erlang: replace unbound vars in specs with wildcards (_) (fixes #20)
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| when List.length (List.find_all (( = ) n) occurs) < 2 -> | ||
| Type_variable (Var_name "_") |
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This is the main logic. Probably, it's worth to extract the condition into a separate function something like is_var_unbound?
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Makes sense, we can do this small refactors later on.
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Thanks for this! It should make it easier to work with type variables going forward 😄 (Merging it now before I start doing more changes to the Erlang Parsetree and it bitrots) |
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Fixes #20
Change
Rolling back e916333. + Changing the logic of handling type variables in specs:
If a generated/translated spec has a type variable which is used exactly once (
erl_lintcalls such variables "unbound variables"), such a variable is replaced with the wildcard type variable (_). This makeserlc/erl_linthappy about generated code.Snapshot tests are updated accordingly.
Subtlety
This new logic doesn't try to distinguish "original" (but also unbound for
erlc) OCaml type variables and inferred type variables: if a type variable is unbound it will be replaced by_anyway.This makes this example less idiomatic:
Before:
After:
Possible improvement(s)
_, eg the unbound type variable_Xis totally fine forerl_lintand falls into the category "I don't care".where_is) and to not replace them with_.erlang/src/erl_ast_helper.ml- I did not read many parts of the project in detail, - so my code is likely not of the same style as the rest of the project.Thanks for a really cool and interesting project!