feat(codegen): thread imported TopConst across module boundaries (closes #107)#109
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#107) Closes #107. Before this commit, `Codegen.gen_imports` and `Module_loader.flatten_imports` both pattern-matched only `TopFn` in the imported module's `prog_decls`, silently dropping public `TopConst` items. A `use M::{some_const}` that the typechecker accepted would then fail at WASM codegen with `Codegen.UnboundVariable some_const`. ## Changes ### `lib/codegen.ml` — `gen_imports` - Match `TopFn` and `TopConst` in declaration order; first match wins (same-name fn+const in one module would be a resolver error). - For an imported `TopFn`: unchanged (emits the WASM `(import "<mod>" "<fn>" ...)` and registers the positive function index). - For an imported `TopConst`: compile the initialiser against the importer's context via `gen_expr`, append a fresh global, register `(local_name, -(global_idx + 1))` in `func_indices` — same negative-sentinel encoding as locally-declared consts, so use-site lookup is uniform. - Glob expansion (`use M::*`) likewise includes public consts. WASM module-linking for globals isn't standard yet, so the const value is inlined per importer. Identity is by value, which matches AffineScript's immutability guarantee. ### `lib/module_loader.ml` — `flatten_imports` - Local-decl name suppression set now covers fns AND consts. - Public consts get inlined into the importer's `prog_decls` alongside public fns, with the same alias-renaming machinery for `use M::{c as d}`. - Non-WASM back-ends (Rust, JS, OCaml, Lua, …) see imported consts as if they were locally declared, so they inherit the fix without per-target changes. ### Tests — `test/test_e2e.ml` Two regression tests in the `E2E Xmod Other Codegens` group: - `flatten_imports inlines imported public consts (#107)` — parses `cross_const_caller.affine`, runs the loader, asserts the imported `input_marker` const and `marker_plus` fn both appear in the flattened `prog_decls`. - `WASM gen_imports threads imported consts (#107)` — compiles `PortNames.affine` then `cross_const_caller.affine`; asserts the caller emits at least one global initialised to the const's value (256). The earlier failure mode would have errored out at `compile_fixture_to_wasm` before the assertion. Two new fixtures: - `test/e2e/fixtures/PortNames.affine` — exports `pub const input_marker` + a fn that uses it. - `test/e2e/fixtures/cross_const_caller.affine` — imports and uses both. ### Docs - `docs/specs/SPEC.adoc` §8.4 — drops the "do not yet flow" bullet for consts; the cross-module flow table now lists const-as-inlined-value as supported. - `docs/specs/codegen-environment.adoc` §5 — split into 5.1 (TopFn), 5.2 (TopConst inlining algorithm + identity-by-value note), 5.3 (glob expansion). §10 records #107 as closed and points at the regression tests. ## Inline-record-escape note `TopConst` is declared with an inline record. The OCaml compiler rejects `| TopConst tc when ...` followed by using `tc` as a value ("the type of the inlined record could escape"), so the match destructures the needed fields directly: `| TopConst { tc_name; tc_value; _ } when tc_name.name = orig_name -> Some (`Const tc_value)`. The glob path destructures `{ tc_vis; tc_name; _ }`. Reconstruction in the alias-rename path uses inline-literal construction, which is allowed.
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Closes #107.
Threads imported
TopConstitems through both code paths that previously dropped them, souse M::{some_const}now compiles end-to-end instead of failing at codegen withUnboundVariable.Implementation
Codegen.gen_imports— matchesTopFnandTopConsttogether. Imported consts: compile the initialiser inline against the importer's context, append a fresh global, register(local_name, -(global_idx + 1))infunc_indices(same negative-sentinel encoding as locally-declared consts, so use-site lookup is uniform).Module_loader.flatten_imports— local-decl name suppression now covers fns and consts; public consts flow through the same alias-rename and dedup pipeline as fns, so all non-WASM back-ends pick up the fix unchanged.WASM module-linking for globals isn't standard yet, so cross-module const identity is by value — each importer materialises its own copy of the constant. Fine because AffineScript consts are immutable.
Tests
E2E Xmod Other Codegensgains two cases (#107 regression):flatten_imports inlines imported public consts— non-WASM path, asserts the imported const appears inprog_declsafter flattening.WASM gen_imports threads imported consts— full compile path, asserts the caller emits a global initialised to the imported const's value. The prior failure mode would have errored atcompile_fixture_to_wasmitself.Two new fixtures:
PortNames.affine(exportspub const input_marker),cross_const_caller.affine(imports + uses it).Spec updates
SPEC.adoc§8.4 — drops the "do not yet flow" bullet; cross-module flow now lists const-as-inlined-value as supported.codegen-environment.adoc§5 — split into 5.1 (TopFn), 5.2 (TopConst inlining algorithm + identity-by-value note), 5.3 (glob expansion). §10 records Cross-module imports: TopConst not threaded by gen_imports / flatten_imports #107 as closed.Inline-record-escape note
TopConstis an inline-record constructor. Capturing the whole record as a variable triggers OCaml's "type of the inlined record could escape" error. The match instead destructures the needed fields directly:| TopConst { tc_name; tc_value; _ } when tc_name.name = orig_name -> Some (\Const tc_value)`. The alias-rename path reconstructs by inline-literal — that form is allowed.Test plan
dune build lib bin testclean.E2E Xmod Other Codegens— all 4 tests pass (2 pre-existing + 2 new).dune runtestclean on CI.