- Simon Peyton Jones's "The implementation of functional programming languages" has a chapter on the "Efficient compilation of pattern matching" (chapter 5 by Philip Wadler).
https://simon.peytonjones.org/assets/pdfs/slpj-book-1987-2up...
- Also Xavier Leroy's ZINC paper (https://xavierleroy.org/bibrefs/Leroy-ZINC.html) although I believe that's no longer the implementation used by OCaml since it got replaced by an even more efficient one.
- Probably Compiling Pattern Matching to Good Decision Trees (by Luc Maranget) is the scheme used by OCaml (http://moscova.inria.fr/%7Emaranget/papers/ml05e-maranget.pd...).
It explains how to minimize the decisions trees you obtain from a match statement, so you gain a ton of efficiency over a naive implementation, especially for large, multi-column matches.
- As someone who has implemented full match in several industrial languages: this isn’t really match; it doesn’t not handle unpacking. And that is by far the only interesting bit. This feature is more accurately called `cond` à la Scheme, and you can fully expand it away ahead of type checking. Looking at unpacking in the arms, even with Scheme’s truth-y values and `=>`, could be neat.
Optimizing well-known jumps is useful, as is branch reordering, but the tombstone flag is unnecessary; you can simply write down a list of all targeted / called blocks and perform dead block elimination more generally that way.
- Golang is a blub language, so not really surprising.
