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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},
};
int compare(const void *s1, const void *s2) {
char *left = *(char **)s1;
char *right = *(char **)s2;
return strcmp(left, right);
}
int search(const void *s1, const void *s2) {
char *name = *(char **)s1;
command c = *(command *)s2;
return (strcmp(name, c.name));
}
void init_state(state *s) {
int numel = sizeof(CMD_LIST)/sizeof(CMD_LIST[0]);
qsort(&CMD_LIST, numel, sizeof(CMD_LIST[0]), compare);
s->numel = numel;
s->sorted = CMD_LIST;
}
void exec(char *buf, state *s) {
command *c = bsearch(&buf, s->sorted, sizeof(CMD_LIST)/sizeof(s->sorted[0]), sizeof(s->sorted[0]), search);
if (c == NULL) {
fprintf(s->defout, "error: function '%s' not found\n", buf);
return;
}
if (c->required_args > s->stk.count) {
fprintf(s->defout,"this function requires %d arguments\n", c->required_args);
return;
}
fprintf(s->defout, "executing function: %s\n", c->name);
s->stk = c->exec(s->stk);
}
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