diff options
Diffstat (limited to 'tag.c')
-rw-r--r-- | tag.c | 76 |
1 files changed, 0 insertions, 76 deletions
@@ -1,76 +0,0 @@ -/* Copyright (C) 2025 Aryadev Chavali - - * This program is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS - * FOR A PARTICULAR PURPOSE. See the Unlicense for details. - - * You may distribute and modify this code under the terms of the Unlicense, - * which you should have received a copy of along with this program. If not, - * please go to <https://unlicense.org/>. - - * Created: 2025-08-19 - * Description: Pointer tagging - */ - -#include <assert.h> -#include <stdlib.h> - -#include "./alisp.h" - -lisp_t *tag_int(i64 i) -{ - return TAG((u64)i, INT); -} - -lisp_t *tag_sym(char *str) -{ - return TAG((u64)str, SYM); -} - -lisp_t *tag_vec(vec_t *vec) -{ - return TAG((u64)vec, VEC); -} - -lisp_t *tag_cons(cons_t *cons) -{ - return TAG((u64)cons, CONS); -} - -tag_t get_tag(lisp_t *lisp) -{ - static_assert(NUM_TAGS == 5); - if (!lisp) - return TAG_NIL; - else if (IS_TAG(lisp, INT)) - return TAG_INT; - - return (u64)lisp & 0xFF; -} - -i64 as_int(lisp_t *obj) -{ - assert(IS_TAG(obj, INT)); - u64 p_obj = (u64)obj; - return UNTAG(p_obj, INT) | // Delete the tag - (NTH_BYTE(p_obj, 7) & 0x80) << 56 // duplicate the MSB (preserve sign) - ; -} - -char *as_sym(lisp_t *obj) -{ - assert(IS_TAG(obj, SYM)); - return (char *)UNTAG(obj, SYM); -} - -cons_t *as_cons(lisp_t *obj) -{ - assert(IS_TAG(obj, CONS)); - return (cons_t *)UNTAG(obj, CONS); -} - -vec_t *as_vec(lisp_t *obj) -{ - assert(IS_TAG(obj, VEC)); - return (vec_t *)UNTAG(obj, VEC); -} |