Brummel
438a009b83
First of two plans for spec iteration mir.1 (docs/specs/0060-typed-mir.md).
mir.1 is the project's largest iteration — a full codegen frontend
switch from walking &Term to walking &MTerm — and it does not fit one
bite-sized plan, because the switch is atomic: there is no compiling
intermediate between "all Term" and "all MTerm" (dual-path is
spec-forbidden). The MIR *producer* side, by contrast, compiles and
tests in isolation. So mir.1 is sequenced across two plans:
- mir.1a (this plan): the additive producer — new leaf crate
ailang-mir (MTerm/MArg/Callee/Mode/StrRep, structurally complete over
all 17 Term variants plus the Str split), ailang-check::lower_to_mir
(post-mono walk that calls canonical synth per node and maintains
locals/loop_stack exactly as synth does — no second type engine), and
ailang-check::elaborate_workspace (check → desugar+lift → mono →
lower_to_mir). Nothing consumes MIR yet; codegen untouched; whole
suite stays green; three ty-fill pins load the #51/#53/#49 witnesses
as fixtures and elaborate the full workspace (prelude included).
- mir.1b (next plan, against the landed types): flip codegen's walk to
&MTerm, delete synth_with_extras + synth_arg_type (9 call sites across
lib.rs/drop.rs/match_lower.rs), thread the 18 lower_workspace* callers,
switch the CLI build path to elaborate_workspace.
Both together satisfy the spec's mir.1 row. The split is plan
granularity, not a spec change — the spec's mir.1 deliverable is
unchanged.
Orchestrator design calls baked in (planner judgement, no user fork):
dedicated MTerm::Str{lit,rep} variant (Str-split installs the mir.4
hook at the #49 loop seed); emit_ir keeps &Module (builds MIR
internally — minimal blast radius); lower_to_mir scaffolding mirrors
mono.rs:771-816; Match-arm binding reuses synth's own type_check_pattern.
Recon (plan-recon) mapped the full deletion blast radius for mir.1b
(9 synth_arg_type sites, not the 3 the focus-hint assumed; 18
lower_workspace* callers). The two new witness fixtures
(new_rawbuf_size_only, new_counter_user_adt) were verified ail
check-clean during planning.