Class: Rubylog::Structure

Inherits:
Object show all
Includes:
Enumerable, Assertable, CompoundTerm, Goal, Term
Defined in:
lib/rubylog/structure.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from CompoundTerm

#rubylog_match_variables

Methods included from Term

#rubylog_dereference, #rubylog_match_variables, #rubylog_resolve_function

Methods included from Goal

#solve, #true?

Methods included from Assertable

#if, #if!, #unless

Constructor Details

#initialize(predicate, functor, *args) ⇒ Structure

Returns a new instance of Structure.



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# File 'lib/rubylog/structure.rb', line 7

def initialize predicate, functor, *args
  #raise Rubylog::TypeError, "functor cannot be #{functor}" unless functor.is_a? Symbol
  @predicate = predicate
  @functor = functor
  @args = args.freeze
  @arity = args.count
end

Instance Attribute Details

#args ⇒ Object (readonly)

data structure



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# File 'lib/rubylog/structure.rb', line 5

def args
  @args
end

#functor ⇒ Object (readonly)

data structure



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# File 'lib/rubylog/structure.rb', line 5

def functor
  @functor
end

#rubylog_variables ⇒ Object (readonly)

Returns the value of attribute rubylog_variables.



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# File 'lib/rubylog/structure.rb', line 78

def rubylog_variables
  @rubylog_variables
end

Instance Method Details

#==(other) ⇒ Object Also known as: eql? 



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# File 'lib/rubylog/structure.rb', line 23

def == other
  other.instance_of? Structure and
  @functor == other.functor and @args == other.args
end

#[](i) ⇒ Object 



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# File 'lib/rubylog/structure.rb', line 19

def [] i
  @args[i]
end

#arity ⇒ Object 



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# File 'lib/rubylog/structure.rb', line 43

def arity
  @arity
end

#hash ⇒ Object 



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# File 'lib/rubylog/structure.rb', line 29

def hash
  @functor.hash ^ @args.hash
end

#indicator ⇒ Object 



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# File 'lib/rubylog/structure.rb', line 47

def indicator
  [@functor, @arity]
end

#inspect ⇒ Object 



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# File 'lib/rubylog/structure.rb', line 33

def inspect
  "#{@args[0].inspect}.#{@functor}#{
    "(#{@args[1..-1].inspect[1..-2]})" if @args.count>1
  }"
end

#predicate ⇒ Object 



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# File 'lib/rubylog/structure.rb', line 15

def predicate
  @predicate 
end

#prove ⇒ Object 



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# File 'lib/rubylog/structure.rb', line 57

def prove
  count = 0
  predicate.call(*@args) { yield; count+=1 }
  count
end

#rubylog_clone(&block) ⇒ Object 



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# File 'lib/rubylog/structure.rb', line 83

def rubylog_clone &block
  block.call Structure.new @predicate, @functor.rubylog_clone(&block),
    *@args.map{|a| a.rubylog_clone &block}
end

#rubylog_deep_dereference ⇒ Object 



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# File 'lib/rubylog/structure.rb', line 88

def rubylog_deep_dereference
  Structure.new @predicate, @functor.rubylog_deep_dereference,
    *@args.rubylog_deep_dereference
end

#rubylog_unify(other) ⇒ Object 



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# File 'lib/rubylog/structure.rb', line 71

def rubylog_unify other
  return super{yield} unless other.instance_of? self.class
  return unless other.functor == @functor
  return unless @arity == other.arity
  @args.rubylog_unify(other.args) { yield }
end

#to_s ⇒ Object 



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# File 'lib/rubylog/structure.rb', line 39

def to_s
  inspect
end