DUK_INTERNAL duk_bool_t duk_double_is_nan_or_zero(duk_double_t x) {
duk_double_union du;
du.d = x;
/* Assumes we're dealing with a Duktape internal NaN which is
* NaN normalized if duk_tval requires it.
*/
DUK_ASSERT(DUK_DBLUNION_IS_NORMALIZED(&du));
return DUK_DBLUNION_IS_NAN(&du) || DUK_DBLUNION_IS_ANYZERO(&du);
}
DUK_INTERNAL duk_double_t duk_js_tonumber(duk_hthread *thr, duk_tval *tv) {
duk_context *ctx = (duk_hthread *) thr;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(tv != NULL);
switch (DUK_TVAL_GET_TAG(tv)) {
case DUK_TAG_UNDEFINED: {
/* return a specific NaN (although not strictly necessary) */
duk_double_union du;
DUK_DBLUNION_SET_NAN(&du);
DUK_ASSERT(DUK_DBLUNION_IS_NORMALIZED(&du));
return du.d;
}
case DUK_TAG_NULL: {
/* +0.0 */
return 0.0;
}
case DUK_TAG_BOOLEAN: {
if (DUK_TVAL_IS_BOOLEAN_TRUE(tv)) {
return 1.0;
}
return 0.0;
}
case DUK_TAG_STRING: {
duk_hstring *h = DUK_TVAL_GET_STRING(tv);
duk_push_hstring(ctx, h);
return duk__tonumber_string_raw(thr);
}
case DUK_TAG_OBJECT: {
/* Note: ToPrimitive(object,hint) == [[DefaultValue]](object,hint),
* so use [[DefaultValue]] directly.
*/
duk_double_t d;
duk_push_tval(ctx, tv);
duk_to_defaultvalue(ctx, -1, DUK_HINT_NUMBER); /* 'tv' becomes invalid */
/* recursive call for a primitive value (guaranteed not to cause second
* recursion).
*/
d = duk_js_tonumber(thr, duk_require_tval(ctx, -1));
duk_pop(ctx);
return d;
}
case DUK_TAG_BUFFER: {
/* Coerce like a string. This makes sense because addition also treats
* buffers like strings.
*/
duk_hbuffer *h = DUK_TVAL_GET_BUFFER(tv);
duk_push_hbuffer(ctx, h);
duk_to_string(ctx, -1); /* XXX: expensive, but numconv now expects to see a string */
return duk__tonumber_string_raw(thr);
}
case DUK_TAG_POINTER: {
/* Coerce like boolean */
void *p = DUK_TVAL_GET_POINTER(tv);
return (p != NULL ? 1.0 : 0.0);
}
case DUK_TAG_LIGHTFUNC: {
/* +(function(){}) -> NaN */
return DUK_DOUBLE_NAN;
}
#if defined(DUK_USE_FASTINT)
case DUK_TAG_FASTINT:
return (duk_double_t) DUK_TVAL_GET_FASTINT(tv);
#endif
default: {
/* number */
DUK_ASSERT(DUK_TVAL_IS_DOUBLE(tv));
return DUK_TVAL_GET_DOUBLE(tv);
}
}
DUK_UNREACHABLE();
}
