Misleading error when custom type names partially overlap

[ngua]

It seems that if custom type names partially overlap, using moduleQuoter with the custom types throws a very misleading error

I discovered this while trying to add a modelName type to the inferno-ml Prelude. I first tried:

customTypes :: [CustomType]
customTypes = ["tensor", "model", "modelName", "write"]

As you can see, modelName follows model. Then, I tried adding the following to mlQuoter (i.e moduleQuoter customTypes):

  ...

  loadModel : modelName -> model := ###!loadModelFun###;

This led to the following compile-time exception:

src/Inferno/ML/Module/Prelude.hs:192:13: error:
    • Error at line 252 column 3
        unexpected 'l'
        expecting one of the following:
        ∙ "module"
        ∙ end of input

    • In the quasi-quotation:
        [mlQuoter|
...

The error message misleadingly implies that there is a parse error; however, the problem is that modelName follows model, I assume this leads to some ambiguity. Changing the order of the customTypes to [..., "modelName", "model", ...] resolved the error, although this was very difficult to debug!