asai: a Library for Compiler Diagnostics

on YouTube ↗33m

" summary

asai is an OCaml library that generates structured and partly‑unstructured compiler diagnostics, using algebraic effects to build semantic, user‑level backtraces and supporting multi‑span highlights instead of single column offsets. it avoids visual Unicode width heuristics (publishes byte/UTF‑16 offsets for LSP), emits Googleable error codes, and composes across libraries. a working prototype exists, it renders to terminal and HTML backends, and has been adopted to generate a website and to drive a private type‑checker under development.

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" chapters (13)

1. 0:00Asai introduction
2. 1:04Designing compiler diagnostics
3. 5:05User-friendly features
4. 7:14Structured vs unstructured errors
5. 10:28Compositionality in design
6. 11:54Unicode challenges
7. 18:20Tutorial API design
8. 19:24Comparison with Grace
9. 21:09Success stories
10. 22:33Live demo
11. 27:12Demo results
12. 28:58Interaction with monads
13. 29:19Q&A

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