Restore Line After Method Call Property

If LW Python has finished executing a method body, then return to the call site.

if the following are true:

  • the line at time t = i
  • the tab at time t = j
  • statement at line i, tab k = s
  • k < j
  • value at (j - 1) in map (Control Map at time t) = pair ("method", mname)
  • stack at time t = [ program context with variables: varis and expression state: (expression state with parent stack: parent_stack arguments: arg_stack values: value_stack line: line tab: tab) and control map: control_map, rest ]

then the line at time (t + 1) = line

After a method body has completed, LW Python jumps back to the line where the method call was made and resumes execution. The line number was saved in the "Stack" before jumping to the method. For example,

if the following are true:

  • the line at time 50 = 6
  • the tab at time 50 = 2
  • statement at line 6, tab 1 = def age_in_months(self):
  • value at (2 - 1) in map (Control Map at time 50) = pair ("method", "__init__")
  • stack at time 50 = [ program context with variables: [ ] and expression state: (expression state with parent stack: [ ] arguments: [ ] values: [ ] line: 8 tab: 0) and control map: [ entry 0: (pair ("class", "Person")), [ ] ], [ ] ]

then the line at time (50 + 1) = 8

Try stepping through the simulator to see LW Python jump back to the constructor call after the method is completed.

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LW Python State
Current Line1Current Tab0Time0
LW Python Simulator

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