[randyrand]

| int x (>= 0, <=10) | x = parseInt(getKeyboardInput)

Will be a compile time error because getKeyBoard input returns integers that are between 0-256(?) not 0-10 like 'x' wants.

[jarrett]

Exactly. That's why I proposed a Haskell-ish Maybe construct to represent the uncertainty of the input's validity. The code snippet:

  int x (>= 0, <=10) | x = parseInt(getKeyboardInput)

...was meant as an example of what won't work.