Class: AND

Inherits:
SemanticContext show all
Defined in:
lib/antlr4/atn/SemanticContext.rb

Overview

is false.

Instance Attribute Summary

Attributes inherited from SemanticContext

#opnds

Instance Method Summary collapse

Methods inherited from SemanticContext

NONE, #andContext, andContext, filterPrecedencePredicates, #filterPrecedencePredicates, #orContext, orContext, #simplify

Constructor Details

#initialize(a, b) ⇒ AND

Returns a new instance of AND.



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# File 'lib/antlr4/atn/SemanticContext.rb', line 174

def initialize(a, b)
    operands = Set.new()
    if a.kind_of? AND then
        a.opnds.each {|o| operands.add(o) }
    else
        operands.add(a)
    end
    if b.kind_of? AND then
        b.opnds.each {|o| operands.add(o) }
    else
        operands.add(b)
    end
    precedencePredicates = filterPrecedencePredicates(operands)
    if precedencePredicates.length>0 then
        # interested in the transition with the lowest precedence
        reduced = precedencePredicates.min
        operands.add(reduced)
    end
    @opnds = operands.to_a
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/antlr4/atn/SemanticContext.rb', line 198

def ==(other)
    self.equal?(other) or \
    ( other.kind_of?(AND) and self.opnds == other.opnds )
end

#eql?(other) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/antlr4/atn/SemanticContext.rb', line 195

def eql?(other)
  self == other
end

#eval(parser, outerContext) ⇒ Object

@inheritDoc

<p> The evaluation of predicates by this context is short-circuiting, but unordered.</p>



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# File 'lib/antlr4/atn/SemanticContext.rb', line 214

def eval(parser, outerContext)
    self.opnds.each {|opnd|
        if not opnd.eval(parser, outerContext)
            return false
        end
    }
    return true
end

#evalPrecedence(parser, outerContext) ⇒ Object 



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# File 'lib/antlr4/atn/SemanticContext.rb', line 223

def evalPrecedence(parser, outerContext)
    differs = false
    operands = Array.new
    self.opnds.each {|context|
        evaluated = context.evalPrecedence(parser, outerContext)
        if evaluated.equal? context then
            differs = false
        else
            differs = true
        end
#            differs = differs || (! (evaluated.equal? context))
        # The AND context is false if any element is false
        return nil if evaluated.nil? 
        if evaluated.equal? SemanticContext.NONE
            # Reduce the result by skipping true elements
            operands.push(evaluated)
        end
    }
    if not differs
        return self
    end

    if operands.length()==0
        # all elements were true, so the AND context is true
        return SemanticContext.NONE
    end

    result = nil
    operands.each {|o| 
        if result.nil? 
            result = o 
        else 
          result = result.andContext(o)
        end
    }
    return result
end

#hash ⇒ Object 



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# File 'lib/antlr4/atn/SemanticContext.rb', line 203

def hash 
   "#{self.opnds}/AND".hash
end

#to_s ⇒ Object 



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# File 'lib/antlr4/atn/SemanticContext.rb', line 260

def  to_s
    self.opnds.map(&:to_s).join("&&") 
end