Push Self To Values Property

When evaluating a method call, LW Python pushes the reference to the object to "Argument Values." More formally,

if the following are true:

  • expression state at time t = "call_function_begin"
  • the expression at time t = obj_name.method_name(args)
  • value at obj_name in map (Variables Map at time t) = Python reference index
  • the element at index index of stack (Python Object Store at time t) = Python object: [ entry "__class_name__": class_name, e_rest ]
  • Value Stack at time t = [ values, v_stack ]
  • definition of method method_name of class class_name in (Class Map at time t) = method_map

then Argument Values at time (t + 1) = [ Python reference index, reverse of values ]

In a function call, "Argument Values" is just the reverse of the top of the "Values" stack. However, in a method call, "self" is always the first argument, so LW Python adds it on top. For example,

if the following are true:

  • expression state at time 56 = "call_function_begin"
  • Value Stack at time 56 = [ [ ], [ ] ]
  • the expression at time 56 = p.age_in_months()
  • value at p in map (Variables Map at time 56) = Python reference 0
  • the element at index 0 of stack (Python Object Store at time 56) = Python object: [ entry "__class_name__": "Person", [ entry "first_name": "John", [ entry "last_name": "Smith", [ entry "age": 25, [ ] ] ] ] ]
  • definition of method "age_in_months" of class "Person" in (Class Map at time 56) = [ entry "params": [ self, [ ] ], [ entry "line": 6, [ ] ] ]

then Argument Values at time (56 + 1) = [ Python reference 0, reverse of [ ] ]

Try stepping through the simulator to see LW Python populate "Argument Values."

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