karel-for-synthesis 1.4.0

Karel Parser and Executor useful for program synthesis.

Karel For Synthesis

Parser and executor for Karel. Based almost entirely on Nearai's code with some modifications.

Usage

To use the executor, run

from karel_for_synthesis import execute

result = execute(program, input_grid, record_trace=True)

You can also parse and unparse programs by using the parse and unparse commands.

Outputs

This will give you an ExecutionResult object, with the following structure

• ExecutionResult
  • .result: the output grid, or None if there was an error
  • .trace: the output trace. None if record_trace=False is passed
    • .grids: the grids at every timestep in the execution of the program
    • .events: a series of KarelEvent objects
      • .timestep: grids[timestep] corresponds to the grid after this timestep
      • type: the token being executed
      • span: (i, j) for the first and last tokens corresponding to this block
      • cond_span: (i, j) for the first and last tokens contained in the conditional expression if one exists or None otherwise
      • cond_value: the value of the conditional expression or number of remaining iterations
      • success: False if the action failed or the loop repeats forever

Errors

• ExecutorSyntaxException: occurs if the program passed in has invalid syntax
• ExecutorRuntimeException: occurs if the program passed in has an error in executing and record_trace=False is passed