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#include "state.h"
#include "cmds.h"
#include <err.h>
#include <math.h>
#include <stdlib.h>
#include <err.h>
#include <string.h>
stack fceil(stack stack) {
stack.val[stack.count-1] = ceil(stack.val[stack.count-1]);
return stack;
}
stack ffloor(stack stack) {
stack.val[stack.count-1] = floor(stack.val[stack.count-1]);
return stack;
}
stack flogB(stack stack) {
stack.val[stack.count-2] = log2(stack.val[stack.count-2])/log2(stack.val[stack.count-1]);
stack.val[--stack.count] = 0;
return stack;
}
stack fnegate(stack stack) {
stack.val[stack.count-1] *= -1;
return stack;
}
stack fpop(stack stack) {
stack.val[--stack.count] = 0;
return stack;
}
command CMD_LIST[] = {
{"p", &fpop, "pop last element", 1},
{"ceil", &fceil, "truncate to the next integer", 1},
{"floor", &ffloor, "truncate to the previous integer", 1},
{"log", &flogB, "calculate logarithm in base LAST_NUM of LAST_NUM-1", 2},
{"neg", &fnegate, "change last element's sign", 1},
{0, 0, 0, 0}
};
void init_state(state *s) {
int numel = 0;
for (int i = 0; CMD_LIST[i].name != 0; i++) numel = i;
command *sorted = malloc(sizeof(command *)*numel);
if (sorted == NULL) err(1, "could not allocate function names");
/* todo: (merge, heap, quick) sort? */
for (int i = 0; CMD_LIST[i].name != 0; i++) {
sorted[i] = CMD_LIST[i];
}
s->sorted = sorted;
}
void exec(char *buf, state *s) {
/* change this to a binary tree search */
for (int i = 0; s->sorted[i].name != 0; i++) {
if (strcmp(buf, s->sorted[i].name) == 0) {
if (s->sorted[i].required_args > s->stk.count) {
fprintf(s->defout,"this function requires %d arguments\n", s->sorted[i].required_args);
return;
}
fprintf(s->defout, "executing function: %s\n", s->sorted[i].name);
s->stk = s->sorted[i].exec(s->stk);
return;
}
}
fprintf(s->defout, "error: function '%s' not found\n", buf);
}
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