fix(eval): error on silent rebinding in the same scope #24

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opened 2026-07-02 14:03:37 +00:00 by toph · 0 comments

toph commented

2026-07-02 14:03:37 +00:00

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Currently --x = … twice, or rebinding a corner .a, silently replaces the binding (Hashtbl.replace in eval.ml:254,294). The step/macro design justifies = with "constructions are immutable, so there is no reassignment case" — the implementation contradicts that, and spec §8 lists no duplicate-binding error.

Make duplicate binding in the same scope an error. When the step slice lands, the same rule must hold across every export form: export-all and inline validate each landed name exactly like selective export, and ! applies per name in all forms. A shadowing marker that only guards the narrow path is worse than none — readers will trust an invariant that doesn't hold.

Currently `--x = …` twice, or rebinding a corner `.a`, silently replaces the binding (`Hashtbl.replace` in `eval.ml:254,294`). The step/macro design justifies `=` with "constructions are immutable, so there is no reassignment case" — the implementation contradicts that, and spec §8 lists no duplicate-binding error. Make duplicate binding in the same scope an error. When the step slice lands, the same rule must hold across every export form: export-all and `inline` validate each landed name exactly like selective export, and `!` applies per name in all forms. A shadowing marker that only guards the narrow path is worse than none — readers will trust an invariant that doesn't hold.

toph referenced this issue

2026-07-02 14:03:39 +00:00

design: rewrite the step/macro spec against the real grammar #29

toph referenced this issue from a commit

2026-07-03 00:28:02 +00:00

feat(eval): error on silent rebinding; _-temps rebind and stay unnamed (#24)

toph referenced this issue from a pull request that will close it,

2026-07-03 00:29:15 +00:00

feat: def/apply/export/step — reusable folding sequences, instances, panels #35

toph closed this issue

2026-07-03 00:39:23 +00:00