rubyx/lib/vool/if_statement.rb
Torsten Rüger c43436f35a Change Mom to SlotMachine
rather large commit, but essentially a simple rename
Rationale in docs and blogs
2019-10-03 20:55:41 +03:00

62 lines
1.7 KiB
Ruby

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