Comment by feeley

Haven't looked at what it would take to support C89 (or other) fully. Certainly it is possible to extend the compiler in small increments to implement more stuff: all the operators, local variables, arrays, pointers, functions, etc. The hardest part I would say is implementing types (starting with the C syntax for types!) and also handling the memory allocation for them. Nothing too complex when you know what you are doing. My personal interest is with higher-level languages and I have worked on various Scheme systems over the last 30 years. If you like small language implementations then take a look at Ribbit which is feature-full with a tiny VM. Also check out sectorlisp (not my work) which is a fascinating tour de force.