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mirror of https://github.com/janet-lang/janet synced 2024-11-14 04:34:48 +00:00
janet/core/value.c
Calvin Rose d84cc5342e Fix write after free bug.
Remove caching from strings, tuples, and structs.
Keyword style strings removed, now are just symbols. The
compiler can decide to treat symbols with a leading ':'
differently for mostly the same effect. This was done because
as strings are no longer interned, symbols are cheaper to look
up and check for equality.
2017-11-27 14:03:34 -05:00

324 lines
10 KiB
C

/*
* Copyright (c) 2017 Calvin Rose
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <dst/dst.h>
/*
* Define a number of functions that can be used internally on ANY DstValue.
*/
/* Boolean truth definition */
int dst_truthy(DstValue v) {
return v.type != DST_NIL && !(v.type == DST_BOOLEAN && !v.as.boolean);
}
/* Check if two values are equal. This is strict equality with no conversion. */
int dst_equals(DstValue x, DstValue y) {
int result = 0;
if (x.type != y.type) {
result = 0;
} else {
switch (x.type) {
case DST_NIL:
result = 1;
break;
case DST_BOOLEAN:
result = (x.as.boolean == y.as.boolean);
break;
case DST_REAL:
result = (x.as.real == y.as.real);
break;
case DST_INTEGER:
result = (x.as.integer == y.as.integer);
break;
case DST_STRING:
result = dst_string_equal(x.as.string, y.as.string);
break;
case DST_STRUCT:
result = dst_struct_equal(x.as.st, y.as.st);
break;
default:
/* compare pointers */
result = (x.as.pointer == y.as.pointer);
break;
}
}
return result;
}
/* Computes a hash value for a function */
uint32_t dst_hash(DstValue x) {
uint32_t hash = 0;
switch (x.type) {
case DST_NIL:
hash = 0;
break;
case DST_BOOLEAN:
hash = x.as.boolean;
break;
case DST_STRING:
case DST_SYMBOL:
hash = dst_string_hash(x.as.string);
break;
case DST_TUPLE:
if (0 == dst_tuple_hash(x.as.tuple))
hash = dst_tuple_hash(x.as.tuple) =
dst_array_calchash(x.as.tuple, dst_tuple_length(x.as.tuple));
else
hash = dst_tuple_hash(x.as.tuple);
break;
case DST_STRUCT:
if (0 == dst_struct_hash(x.as.st))
hash = dst_struct_hash(x.as.st) =
dst_array_calchash(x.as.st, dst_struct_capacity(x.as.st));
else
hash = dst_struct_hash(x.as.st);
break;
default:
if (sizeof(double) == sizeof(void *)) {
/* Assuming 8 byte pointer */
uint64_t i = x.as.integer;
hash = (uint32_t)(i >> 32) ^ (uint32_t)(i & 0xFFFFFFFF);
} else {
/* Assuming 4 byte pointer (or smaller) */
hash = (uint32_t) (x.as.pointer - NULL);
}
break;
}
return hash;
}
/* Compares x to y. If they are equal retuns 0. If x is less, returns -1.
* If y is less, returns 1. All types are comparable
* and should have strict ordering. */
int dst_compare(DstValue x, DstValue y) {
if (x.type == y.type) {
switch (x.type) {
case DST_NIL:
return 0;
case DST_BOOLEAN:
if (x.as.boolean == y.as.boolean) {
return 0;
} else {
return x.as.boolean ? 1 : -1;
}
case DST_REAL:
/* Check for nans to ensure total order */
if (x.as.real != x.as.real)
return y.as.real != y.as.real
? 0
: -1;
if (y.as.real != y.as.real)
return 1;
if (x.as.real == y.as.real) {
return 0;
} else {
return x.as.real > y.as.real ? 1 : -1;
}
case DST_INTEGER:
if (x.as.integer == y.as.integer) {
return 0;
} else {
return x.as.integer > y.as.integer ? 1 : -1;
}
case DST_STRING:
return dst_string_compare(x.as.string, y.as.string);
case DST_TUPLE:
return dst_tuple_compare(x.as.tuple, y.as.tuple);
case DST_STRUCT:
return dst_struct_compare(x.as.st, y.as.st);
default:
if (x.as.string == y.as.string) {
return 0;
} else {
return x.as.string > y.as.string ? 1 : -1;
}
}
} else if (x.type < y.type) {
return -1;
}
return 1;
}
/* Get a value out af an associated data structure. For invalid
* data structure or invalid key, returns nil. */
DstValue dst_get(DstValue ds, DstValue key) {
switch (ds.type) {
case DST_ARRAY:
if (key.type == DST_INTEGER &&
key.as.integer >= 0 &&
key.as.integer < ds.as.array->count)
return ds.as.array->data[key.as.integer];
break;
case DST_TUPLE:
if (key.type == DST_INTEGER &&
key.as.integer >= 0 &&
key.as.integer < dst_tuple_length(ds.as.tuple))
return ds.as.tuple[key.as.integer];
break;
case DST_BUFFER:
if (key.type == DST_INTEGER &&
key.as.integer >= 0 &&
key.as.integer < ds.as.buffer->count)
return dst_wrap_integer(ds.as.buffer->data[key.as.integer]);
break;
case DST_STRING:
case DST_SYMBOL:
if (key.type == DST_INTEGER &&
key.as.integer >= 0 &&
key.as.integer < dst_string_length(ds.as.string))
return dst_wrap_integer(ds.as.string[key.as.integer]);
break;
case DST_STRUCT:
return dst_struct_get(ds.as.st, key);
case DST_TABLE:
return dst_table_get(ds.as.table, key);
default:
break;
}
return dst_wrap_nil();
}
/* Set a value in an associative data structure. Returns possible
* error message, and NULL if no error. */
void dst_put(DstValue ds, DstValue key, DstValue value) {
switch (ds.type) {
case DST_ARRAY:
if (key.type == DST_INTEGER &&
key.as.integer >= 0 &&
key.as.integer < ds.as.array->count)
ds.as.array->data[key.as.integer] = value;
return;
case DST_BUFFER:
if (key.type == DST_INTEGER &&
value.type == DST_INTEGER &&
key.as.integer >= 0 &&
key.as.integer < ds.as.buffer->count)
ds.as.buffer->data[key.as.integer] = value.as.integer;
return;
case DST_TABLE:
dst_table_put(ds.as.table, key, value);
return;
default:
return;
}
}
/* Get the next key in an associative data structure. Used for iterating through an
* associative data structure. */
DstValue dst_next(DstValue ds, DstValue key) {
switch(ds.type) {
default:
return dst_wrap_nil();
case DST_TABLE:
return dst_table_next(ds.as.table, key);
case DST_STRUCT:
return dst_struct_next(ds.as.st, key);
}
}
/* Get the length of an object. Returns errors for invalid types */
uint32_t dst_length(DstValue x) {
switch (x.type) {
default:
return 0;
case DST_STRING:
return dst_string_length(x.as.string);
case DST_ARRAY:
return x.as.array->count;
case DST_BUFFER:
return x.as.buffer->count;
case DST_TUPLE:
return dst_tuple_length(x.as.tuple);
case DST_STRUCT:
return dst_struct_length(x.as.st);
case DST_TABLE:
return x.as.table->count;
}
}
/* Get the capacity of an object. Returns 0 for invalid types */
uint32_t dst_capacity(DstValue x) {
switch (x.type) {
default:
return 0;
case DST_STRING:
return dst_string_length(x.as.string);
case DST_ARRAY:
return x.as.array->capacity;
case DST_BUFFER:
return x.as.buffer->capacity;
case DST_TUPLE:
return dst_tuple_length(x.as.tuple);
case DST_STRUCT:
return dst_struct_length(x.as.st);
case DST_TABLE:
return x.as.table->capacity;
}
}
/* Index into a data structure. Returns nil for out of bounds or invliad data structure */
DstValue dst_getindex(DstValue ds, uint32_t index) {
switch (ds.type) {
default:
return dst_wrap_nil();
case DST_STRING:
if (index >= dst_string_length(ds.as.string)) return dst_wrap_nil();
return dst_wrap_integer(ds.as.string[index]);
case DST_ARRAY:
if (index >= ds.as.array->count) return dst_wrap_nil();
return ds.as.array->data[index];
case DST_BUFFER:
if (index >= ds.as.buffer->count) return dst_wrap_nil();
return dst_wrap_integer(ds.as.buffer->data[index]);
case DST_TUPLE:
if (index >= dst_tuple_length(ds.as.tuple)) return dst_wrap_nil();
return ds.as.tuple[index];
}
}
/* Set an index in a linear data structure. Does nothing if data structure
* is invalid */
void dst_setindex(DstValue ds, DstValue value, uint32_t index) {
switch (ds.type) {
default:
return;
case DST_ARRAY:
if (index >= ds.as.array->count) {
dst_array_ensure(ds.as.array, 2 * index);
ds.as.array->count = index + 1;
}
ds.as.array->data[index] = value;
return;
case DST_BUFFER:
if (value.type != DST_INTEGER) return;
if (index >= ds.as.buffer->count) {
dst_buffer_ensure(ds.as.buffer, 2 * index);
ds.as.buffer->count = index + 1;
}
ds.as.buffer->data[index] = value.as.integer;
return;
}
}