Taus 957c89b478 yeast: Support multi-phase desugaring via DesugaringConfig::add_phase ...

Extend the desugaring config from a single flat list of rules to an
ordered sequence of named Phases. Each phase runs to completion (a
full traversal applying its rules) before the next phase starts.
Rules in different phases never compete for matches.

The config is built via the new chainable API:

    DesugaringConfig::new()
        .add_phase("cleanup", cleanup_rules)
        .add_phase("desugar", desugar_rules)
        .with_output_node_types_yaml(yaml);

Single-phase configs are just .add_phase(...) called once.

A single FreshScope is shared across phases so generated identifier
names (e.g. $tmp-N) are unique throughout the run.

Phase names appear in error messages, e.g. "Phase `desugar`:
exceeded maximum rewrite depth".

Add two regression tests: one verifying basic two-phase chained
desugaring, and one verifying that errors include the failing phase
name.

2026-05-06 21:17:31 +00:00

..

node-types.yml

yeast: Add test for chained rules with output-only kinds

2026-05-06 11:45:53 +00:00

test.rs

yeast: Support multi-phase desugaring via DesugaringConfig::add_phase

2026-05-06 21:17:31 +00:00