Forth-style Stack Language in C. Runs natively or, in browser via wasm. Live demo at [https://danielrholland.codeberg.page/forth-style-stack-lang/](https://danielrholland.codeberg.page/forth-style-stack-lang/) Assuming you have clang and make installed, the native executable can be built with `make build`, then run with `./forth`. If you also have rlwrap installed, you can run `make run-rlwrap`, to get completions, history, and more pleasant line-editing. `make build-wasm` will build the wasm version. Serve `./forthlib.wasm`, `forthlib.js`, `forth.js` and `index.html` from a web server and open `index.html` to use it. ---- Current builtin operations: - `.` - pop and print val - `peek` - peek and print val - `+` - pop top two vals and push second+top - `-` - pop top two vals and push second-top - `*` - pop top two vals and push second*top - `/` - pop top two vals and push second/top - `negate` - replace top val with 0 - value - `abs` - replace top val with its absolute - `mod` - second modulo top - `max` - largest of top two vals - `min` - largest of top two vals - `dup` - duplicate top val - `not` - if top val is 0 set to 1, else set to 0 - `=` - pop top two vals - `swap` - swap order of top two vals - `drop` - discard top val - `over` - copy second val and push it - `rot` - rotate top three vals - top to third, second to top, third to second - `pick` - pop a val n, then copy the nth value down from the top and push it - `roll` - pop a val n, then copy the nth value down from the top and push it - `depth` - push that stack size - `clearstack` - clear the stack - `if then ` - an optional section. `if` pops a val, and if that val is 0, skips to then. (Branch if zero) - `: ;` - a procedure declaration. A new op is added, when it is run, the tokens in the body are evaluated. e.g. `: incr 1 + ; ` will define a new operation `incr`, that increments the value at the top of the stack. - `nip` - discards the second val from the top - `tuck` - copies the top val and inserts it between the second and third - `incr` - increments the top value Literals are pushed. At present only integers are supported. At present, loops haven't been added, just use recursion. ---- Released into the public domain.