Incorrect parsing of declarations
GHC's parser seems to accept incorrect Haskell programs, which leads to very confusing error messages. Here is an example:
f x = T
g 1 = 10
g x
data T = T
When trying to compile this GHC reports:
test.hs:1:6: Not in scope: data constructor `T'
This happened in much larger module, where I had forgotten to complete one of the equations for a function, but ended up looking for what is wrong with the (completely unrelated) "data" declaration.
This might be related to Template Haskell because a smaller example---a file containing only the literal 1---results in complaints about some template Haskell type not being in the Num class.
I am compiling the module without any pragmas or flags, so I would not think that TH is enabled.
Trac metadata
Trac field | Value |
---|---|
Version | 6.12.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler (Parser) |
Test case | |
Differential revisions | |
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Blocking | |
CC | |
Operating system | |
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