Documentation

Simply wraps a generic Diagnostic message.

DsEmptyEnumeration is a warning (controlled by the -Wempty-enumerations flag) that is emitted if an enumeration is empty.

Example(s):

main :: IO () main = do let enum = [5 .. 3] print enum

Here enum would yield an empty list, because 5 is greater than 3.

Test case(s): warningsshould_compileT10930 warningsshould_compileT18402 warningsshould_compileT10930b numericshould_compileT10929 numericshould_compileT7881 deSugarshould_runT18172

DsIdentitiesFound is a warning (controlled by the -Widentities flag) that is emitted on uses of Prelude numeric conversions that are probably the identity (and hence could be omitted).

Example(s):

main :: IO () main = do let x = 10 print $ conv 10

where conv :: Int -> Int conv x = fromIntegral x

Here calling conv is essentially the identity function, and therefore can be omitted.

Test case(s): deSugarshould_compileT4488