherited from Mapper::Base

#codon, #complexity, #consume_trivial_codons, #grammar, #mapped_count, #track_support, #track_support_on, #used_length, #wraps_to_fading, #wraps_to_fail

Instance Method Summary (collapse)

Methods included from Mapper::ConstantsNoSupport

#modify_expansion_base, #modify_expansion_generate

Methods inherited from Mapper::Generator

#generate_full, #generate_grow

Constructor Details

- (AttrGrDepthFirst) initialize(grammar)

See Mapper::DepthFirst#new 



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# File '../lib/attribute_grammar.rb', line 48

def initialize( grammar )
  super grammar

  @functions = grammar.semantic_functions
  clear
end

Instance Attribute Details

- (Object) attributes (readonly)

Semantic attributes hash. It maps AttrKey identification to the attribute values. Mainly for debugging and logging purposes. 



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# File '../lib/attribute_grammar.rb', line 57

def attributes
  @attributes
end

Instance Method Details

- (Object) generate(recursivity, required_depth)

See Mapper::DepthFirst#generate 



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# File '../lib/attribute_grammar.rb', line 66

def generate( recursivity, required_depth )   
  clear
  super( recursivity, required_depth )     
end

- (Object) phenotype(genome)

See Mapper::DepthFirst#phenotype 



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# File '../lib/attribute_grammar.rb', line 60

def phenotype genome
  clear
  super( genome )
end