Module rules 

Matching the rewrite rules against the IR.

Design: spec/optimizer/13-rewrite-rules.md. The rules themselves are in rules/, one file per tier, and the automaton they compile into is generated by rucc-rules when this crate is built. What each rule means is crates/rucc-ir/rules/ir.model, and rucc-verify makes every one of them prove itself against that model before it may be used.

The walk over the automaton is rucc_base::rules, which is where it is because rucc-codegen matches its lowering rules with the same walk and neither crate can see the other. What an IR instruction looks like to that walk is rucc_ir::term, for the same reason: a rewrite rule and a lowering rule that spelled add.i32 differently would be two vocabularies over one IR.

The names are re-exported rather than reached for through rucc_base, because the generated file refers to them through super and that is the whole of the contract between the two.

Modules

canonical

The tier three rewrite table.

identities

The tier one rewrite table.

strength

The tier two rewrite table.

Structs

Match

What a successful match found.

Node

One node of the trie over the patterns.

Rule

One rule, as much of it as matching needs.

Table

A set of rules, as an automaton over their patterns.

Enums

Piece

One piece of a replacement, in the pre-order that builds it.

Test

One test on one subterm.

Traits

Subject

The bits of a term the automaton asks about.

Type Aliases

Guard

A condition on the constants a pattern matched.