Program Verification

[Tyler-Yates]

Verify that the image files given to the interpreter are valid program.

Some ideas:

• Image width and height must be divisible by codel size
• Unknown colors should cause a warning message

[Tyler-Yates]

Documentation from http://www.dangermouse.net/esoteric/piet.html states:

Additional colours (such as orange, brown) may be used, though their effect is implementation-dependent. In the simplest case, non-standard colours are treated by the language interpreter as the same as white, so may be used freely wherever white is used. (Another possibility is that they are treated the same as black.)

I think treating non-standard colors as white is reasonable.