-

- is a joke esoteric programming language by Grs (talk). The language will deny everything the programmer tells it to do, except...

Command

Command

Command	Description
-	prints "Hello, World!"

Everything that is not a dash prints "I will not do that!".

Code

Hello, World!

-

I will not do that!

a

Quine

I will not do that!

Implementation

Here is a REPL-style implementation written in Python 3.

def dash(code):
  for c in code:
    if c == "-":
      print("Hello, World!")
    else:
      print("I will not do that!")

while len(code := input("> ")) > 0:
  dash(code)