62 lines
1.6 KiB
Ruby
62 lines
1.6 KiB
Ruby
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module Vool
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class IfStatement < Statement
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attr_reader :condition , :if_true , :if_false
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def initialize( cond , if_true , if_false = nil)
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@condition = cond
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@if_true = if_true
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@if_false = if_false
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end
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def to_mom( compiler )
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true_label = Mom::Label.new( self , "true_label_#{object_id.to_s(16)}")
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false_label = Mom::Label.new( self , "false_label_#{object_id.to_s(16)}")
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merge_label = Mom::Label.new( self , "merge_label_#{object_id.to_s(16)}")
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if @condition.is_a?(CallStatement)
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head = @condition.to_mom(compiler)
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head << check_slot(compiler , false_label)
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else
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head = check_slot(compiler , false_label)
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end
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head << true_label
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head << if_true.to_mom(compiler) if @if_true
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head << Mom::Jump.new(merge_label) if @if_false
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head << false_label
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head << if_false.to_mom(compiler) if @if_false
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head << merge_label if @if_false
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head
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end
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# create the slot lazily, so to_mom gets called first
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def check_slot(compiler , false_label)
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Mom::TruthCheck.new(@condition.to_slot(compiler) , false_label)
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end
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def each(&block)
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block.call(condition)
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@if_true.each(&block) if @if_true
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@if_false.each(&block) if @if_false
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end
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def has_false?
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@if_false != nil
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end
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def has_true?
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@if_true != nil
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end
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def to_s(depth = 0)
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parts = "if (#{@condition.to_s(0)})\n"
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parts += " #{@if_true}\n" if @if_true
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parts += "else\n" if(@false)
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parts += " #{@if_false}\n" if(@false)
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parts += "end\n"
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at_depth(depth , parts )
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end
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end
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end
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