# A Frame is set up by functions that use local variables or temporary variables # in fact temporary variables are local variables named by the system # It allows for access to those variables basically # A Message and a Frame make up the two sides of message passing: # A Message (see details there) is created by the sender and control is transferred # A Frame is created by the receiver # In static languages these two objects are one, because the method is known at compile time. # In that case the whole frame is usually on the stack, for leaves even omitted and all data is # held in registers # # In a dynamic language the method is dynamically resolved, and so the size of the frame is not # know to the caller # Also exceptions (with the possibility of retry) and the idea of being able to take and store # bindings make it, to say the very least, unsensibly tricky to store them on the stack. So we don't. # Also at runtime Messages and Frames remain completely "normal" objects. Ie have layouts and so on. # Which resolves the dichotomy of objects on the stack or heap. Sama sama. module Parfait class Frame < Object def initialize locals , temps super() @locals = locals @tmps = tmps end attr_accessor :locals , :tmps end end