all isDigit "" evaluates to True. Should it not evaluate to False?
Summary
import Data.Char (or :m +Data.Char if in GHCi)
all isDigit ""
evaluates to True. Should it not evaluate to False?
import Data.Char (or :m +Data.Char if in GHCi)
all isDigit ""
evaluates to True. Should it not evaluate to False? For example, in ghci:
Prelude> :m +Data.Char
Prelude Data.Char> all isDigit ""
True
Steps to reproduce
See above.
Please provide a set of concrete steps to reproduce the issue.
Launch Terminal utility on MacOS 10.14.5.
$ ghci
GHCi, version 8.2.1: http://www.haskell.org/ghc/ :? for help
...
Prelude> :m +Data.Char
Prelude Data.Char> all isDigit ""
True
Expected behavior
What do you expect the reproducer described above to do?
Evaluate to False, I believe.
Environment
- GHC version used: 8.2.1 on MacOS 10.14.5, Mojave
Optional:
- Operating System: MacOS 10.14.5, Mojave
- System Architecture: Desktop Mac, in Terminal utility