Second half of spec iteration mir.1, planned against the landed mir.1a
infrastructure (135f4ce). This is the project's largest single
mechanical change and it is atomic: codegen's entire lowering walk
flips from &Term to &MTerm with no compiling intermediate (dual-path is
spec-forbidden). plan-recon proved the blast radius with a compile stub
(flipping only lower_term's signature → 58 cascading errors across
lib.rs/drop.rs/match_lower.rs/escape.rs/lambda.rs, baseline restored
green). The plan gives a Term→MTerm correspondence rule for the
mechanical arm renames (the build gate is the totality checker), exact
before→after for the judgement sites (the 9 synth_arg_type reads → ty(),
the dual-source Emitter, escape pointer-identity, entry-point
signatures, CLI diagnostics), and a satisfiable gate per task.
Four recon open-questions resolved by orchestrator judgement (within
the approved spec's intent; the spec's MirModule sketch is illustrative
and exact shape is the planner's):
- OQ1: MirModule gains `ast: Module` — codegen reads structural data
(Type/Const/ctor/intrinsic markers/symbol tables) from .ast, typed fn
bodies from .defs. MirWorkspace stays the single artefact (it now
contains the post-mono AST); structural reads were never a
re-derivation, so this does not reintroduce one. Also resolves the
intrinsic-fn gap (lower_module skips intrinsic bodies; codegen
iterates ast.defs and looks up MirDef bodies by name).
- OQ2: emit_fn borrows mir_def.body:&MTerm once and shares it between
escape::analyze_fn_body and lower_term (pointer identity is only
stable within one borrowed tree); casts flip to *const MTerm.
- OQ3: MTerm::New's codegen arm stays unreachable! — New is desugared
away before codegen (RawBuf→payload, monomorphic user-ADT new→dotted
App), exactly as Term::New is today; #51 builds unchanged.
- OQ4: the CLI build/emit-ir paths drop their separate check_workspace
call and let elaborate_workspace's Err drive diagnostics (one check,
not two); `ail check` stays on check_workspace.
- emit_ir keeps &Module, calls elaborate_workspace internally,
converts Err(diags)→CodegenError; its builtin-only in-source tests
check clean without a prelude.
Task structure: Task 1 (additive) extends MirModule + populates ast +
adds codegen's ailang-mir dep, gate cargo test --workspace. Task 2 (the
atomic flip) converts the whole codegen crate including its tests, gate
cargo test -p ailang-codegen (deliberately excludes crates/ail so the
not-yet-threaded external callers don't fail this gate). Task 3 threads
the crates/ail callers (CLI build/emit-ir/staticlib + 6 e2e callers),
gate cargo test --workspace == 102 ok (the mir.1a baseline), #51/#53
build+run, synth_with_extras/synth_arg_type grep-clean.
refs #49
Brummel
1a1a68df8b