prompt.c

#include <stdio.h>
#include <stdlib.h>
#include "mpc.h"

/* If we are compiling on Windows compile these functions */
#ifdef _WIN32
#include <string.h>

static char buffer[2048];

/* Fake readline function */
char* readline(char* prompt) {
	fputs(prompt, stdout);
	fgets(buffer, 2048, stdin);
	char* cpy = malloc(strlen(buffer) + 1);
	strcpy(cpy, buffer);
	cpy[strlen(cpy) - 1] = '\0';
	return cpy;
}

/* Fake add_history function */
void add_history(char* unused) {}

/* Otherwise include the editline header */
#else
#include <editline/readline.h>
#include <editline/history.h>
#endif

int main(int argc, char** argv) {

	/* Crete Some Parsers */
	mpc_parser_t* Number	= mpc_new("number");
	mpc_parser_t* Operator	= mpc_new("operator");
	mpc_parser_t* Expr		= mpc_new("expr");
	mpc_parser_t* Lispy		= mpc_new("lispy");

	/* Define them with the following Language */
	mpca_lang(MPCA_LANG_DEFAULT,
			"											\
				number	: /-?[0-9]+/ ;					\
				operator: '+' | '-' | '*' | '/' ;		\
				expr	: <number> | '(' <operator> <expr>+ ')' ;	\
				lispy	: /^/ <operator> <expr>+ /$/ ;	\
			",
			Number, Operator, Expr, Lispy);

	puts("Lispy Version 0.0.0.0.1");
	puts("Press Ctrl+c to Exit\n");

	while (1) {

		/* Now in either case readline will be correctly defined */
		char* input = readline("lispy> ");
		add_history(input);

		/*printf("No you're a %s\n", input);*/
		/* Attempt to Parse the user Input */
		mpc_result_t r;
		if (mpc_parse("<stdin>", input, Lispy, &r)) {
			/* On Success Print the AST */
			mpc_ast_print(r.output);
			mpc_ast_delete(r.output);
		} else {
			/* Otherwise Print the Error */
			mpc_err_print(r.error);
			mpc_err_delete(r.error);
		}
		free(input);
	}

	/* Undefine and Delete our Parsers */
	mpc_cleanup(4, Number, Operator, Expr, Lispy);
	return 0;
}