#9250: let makes function too much specific ------------------------------------------------+-------------------------- Reporter: KommuSoft | Owner: Type: bug | Status: new Priority: low | Milestone: Component: Compiler | Version: 7.6.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: x86_64 Type of failure: Incorrect result at runtime | (amd64) Test Case: | Difficulty: Blocking: | Unknown | Blocked By: | Related Tickets: ------------------------------------------------+-------------------------- Description changed by KommuSoft: Old description:

Say you define a `myadd` function:

let myadd x y = x + y

Then the type is `Num a => a -> a -> a`. If on the other hand, you define the method using currying:

let myadd2 \x -> \y -> x + y

The type is more specific: `Integer -> Integer -> Integer`. Strangely enough `:t \x -> \y -> x + y` returns the more general form.

New description: Say you define a `myadd` function: let myadd x y = x + y Then the type is `Num a => a -> a -> a`. If on the other hand, you define the method using currying: let myadd2 \x -> \y -> x + y The type is more specific: `Integer -> Integer -> Integer`. Strangely enough `:t \x -> \y -> x + y` returns the more general form. URL: http://stackoverflow.com/questions/24481024/why-does-currying- anonymous-functions-change-haskells-type-inference-from-num-t -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9250#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler