DM's Esoteric Programming Languages - Piet
Piet is a programming language in which programs look like abstract paintings. The language is named after Piet Mondrian, who pioneered the field of geometric abstract art. I would have liked to call the language Mondrian, but someone beat me to it with a rather mundane-looking scripting language. Oh well, we can't all be esoteric language writers I suppose.
Piet uses 20 distinct colours, as shown in the table at right. The 18 colours in the first 3 rows of the table are related cyclically in the following two ways:
Note that "light" is considered to be one step "darker" than "dark", and vice versa. White and black do not fall into either cycle.
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.)
Piet code takes the form of graphics made up of the recognised colours. Individual pixels of colour are significant in the language, so it is common for programs to be enlarged for viewing so that the details are easily visible. In such enlarged programs, the term "codel" is used to mean a block of colour equivalent to a single pixel of code, to avoid confusion with the actual pixels of the enlarged graphic, of which many may make up one codel.
