picotron error explorer

by kira

version 0.0.6

an interactive error screen for picotron. on error, shows the stack, local variables, and the source code when available.

usage

include or require error_explorer.lua in your program after defining your _init, _update, and _draw functions.

press up and down to move up and down on the stack, press x or space to toggle font size. click on tables in the variable view to expand them.

how it works

in order to catch errors and inspect runtime state, this script replaces _init, _update and _draw functions with ones that call the original ones inside a coroutine.

when there's an error, it uses lua's debug library to inspect the coroutine. a copy of the error is also printed to the console with printh if you're running picotron from the command line.

the following debug apis are used:

• debug.getinfo
• debug.getlocal
• debug.getupvalue
• debug.traceback

version history

version 0.0.6

• on error:
  • show cursor
  • make window resizable
• automatically adjust layout to window size
• support yielding (since fetch sometimes yields)

version 0.0.5

• future proofing: gracefully handle when various parts of the debug module aren't available

version 0.0.4

• also catch errors in _init

version 0.0.3

• automatically choose the right stack frame based on the error message
• more thoroughly protect from errors in error explorer itself

version 0.0.2

• don't regenerate stack info every draw
• scroll stack and variables list with mousewheel
• click on stack to switch stack frames
• click on tables in variables view to expand them
• escape strings when printing them

version 0.0.1

• adjust colors
• code cleanup
• use btnp instead of keyp
• slightly more thorough reset
• don't show temporaries

version 0.0.0 (prerelease)

• initial discord beta