[bluelightning2k]

This is very, very, very cool.

I implemented something like this once but had to use the typescript compiler to identify all the variable names and also use the typescript compiler to find valid moments they could change and insert code to capture their value at that time. Guessing you didn't go to that length in multiple languages. Sou how did you manage this? I'd be very interested in a technical write up and I suspect hn would too

[anougaret]

Will def. do a technical write up! Wanted to do a more target approach like you around valid mutations only but I think users want to observe variables not only where they are written but also where they are read, so a low hanging fruit was to wrap all the expressions I could (hundreds of lines of AST queries and tricks per language) with functions/lambdas and some sort of "logging". Of course this is only 4 weeks in the making so there is so much more to do. And as you guessed you probably can't do the targeted approach well in Python and others.