Parsing from first principles

on YouTube ↗01h 10m

" summary

Builds a working SQL subset parser in Elixir using parser combinators (char, satisfy, choice, many, map, sequence, token, separated_list) and a lazy combinator to handle recursion for subqueries. Demo is ~160 lines and produces an AST map for SELECT columns and FROM (identifiers or subqueries); a production version grew to ~1,500 lines. Error reporting is basic; recommends adding position tracking, a two‑pass lexer, or using NimbleParsec for performance while keeping the combinator workflow for clarity.

AI-written summary · about

" chapters (12)

1. 0:00Introduction and setup
2. 3:51Why avoid parsing fear
3. 11:52Parser combinators introduction
4. 23:11Parsing single characters
5. 33:29Building identifier parser
6. 40:12Handling whitespace and tokens
7. 44:06Parsing SQL keywords
8. 47:18Select statement structure
9. 53:20Supporting subqueries
10. 55:06Error handling challenges
11. 59:21Final impressions and lessons
12. 1:02:09Q&A and closing

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