Merge pull request #396 from BinderDavid/add-error-44432

Add error message for error GHC-44432

Author: david-christiansen

message-index/messages/GHC-44432/index.md

@@ -0,0 +1,8 @@
+---
+title: Type signature lacks an accompanying binding
+summary: A type signature was provided, but no binding was given.
+severity: error
+introduced: 9.6.1
+---
+
+If a type signature is given for a name, then that name also needs to be defined.

message-index/messages/GHC-44432/let-binding/after/MissingBinding.hs

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+module MissingBinding where
+
+fortytwo :: Integer
+fortytwo =
+  let
+    two :: Integer
+    two = 2
+  in 
+    40 + two

message-index/messages/GHC-44432/let-binding/before/MissingBinding.hs

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+module MissingBinding where
+
+fortytwo :: Integer
+fortytwo =
+  let
+    two :: Integer
+  in 
+    40 + two

message-index/messages/GHC-44432/let-binding/index.md

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+---
+title: Type signature lacks an accompanying binding
+---
+
+If a type signature is given for a name in a local let expression, then the name also needs to be defined.
+
+In this example, a type signature was given for the name `two` in a let expression, but no definition was specified.
+This error can be fixed by adding a definition which accompanies the type signature.
+
+## Error Message
+
+```
+MissingBinding.hs:6:5: error: [GHC-44432]
+    The type signature for ‘two’ lacks an accompanying binding
+  |
+6 |     two :: Integer
+  |     ^^^
+```

message-index/messages/GHC-44432/toplevel/after/MissingBinding.hs

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+module MissingBinding where
+
+someBoolean :: Bool
+someBoolean = True

message-index/messages/GHC-44432/toplevel/before/MissingBinding.hs

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+module MissingBinding where
+
+someBoolean :: Bool

message-index/messages/GHC-44432/toplevel/index.md

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+---
+title: Type signature lacks an accompanying binding
+---
+
+If a type signature is given for a name in a Haskell module, then the name also needs to be defined.
+
+In this example, a type signature was given for the name `someBoolean` in a Haskell module, but no definition was specified.
+This error can be fixed by adding a definition which accompanies the type signature.
+
+## Error Message
+
+```
+MissingBinding.hs:3:1: error: [GHC-44432]
+    The type signature for ‘someBoolean’ lacks an accompanying binding
+  |
+3 | someBoolean :: Bool
+  | ^^^^^^^^^^^
+```

message-index/messages/GHC-44432/typo/after/MissingBinding.hs

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+module MissingBinding where
+
+import Numeric.Natural
+
+factorial :: Natural -> Natural
+factorial n
+  | n == 0 = 1
+  | otherwise = n * factorial (n - 1)

message-index/messages/GHC-44432/typo/before/MissingBinding.hs

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+module MissingBinding where
+
+import Numeric.Natural
+
+factorial :: Natural -> Natural
+fatcorial n
+  | n == 0 = 1
+  | otherwise = n * factorial (n - 1)

message-index/messages/GHC-44432/typo/index.md

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+---
+title: Type signature lacks an accompanying binding
+---
+
+If a type signature is given for a name in a Haskell module, then the name also needs to be defined.
+
+In this example, the programmer misspelt the name `factorial`.
+GHC helpfully suggests that `fatcorial` might be the intended spelling.
+The error can be fixed by correcting the typo.
+
+## Error Message
+
+```
+MissingBinding.hs:5:1: error: [GHC-44432]
+    The type signature for ‘factorial’ lacks an accompanying binding
+    Suggested fix: Perhaps use ‘fatcorial’ (Defined at Main.hs:6:1)
+  |
+5 | factorial :: Natural -> Natural
+  | ^^^^^^^^^
+```