a simple parser using the mpc parser combinator library.

that such a thing even exists...

bonus points for using peg's? but then what ast would we get? mhh...

c/mul/.gitignore

/mpc.c
/mpc.h
/mul

c/mul/Makefile

run: mul
	./mul
mul: main.c
	$(CC) -ledit main.c -o mul
mul: main.c mpc.c mpc.h
	$(CC) -ledit -lm mpc.c main.c -o mul
mpc_base_url=https://raw.githubusercontent.com/orangeduck/mpc/a25dc955a
mpc.h:
	curl -O $(mpc_base_url)/mpc.h
mpc.c:
	curl -O $(mpc_base_url)/mpc.c
clean:
	rm -f mul

c/mul/main.c

#include <editline/readline.h>
#include "mpc.h"
int main(int argc, char** argv) {
	mpc_parser_t* Number = mpc_new("number");
	mpc_parser_t* Operator = mpc_new("operator");
	mpc_parser_t* Expr = mpc_new("expr");
	mpc_parser_t* Lang = mpc_new("lang");
	mpca_lang(MPC_LANG_DEFAULT,
		"\
number   : /-?[0-9]+/ ; \
operator : '+' | '-' | '*' | '/' ; \
expr     : <number> | '(' <operator> <expr>+ ')' ; \
lang     : /^/ <expr>+ /$/ ; \
",
		Number, Operator, Expr, Lang);
	puts("mul v0.0.1\n");
	while (1) {
		char* input = readline("> ");
		add_history(input);
		printf("%s, yes.", input);
		mpc_result_t r;
		if (mpc_parse("<stdin>", input, Lang, &r)) {
			mpc_ast_print(r.output);
			mpc_ast_delete(r.output);
		} else {
			mpc_err_print(r.error);
			mpc_err_delete(r.error);
		}
		free(input);
	}
	mpc_cleanup(4, Number, Operator, Expr, Lang);
	return 0;
}