rubyx/lib/slot_machine/instruction/resolve_method.rb

74 lines
2.1 KiB
Ruby

module SlotMachine
# Dynamic method resolution is at the heart of a dynamic language, and here
# is the SlotMachine level instruction to do it.
#
# When the static type can not be determined a CacheEntry is used to store
# type and method of the resolved method. The CacheEntry is shared with
# DynamicCall instruction who is responsible for calling the method in the entry.
#
# This instruction resolves the method, in case the types don't match (and
# at least on first encouter)
#
# This used to be a method, but we don't really need the method setup etc
#
class ResolveMethod < Instruction
attr :cache_entry , :name
# pass in source (SolStatement)
# name of the method (don't knwow the actaual method)
# and the cache_entry
def initialize(source , name , cache_entry)
super(source)
@name = name
@cache_entry = cache_entry
end
def to_s
"ResolveMethod #{name}"
end
# When the method is resolved, a cache_entry is used to hold the result.
# That cache_entry (holding type and method) is checked before, and
# needs to be updated by this instruction.
#
# We use the type stored in the cache_entry to check the methods if any of it's
# names are the same as the given @name
#
# currently a fail results in sys exit
def to_risc( compiler )
name_ = @name
cache_entry_ = @cache_entry
builder = compiler.builder(self)
builder.build do
word! << name_
cache_entry! << cache_entry_
type! << cache_entry[:cached_type]
callable_method! << type[:methods]
add_code while_start_label
object! << Parfait.object_space.nil_object
object - callable_method
if_zero exit_label
name! << callable_method[:name]
name - word
if_zero ok_label
callable_method << callable_method[:next_callable]
branch while_start_label
add_code exit_label
MethodMissing.new(compiler.source_name , word.symbol).to_risc(compiler)
add_code ok_label
cache_entry[:cached_method] << callable_method
end
end
end
end