Please consider supporting. This content WILL end some day, but every dollar I make pushes that day further out

Join on youtube for happy hour vods https://www.youtube.com/channel/UCXzL31BCxf8En1KT34gSK6g/join
Or on patreon https://patreon.com/sphaerophoria
Or on twitch https://twitch.tv/sphaerophoria
Or sponsor me on github (no benefits) https://github.com/sponsors/sphaerophoria

00:00 Intro
06:35 Design
10:47 Baby's first generated parser
01:26:50 Multiple characters

sphaerophoria

A live coding session building a rudimentary parser generator in Zig from scratch. The author is motivated by the tedium of hand-rolling parsers for an HTTP-like SIP protocol (specifically parsing 'Via' headers defined in ABNF/BNF). The approach: define a simple intermediate representation of BNF rules, then generate Zig source code (structs, parse functions, unions) from that IR. The session covers designing the IR for single characters, character ranges, rule references, sequences, and 'one-of' alternatives, implementing a low-level parser with buffer indexing, generating typed structs and parse functions, bootstrapping the BNF parser using its own output, and iteratively fixing compilation errors. The author explicitly avoids bottom-up parsing complexity and metaprogramming in favor of straightforward code generation.

Writing the world's worst parser generator