Drew Lazzeri (Mar 07 2024 at 20:37): Drew Lazzeri (Mar 07 2024 at 20:37):I am running into a strange type error with a recursive function. I made a Minimum Reproducible Example here, with more context: https://github.com/roc-lang/roc/issues/6563
Drew Lazzeri (Mar 07 2024 at 20:38):The error is strange: Value is: "Int a" ... needs to be ... "Int a"
Drew Lazzeri (Mar 07 2024 at 20:38):I'm doing some recursion and some high level function passing too here - maybe it's a lambda set problem?
Richard Feldman (Mar 07 2024 at 22:05):seems likely! @Ayaz Hafiz I know you're busy, but I'd like to look into this - any tips on how to use checkmate to debug something like this?
Ayaz Hafiz (Mar 08 2024 at 02:53):you could use checkmate; the documentation for it is here: https://roc.zulipchat.com/#narrow/stream/395097-compiler-development/topic/checkmate/near/380910750 and https://github.com/roc-lang/roc/blob/7d51d2b000c6de6aad647b4889ebb9e4c716cf7b/crates/compiler/checkmate/README.md#L1-L5
I would suggest trying this without type annotations first though. Does that work?
Drew Lazzeri (Mar 09 2024 at 02:09):Running without type annotations does work! Wonderful! I've added that suggestion to the gh issue, but I didn't see any tags that seemed relevant to make this findable later. Any suggestions?
Kiryl Dziamura (Mar 09 2024 at 07:03):I would assume that it's lambdasets problem which is caused by different types generated for the generic Int a. I encountered a very similar problem that was solved by removing the annotation, but can’t find if I reported it.
Last updated: Jul 26 2025 at 12:14 UTC