[0] https://github.com/lourencovales/codecrafters/blob/master/sh...
I have seen this misconception many times
In Oils, we have some pretty minor elaborations of the standard model, and it makes things a lot easier
How to Parse Shell Like a Programming Language - https://www.oilshell.org/blog/2019/02/07.html
Everything I wrote there still holds, although that post could use some minor updates (and OSH is the most bash-compatible shell, and more POSIX-compatible than /bin/sh on Debian - e.g. https://pages.oils.pub/spec-compat/2025-11-02/renamed-tmp/sp... )
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To summarize that, I'd say that doing as much work as possible in the lexer, with regular languages and "lexer modes", drastically reduces the complexity of writing a shell parser
And it's not just one parser -- shell actually has 5 to 15 different parsers, depending on how you count
I often show this file to make that point: https://oils.pub/release/0.37.0/pub/src-tree.wwz/_gen/_tmp/m...
(linked from https://oils.pub/release/0.37.0/quality.html)
Fine-grained heterogenous algebraic data types also help. Shells in C tend to use a homogeneous command* and word* kind of representation
https://oils.pub/release/0.37.0/pub/src-tree.wwz/frontend/sy... (~700 lines of type definitions)
For side-projects, I have to ask myself if I'm writing a parser, or if I'm building something else; e.g. for a toy programming language, it's way more fun to start with an AST and play around, and come back to the parser if you really fall in love with it.