specify posix.ctype:
- before:
    ctype = require "posix.ctype"


- describe isgraph:
  - before:
      isgraph = ctype.isgraph

  - context with bad arguments:
      badargs.diagnose (isgraph, "(string)")

  - it returns non-zero for successful tests:
      expect (type (isgraph 'a')).to_be "number"
      expect (isgraph 'a').not_to_be (0)
  - it returns zero for failed tests:
      expect (isgraph ' ').to_be (0)


- describe isprint:
  - before:
      isprint = ctype.isprint

  - context with bad arguments:
      badargs.diagnose (isprint, "(string)")

  - it returns non-zero for successful tests:
      expect (type (isprint 'a')).to_be "number"
      expect (isprint 'a').not_to_be (0)
  - it returns zero for failed tests:
      expect (isprint (string.char (0))).to_be (0)