Breaking Line Property

If the "break" state is "breaking" at time t, and LW Python is currently inside an "if/elif/else" block, then at time t + 1, the line number stays the same. More formally,

if the following are true:

  • the line at time t = i
  • the tab at time t = j
  • "break" state at t = "breaking"
  • value at (j - 1) in map (Control Map at time t) = control_value
  • control_value describes a loop = False

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

How do we know whether Python is currently inside an "if/elif/else" block? If the "Control" map has an entry at current tab - 1, and the value has an "if" in it, then we know that there was an "if/elif/else" statement at current tab - 1.

For example,

if the following are true:

  • the line at time 82 = 6
  • the tab at time 82 = 2
  • "break" state at 82 = "breaking"
  • value at (2 - 1) in map (Control Map at time 82) = pair ("if", True)

then the line at time (82 + 1) = 6

Try stepping through the simulator to see the "Current Line" remain at 6 while LW Python is breaking.

Code Editor
LW Python State
Current Line1Current Tab0Time0
LW Python Simulator

Comments

Please log in to add comments