rubyx/lib/slot_machine/instruction/truth_check.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

37 lines
1.0 KiB
Ruby

module Mom
# The funny thing about the ruby truth is that it is anything but false or nil
#
# To implement the normal ruby logic, we check for false or nil and jump
# to the false branch. true_block follows implicitly
#
class TruthCheck < Check
attr_reader :condition
def initialize(condition , false_jump)
super(false_jump)
@condition = condition
raise "condition must be slot_definition #{condition}" unless condition.is_a?(SlotDefinition)
end
def to_s
"TruthCheck #{@condition} -> #{false_jump}"
end
def to_risc(compiler)
false_label = @false_jump.risc_label(compiler)
builder = compiler.builder("TruthCheck")
condition_reg = @condition.to_register(compiler,self)
builder.build do
object! << Parfait.object_space.false_object
object.op :- , condition_reg
if_zero false_label
object << Parfait.object_space.nil_object
object.op :- , condition_reg
if_zero false_label
end
end
end
end