Files
imp/lib/prim.c

75 lines
1.7 KiB
C

#include "prim.h"
#include "env.h"
#include <assert.h>
#define NELEMS(arr) (sizeof(arr) / sizeof(arr[0]))
typedef struct {
const char *name;
prim_proc_t prim_proc;
} prim_table_entry_t;
static void add(am_t *am)
{
assert(AM_ARGL(am));
int64_t total = 0;
for (expr_t *list = AM_ARGL(am); !list->is_atom; list = list->pair.cdr) {
assert(list->pair.car->is_atom);
assert(list->pair.car->atom.type == ATOM_TYPE_INTEGER);
total += list->pair.car->atom.integer;
}
AM_VAL(am) = expr_integer(am, total);
}
static void mul(am_t *am)
{
assert(AM_ARGL(am));
int64_t total = 1;
for (expr_t *list = AM_ARGL(am); !list->is_atom; list = list->pair.cdr) {
assert(list->pair.car->is_atom);
assert(list->pair.car->atom.type == ATOM_TYPE_INTEGER);
total *= list->pair.car->atom.integer;
}
AM_VAL(am) = expr_integer(am, total);
}
static void sub(am_t *am)
{
assert(AM_ARGL(am));
assert(!AM_ARGL(am)->is_atom);
assert(AM_ARGL(am)->pair.car->is_atom);
assert(AM_ARGL(am)->pair.car->atom.type == ATOM_TYPE_INTEGER);
int64_t total = AM_ARGL(am)->pair.car->atom.integer;
if (!AM_ARGL(am)->is_atom && AM_ARGL(am)->pair.cdr->is_atom) {
total *= -1;
} else {
for (expr_t *list = AM_ARGL(am)->pair.cdr; !list->is_atom;
list = list->pair.cdr) {
assert(list->pair.car->is_atom);
assert(list->pair.car->atom.type == ATOM_TYPE_INTEGER);
total -= list->pair.car->atom.integer;
}
}
AM_VAL(am) = expr_integer(am, total);
}
static const prim_table_entry_t prim_table[] = {
{ "+", add },
{ "*", mul },
{ "-", sub },
};
void prim_load(am_t *am)
{
for (unsigned i = 0; i < NELEMS(prim_table); ++i) {
AM_EXPR(am) = expr_str_symbol(am, prim_table[i].name);
AM_VAL(am) = expr_prim_proc(am, prim_table[i].prim_proc);
env_set(am);
}
}