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#include "optable.h"
#include <stdio.h>
#include <string.h>
static void not(stack *s);
static void drop(stack *s);
static void over(stack *s);
static void rot(stack *s);
static void swap(stack *s);
static void eq(stack *s);
static void add(stack *s);
static void mult(stack *s);
static void s_div(stack *s);
static void sub(stack *s);
static void dup(stack *s);
static void popout(stack *s);
static void peekout(stack *s);
static void ifdirective(stack *s, int len, char* line, int* i);
static void defineop(stack *s, int len, char* line, int* i);
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wincompatible-function-pointer-types"
// clang seems to not realise that the union can contain fp types beyond the first
static wordop optable[OPTABLE_MAX_SIZE] = {
{".", builtin, {popout}},
{"peek", builtin, {peekout}},
{"+", builtin, {add}},
{"-", builtin, {sub}},
{"*", builtin, {mult}},
{"/", builtin, {s_div}},
{"dup", builtin, {dup}},
{"not", builtin, {not}},
{"=", builtin, {eq}},
{"swap", builtin, {swap}},
{"drop", builtin, {drop}},
{"over", builtin, {over}},
{"rot", builtin, {rot}},
{"if", directive, {ifdirective}},
{":", directive, {defineop}},
};
static int optablelen = 15;
#pragma clang diagnostic pop
wordop* getop(char *word) {
for (int i = 0; i < optablelen; i++) {
if (!strcmp(optable[i].word, word)) {
return &optable[i];
}
}
return 0;
}
/* Implementations of builtin functions */
static void not(stack *s) {
int x = pop(s);
push(s, !x);
}
static void drop(stack *s) {
pop(s);
}
static void over(stack *s) {
int x = pop(s);
int y = pop(s);
push(s, y);
push(s, x);
push(s, y);
}
static void rot(stack *s) {
int x = pop(s);
int y = pop(s);
int z = pop(s);
push(s, y);
push(s, x);
push(s, z);
}
static void swap(stack *s) {
int x = pop(s);
int y = pop(s);
push(s, x);
push(s, y);
}
static void eq(stack *s) {
int x = pop(s);
int y = pop(s);
push(s, x == y);
}
static void add(stack *s) {
int x = pop(s);
int y = pop(s);
push(s, x + y);
}
static void mult(stack *s) {
int x = pop(s);
int y = pop(s);
push(s, x * y);
}
static void s_div(stack *s) {
int x = pop(s);
int y = pop(s);
push(s, y / x);
}
static void sub(stack *s) {
int x = pop(s);
int y = pop(s);
push(s, y - x);
}
static void dup(stack *s) {
int x = pop(s);
push(s, x);
push(s, x);
}
static void popout(stack *s) {
printf("%d\n", pop(s));
}
static void peekout(stack *s) {
int x = pop(s);
push(s, x);
printf("%d\n", x);
}
/* Directives */
static void ifdirective(stack *s, int len, char* line, int* i) {
stackitem predicate = pop(s);
if (!predicate) {
while (len > *i && !(
line[*i-3] == 't' &&
line[*i-2] == 'h' &&
line[*i-1] == 'e' &&
line[*i] == 'n'
)) {
(*i)++;
}
}
}
/**
* defineop reads a function identifier, followed by the commands to run when the function
* is called, stopping when a semicolon is reached.
* Reading is done from the input string.
*
* returns new position of input index
*
*/
static void defineop(stack* s_IGNORED, int len_IGNORED, char *input, int* starti) {
// value easier to deal with (than pointer)
int i = *starti;
// name by which the function will be called
char *opcode = malloc(sizeof(char) * WORD_LEN_LIMIT);
int opcodei = 0;
// code to be evaluated when function is called
char *funcscript = malloc(sizeof(char) * DEFINED_FUNC_MAX_LENGTH);
int funcscripti = 0;
// skip ' ' and ':'
while (input[i] == ' ' || input[i] == ':') {
i++;
}
// get name
while (input[i] != ' ' && opcodei < WORD_LEN_LIMIT) {
opcode[opcodei++] = input[i++];
}
opcode[opcodei] = '\0';
// get code
while (input[i] != ';' && funcscripti < DEFINED_FUNC_MAX_LENGTH) {
funcscript[funcscripti++] = input[i++];
}
funcscript[funcscripti] = '\0';
// optable bounds check
if (optablelen >= OPTABLE_MAX_SIZE) {
// Error
fprintf(stderr, "Error: optable reached max size, failed to create new user defined operation");
exit(1);
}
// add op to end of table, and increment size
optable[optablelen].word = opcode;
optable[optablelen].optype = script;
optable[optablelen].script = funcscript;
optable[optablelen].scriptlen = funcscripti;
optablelen++;
// move read position forwards
*starti = i;
}
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