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So true. The thing that put me on the path of discovering parsers was a tweet that said something to the effect of “if you want any relatively complex regex, wh

by seer 6y ago

So true. The thing that put me on the path of discovering parsers was a tweet that said something to the effect of “if you want any relatively complex regex, what you actually need is a recursive descent parser”. Now as a self thought dev I haven’t really been shown in school what those were and always thought of them as some wizardly magic that only compiler writers dabble in. But after that tweet I looked around and discovered https://github.com/dmaevsky/rd-parse https://github.com/dmaevsky/rd-parse which is a 100-ish line library, and using it you can do https://github.com/dmaevsky/rd-parse-jsexpr/blob/master/src/grammar.js https://github.com/dmaevsky/rd-parse-jsexpr/blob/master/src/... which is a 200-ish lib that parses all of freakin JS expression syntax. Now whenever we have various custom unwieldy regexes to parse some input, I can refactor that into a clean and easily understandable parser. I guess thats why you need at least a little bit of formal education in CS.

richeyryan 6y ago
I once worked on a product where the idea was the end user would write a lot of custom regexes to parse the output of commands on network devices. The system was written in such a way that the regexes were nested and looped depending on the depth of the output. The overall result is you could read and update config on a device based on what output of these regexes. It seemed bizarre to me that it was considered an appropriate solution. The end users were network engineers so they were _able_ to write the regexes but it seemed obvious to me that providing the user with a higher level parsing library would be much easier. It was something I wanted to POC but never found time in the end.
brundolf 6y ago
I have a CS degree but we just never really covered parsing or compiling at all, for whatever reason (well... technically we talked about the formal theory behind grammars a little bit but we never did anything with it, and it hasn't really been useful at all) But I always dreamed of making a programming language so one of my pandemic projects was to read Crafting Interpreters, and ever since then I've been a little bit obsessed That's a great point about regexes! I'll have to keep that one in mind

by seer 6y ago

richeyryan 6y ago

I once worked on a product where the idea was the end user would write a lot of custom regexes to parse the output of commands on network devices. The system was written in such a way that the regexes were nested and looped depending on the depth of the output. The overall result is you could read and update config on a device based on what output of these regexes. It seemed bizarre to me that it was considered an appropriate solution. The end users were network engineers so they were _able_ to write the regexes but it seemed obvious to me that providing the user with a higher level parsing library would be much easier. It was something I wanted to POC but never found time in the end.

brundolf 6y ago

I have a CS degree but we just never really covered parsing or compiling at all, for whatever reason (well... technically we talked about the formal theory behind grammars a little bit but we never did anything with it, and it hasn't really been useful at all) But I always dreamed of making a programming language so one of my pandemic projects was to read Crafting Interpreters, and ever since then I've been a little bit obsessed That's a great point about regexes! I'll have to keep that one in mind