Fancy assert block

I made an assert block that uses SPLIT BY BLOCKS to tell you what the predicate's arguments were if the assertion fails. It also has a label slot for arbitrary text that's displayed as part of the error message, to help you find where in the script the error occurred.


For now the predicate's arguments can be numbers, texts, Booleans, or lists thereof (which will be stringified in a Lisp-like notation)

Nice. I was a little sad when I realized that you use, e.g., LHS and RHS as the input labels for all dyadic blocks. I guess for primitives the alternative would be to have a table of all of them with appropriate labels. But for custom blocks you should be able to extract the formal parameters from the block.

Oh thanks that's a neat idea! Is there a simpler way to get the names of the parameters that I'm just missing? The only way I found seems a bit overcomplicated:

  • split the block definition by blocks
  • if the definition only contains one command block, the last n items of that list are its parameter names (where n is the number of parameters)
  • if it contains more than one, the parameter names are the last n items of the first item of that list

fancy assert block script pic

(the parameter names are at 1F and 1G in the second example)

Yeah, that does seem complicated. Lemme ask Jens about it...