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mirror of https://github.com/janet-lang/janet synced 2024-11-15 13:14:48 +00:00
janet/core/value.c

254 lines
8.4 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 <gst/gst.h>
#include <stdio.h>
/* Boolean truth definition */
int gst_truthy(GstValue v) {
return v.type != GST_NIL && !(v.type == GST_BOOLEAN && !v.data.boolean);
}
/* Check if two values are equal. This is strict equality with no conversion. */
int gst_equals(GstValue x, GstValue y) {
int result = 0;
if (x.type != y.type) {
result = 0;
} else {
switch (x.type) {
case GST_NIL:
result = 1;
break;
case GST_BOOLEAN:
result = (x.data.boolean == y.data.boolean);
break;
case GST_REAL:
result = (x.data.real == y.data.real);
break;
case GST_INTEGER:
result = (x.data.integer == y.data.integer);
break;
default:
/* compare pointers */
result = (x.data.pointer == y.data.pointer);
break;
}
}
return result;
}
/* Computes a hash value for a function */
uint32_t gst_hash(GstValue x) {
uint32_t hash = 0;
switch (x.type) {
case GST_NIL:
hash = 0;
break;
case GST_BOOLEAN:
hash = x.data.boolean;
break;
case GST_STRING:
case GST_SYMBOL:
hash = gst_string_hash(x.data.string);
break;
case GST_TUPLE:
hash = gst_tuple_hash(x.data.tuple);
break;
case GST_STRUCT:
hash = gst_struct_hash(x.data.st);
break;
default:
if (sizeof(double) == sizeof(void *)) {
/* Assuming 8 byte pointer */
hash = x.data.dwords[0] ^ x.data.dwords[1];
} else {
/* Assuming 4 byte pointer (or smaller) */
hash = (uint32_t) x.data.pointer;
}
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 gst_compare(GstValue x, GstValue y) {
if (x.type == y.type) {
switch (x.type) {
case GST_NIL:
return 0;
case GST_BOOLEAN:
if (x.data.boolean == y.data.boolean) {
return 0;
} else {
return x.data.boolean ? 1 : -1;
}
case GST_REAL:
if (x.data.real == y.data.real) {
return 0;
} else {
return x.data.real > y.data.real ? 1 : -1;
}
case GST_INTEGER:
if (x.data.integer == y.data.integer) {
return 0;
} else {
return x.data.integer > y.data.integer ? 1 : -1;
}
case GST_STRING:
return gst_string_compare(x.data.string, y.data.string);
/* Lower indices are most significant */
case GST_TUPLE:
{
uint32_t i;
uint32_t xlen = gst_tuple_length(x.data.tuple);
uint32_t ylen = gst_tuple_length(y.data.tuple);
uint32_t count = xlen < ylen ? xlen : ylen;
for (i = 0; i < count; ++i) {
int comp = gst_compare(x.data.tuple[i], y.data.tuple[i]);
if (comp != 0) return comp;
}
if (xlen < ylen)
return -1;
else if (xlen > ylen)
return 1;
return 0;
}
break;
default:
if (x.data.string == y.data.string) {
return 0;
} else {
return x.data.string > y.data.string ? 1 : -1;
}
}
} else if (x.type < y.type) {
return -1;
}
return 1;
}
/* Get a value out af an associated data structure.
* Returns possible c error message, and NULL for no error. The
* useful return value is written to out on success */
const char *gst_get(GstValue ds, GstValue key, GstValue *out) {
GstInteger index;
GstValue ret;
switch (ds.type) {
case GST_ARRAY:
if (key.type != GST_INTEGER) return "expected integer key";
index = gst_startrange(key.data.integer, ds.data.array->count);
if (index < 0) return "invalid array access";
ret = ds.data.array->data[index];
break;
case GST_TUPLE:
if (key.type != GST_INTEGER) return "expected integer key";
index = gst_startrange(key.data.integer, gst_tuple_length(ds.data.tuple));
if (index < 0) return "invalid tuple access";
ret = ds.data.tuple[index];
break;
case GST_BYTEBUFFER:
if (key.type != GST_INTEGER) return "expected integer key";
index = gst_startrange(key.data.integer, ds.data.buffer->count);
if (index < 0) return "invalid buffer access";
ret.type = GST_INTEGER;
ret.data.integer = ds.data.buffer->data[index];
break;
case GST_STRING:
case GST_SYMBOL:
if (key.type != GST_INTEGER) return "expected integer key";
index = gst_startrange(key.data.integer, gst_string_length(ds.data.string));
if (index < 0) return "invalid string access";
ret.type = GST_INTEGER;
ret.data.integer = ds.data.string[index];
break;
case GST_STRUCT:
ret = gst_struct_get(ds.data.st, key);
break;
case GST_TABLE:
ret = gst_table_get(ds.data.table, key);
break;
default:
return "cannot get";
}
*out = ret;
return NULL;
}
/* Set a value in an associative data structure. Returns possible
* error message, and NULL if no error. */
const char *gst_set(Gst *vm, GstValue ds, GstValue key, GstValue value) {
GstInteger index;
switch (ds.type) {
case GST_ARRAY:
if (key.type != GST_INTEGER) return "expected integer key";
index = gst_startrange(key.data.integer, ds.data.array->count);
if (index < 0) return "invalid array access";
ds.data.array->data[index] = value;
break;
case GST_BYTEBUFFER:
if (key.type != GST_INTEGER) return "expected integer key";
if (value.type != GST_INTEGER) return "expected integer value";
index = gst_startrange(key.data.integer, ds.data.buffer->count);
if (index < 0) return "invalid buffer access";
ds.data.buffer->data[index] = (uint8_t) value.data.integer;
break;
case GST_TABLE:
gst_table_put(vm, ds.data.table, key, value);
break;
default:
return "cannot set";
}
return NULL;
}
/* Get the length of an object. Returns errors for invalid types */
GstInteger gst_length(Gst *vm, GstValue x) {
GstInteger length;
switch (x.type) {
default:
vm->ret = gst_string_cv(vm, "cannot get length");
return GST_RETURN_ERROR;
case GST_STRING:
length = gst_string_length(x.data.string);
break;
case GST_ARRAY:
length = x.data.array->count;
break;
case GST_BYTEBUFFER:
length = x.data.buffer->count;
break;
case GST_TUPLE:
length = gst_tuple_length(x.data.tuple);
break;
case GST_STRUCT:
length = gst_struct_length(x.data.st);
break;
case GST_TABLE:
length = x.data.table->count;
break;
}
return length;
}