One of the subtle things hidden in your statement (which I do somewhat agree with) is “sane language”. One of the more memorable parsers I’ve worked on was a p

One of the subtle things hidden in your statement (which I do somewhat agree with) is “sane language”. One of the more memorable parsers I’ve worked on was a parser for SPICE netlists. I started out believing that it wasn’t going to be too big of a deal, and ended up sinking a ton of time into it. Ultimately the company (as far as I know) ended up just buying a $40k license to some obscure company that had one, because there was a constant cat-and-mouse game of getting it working right and then discovering a customer who did even more strange stuff that was somehow accepted by the 3rd-party SPICE sim, but wouldn’t be accepted by ours. I’m assuming that PHP has evolved a ton since I encountered this, but IIRC at one point you couldn’t do `$foo[$baz]($zap)` to call an anonymous function stored in an array, rather you had to `$t = $foo[$baz]; $t($zap)`. At the time (young and naive), I just couldn’t comprehend how a sane parser wouldn’t parse the first form, and then I started looking at how it was implemented...