rubyx/lib/ast/function_expression.rb

72 lines
2.2 KiB
Ruby

module Ast
class FunctionExpression < Expression
attr_reader :name, :params, :body , :receiver
def initialize name, params, body , receiver = nil
@name = name.to_sym
@params = params
@body = body
@receiver = receiver
end
def attributes
[:name, :params, :body , :receiver]
end
def inspect
self.class.name + ".new(" + name.inspect + ", ["+
params.collect{|m| m.inspect }.join( ",") +"] , [" +
body.collect{|m| m.inspect }.join( ",") +"] ,"+ receiver.inspect + " )"
end
def to_s
ret = "def "
ret += "#{receiver}." if receiver
ret + "#{name}( " + params.join(",") + ") \n" + body.join("\n") + "end\n"
end
def compile context , into
raise "function does not compile into anything #{self}" if into
args = []
locals = {}
params.each_with_index do |param , index|
arg = param.name
arg_value = Vm::Integer.new(index+1)
locals[arg] = arg_value
args << arg_value
end
# class depends on receiver
if receiver.nil?
clazz = context.current_class
else
c = context.object_space.get_or_create_class receiver.name.to_sym
clazz = c.meta_class
end
function = Vm::Function.new(name , args )
clazz.add_function function
parent_locals = context.locals
parent_function = context.function
context.locals = locals
context.function = function
into = function.body
last_compiled = nil
body.each do |b|
puts "compiling in function #{b}"
last_compiled = b.compile(context , into)
raise "alarm #{last_compiled} \n #{b}" unless last_compiled.is_a? Vm::Word
end
return_reg = Vm::Integer.new(7)
if last_compiled.is_a?(Vm::IntegerConstant) or last_compiled.is_a?(Vm::StringConstant)
return_reg.load into , last_compiled if last_compiled.register != return_reg.register
else
return_reg.move( into, last_compiled ) if last_compiled.register != return_reg.register
end
function.set_return return_reg
context.locals = parent_locals
context.function = parent_function
function
end
end
end