nukeyfox/regmachineprolog

The CST Register machine in its full declarative glory

Register machine interpreter implementation in Prolog

Usage:

?- compute(Registers, Program, Output).

?- computeFromFile(Filename, Registers, Output).

Instructions clauses come in three flavours:

• inc(R, L) = increment register R's content and jump to instruction labelled L
• dec(R, L1, L2) = if register R > 0, decrement R's contents and jump to instruction labelled L1, or if R == 0, jump to instruction labelled L2
• hALT = halts the program. ( halt is a keyword in Prolog so I couldn't use it :C )

The files which can be read as register machine programs are a list of Prolog clauses and are .pl files themselves. For example, a program to compute f(x,y) = x+y addition.pl would be:

dec(1,1,2).
inc(0,0).
dec(2,3,4).
inc(0,2).
hALT.

You can try to search for programs (e.g. compute([0,1], X, [1,0])) but its almost guaranteed to crash or loop forever.