Files
imp/lib/eval.c

60 lines
1.1 KiB
C

#include "eval.h"
#include "env.h"
#include <assert.h>
static void eval_atom(am_t *am)
{
switch (AM_EXPR(am)->atom.type) {
case ATOM_TYPE_EMPTY_LIST:
case ATOM_TYPE_INTEGER:
case ATOM_TYPE_PRIM_PROC:
AM_VAL(am) = AM_EXPR(am);
break;
case ATOM_TYPE_SYMBOL:
env_fetch(am);
break;
}
}
static void eval_list(am_t *am)
{
AM_ARGL(am) = expr_empty_list(am);
AM_UNEV(am) = AM_EXPR(am)->pair.cdr;
AM_EXPR(am) = AM_EXPR(am)->pair.car;
while (!AM_UNEV(am)->is_atom) {
am_push(am, EXPR);
AM_EXPR(am) = AM_UNEV(am)->pair.cdr;
am_push(am, EXPR);
am_push(am, ARGL);
AM_EXPR(am) = AM_UNEV(am)->pair.car;
eval(am);
am_pop(am, ARGL);
am_append(am, ARGL, VAL);
am_pop(am, UNEV);
am_pop(am, EXPR);
}
assert(AM_EXPR(am)->is_atom);
assert(AM_EXPR(am)->atom.type == ATOM_TYPE_SYMBOL);
env_fetch(am);
assert(AM_VAL(am)->is_atom);
assert(AM_VAL(am)->atom.type == ATOM_TYPE_PRIM_PROC);
assert(AM_VAL(am)->atom.prim_proc != NULL);
AM_VAL(am)->atom.prim_proc(am);
}
void eval(am_t *am)
{
if (AM_EXPR(am)->is_atom)
eval_atom(am);
else
eval_list(am);
}