diff options
| -rw-r--r-- | ChangeLog | 17 | ||||
| -rw-r--r-- | hash.c | 2 | ||||
| -rw-r--r-- | lib.c | 60 | ||||
| -rw-r--r-- | lib.h | 31 |
4 files changed, 64 insertions, 46 deletions
@@ -1,5 +1,22 @@ 2009-11-06 Kaz Kylheku <kkylheku@gmail.com> + Changing representation of objects to allow for unboxed characters. + Now numbers and characters fit into a cell. We lose one more bit + from the range of numbers. + + * lib.h (TAG_SHIFT, TAG_MASK, TAG_NUM, TAG_PTR, NUM_MASK, NUM_MIN, + is_ptr, is_num): Macros updated. + (is_chr, tag): New macros. + (struct chr): Removed. + (union obj): Updated. + + * lib.c (typeof, equal, chr, chrp, c_chr, obj_print): Updated. + + * hash.c (ll_hash): Characters aren't pointers any longer; + use abstract accessor. + +2009-11-06 Kaz Kylheku <kkylheku@gmail.com> + Add hash removal. * hash.c (remhash): New function. @@ -87,7 +87,7 @@ static long ll_hash(obj_t *obj) case STR: return hash_c_str(obj->st.str); case CHR: - return obj->ch.ch + NUM_MAX / 2; + return c_chr(obj) + NUM_MAX / 2; case NUM: return c_num(obj) & NUM_MAX; case SYM: @@ -101,17 +101,24 @@ static obj_t *code2type(int code) obj_t *typeof(obj_t *obj) { - if (is_num(obj)) { + switch (tag(obj)) { + case TAG_NUM: return num_t; - } else if (obj == nil) { - return null; - } else if (obj->t.type == COBJ) { - return obj->co.cls; - } else { - obj_t *type = code2type(obj->t.type); - if (!type) - internal_error("corrupt type field"); - return type; + case TAG_CHR: + return chr_t; + case TAG_PTR: + if (obj == nil) { + return null; + } else if (obj->t.type == COBJ) { + return obj->co.cls; + } else { + obj_t *type = code2type(obj->t.type); + if (!type) + internal_error("corrupt type field"); + return type; + } + default: + internal_error("invalid type tag"); } } @@ -398,10 +405,16 @@ long c_num(obj_t *num); obj_t *equal(obj_t *left, obj_t *right) { - if (left == nil && right == nil) + /* Bitwise equality is equality. + The object nil, and types CHR and NUM + need no further test. */ + if (left == right) return t; - if (left == nil || right == nil) + /* If the objects are not bitwise equal, + and any one of them is not a pointer, + then they can't be equal. */ + if (!is_ptr(left) || !is_ptr(right)) return nil; switch (type(left)) { @@ -422,14 +435,6 @@ obj_t *equal(obj_t *left, obj_t *right) return equal(left, right->ls.prefix); } return nil; - case CHR: - if (type(right) == CHR && left->ch.ch == right->ch.ch) - return t; - return nil; - case NUM: - if (type(right) == NUM && c_num(left) == c_num(right)) - return t; - return nil; case SYM: return right == left ? t : nil; case FUN: @@ -952,21 +957,20 @@ obj_t *string_lt(obj_t *astr, obj_t *bstr) obj_t *chr(int ch) { - obj_t *obj = make_obj(); - obj->ch.type = CHR; - obj->ch.ch = ch; - return obj; + numeric_assert (ch >= NUM_MIN && ch <= NUM_MAX); + return (obj_t *) ((ch << TAG_SHIFT) | TAG_CHR); } obj_t *chrp(obj_t *chr) { - return (chr && chr->st.type == CHR) ? t : nil; + return (is_chr(num)) ? t : nil; } int c_chr(obj_t *chr) { - type_check(chr, CHR); - return chr->ch.ch; + if (!is_chr(chr)) + type_mismatch("~s is not a character", chr, nao); + return ((int) chr) >> TAG_SHIFT; } obj_t *chr_str(obj_t *str, obj_t *index) @@ -1848,7 +1852,7 @@ void obj_print(obj_t *obj, obj_t *out) return; case CHR: { - int ch = obj->ch.ch; + int ch = c_chr(obj); put_cchar(out, '\''); switch (ch) { @@ -24,8 +24,16 @@ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ +#define TAG_SHIFT 2 +#define TAG_MASK ((1 << TAG_SHIFT) - 1) +#define TAG_PTR 0 +#define TAG_NUM 1 +#define TAG_CHR 2 +#define NUM_MAX (LONG_MAX/4) +#define NUM_MIN (LONG_MIN/4) + typedef enum type { - CONS = 1, STR, CHR, NUM, SYM, FUN, VEC, LCONS, LSTR, COBJ + NUM = TAG_NUM, CHR = TAG_CHR, CONS, STR, SYM, FUN, VEC, LCONS, LSTR, COBJ } type_t; typedef enum functype @@ -35,16 +43,11 @@ typedef enum functype N0, N1, N2, N3, N4 /* No-env intrinsics. */ } functype_t; -#define TAG_SHIFT 1 -#define TAG_MASK ((1 << TAG_SHIFT) - 1) -#define TAG_NUM 1 -#define TAG_PTR 0 -#define NUM_MAX (LONG_MAX/2) -#define NUM_MIN (LONG_MIN/2) - -#define is_ptr(obj) ((obj) && (((long) obj) & TAG_MASK) == TAG_PTR) -#define is_num(obj) ((((long) obj) & TAG_MASK) == TAG_NUM) -#define type(obj) ((is_num(obj)) ? NUM : obj->t.type) +#define tag(obj) (((long) (obj)) & TAG_MASK) +#define is_ptr(obj) ((obj) && (tag(obj) == TAG_PTR)) +#define is_num(obj) (tag(obj) == TAG_NUM) +#define is_chr(obj) (tag(obj) == TAG_CHR) +#define type(obj) (tag(obj) ? ((type_t) tag(obj)) : obj->t.type) typedef union obj obj_t; @@ -65,11 +68,6 @@ struct string { obj_t *len; }; -struct chr { - type_t type; - int ch; -}; - struct sym { type_t type; obj_t *name; @@ -149,7 +147,6 @@ union obj { struct any t; struct cons c; struct string st; - struct chr ch; struct sym s; struct func f; struct vec v; |