/** Type-munging for field setting and method invocation. Conforms to LC3 specification */
static Object coerceTypeImpl(Class<?> type, Object value) {
if (value != null && value.getClass() == type) {
return value;
}
switch (getJSTypeCode(value)) {
case JSTYPE_NULL:
// raise error if type.isPrimitive()
if (type.isPrimitive()) {
reportConversionError(value, type);
}
return null;
case JSTYPE_UNDEFINED:
if (type == ScriptRuntime.StringClass || type == ScriptRuntime.ObjectClass) {
return "undefined";
} else {
reportConversionError("undefined", type);
}
break;
case JSTYPE_BOOLEAN:
// Under LC3, only JS Booleans can be coerced into a Boolean value
if (type == Boolean.TYPE
|| type == ScriptRuntime.BooleanClass
|| type == ScriptRuntime.ObjectClass) {
return value;
} else if (type == ScriptRuntime.StringClass) {
return value.toString();
} else {
reportConversionError(value, type);
}
break;
case JSTYPE_NUMBER:
if (type == ScriptRuntime.StringClass) {
return ScriptRuntime.toString(value);
} else if (type == ScriptRuntime.ObjectClass) {
return coerceToNumber(Double.TYPE, value);
} else if ((type.isPrimitive() && type != Boolean.TYPE)
|| ScriptRuntime.NumberClass.isAssignableFrom(type)) {
return coerceToNumber(type, value);
} else {
reportConversionError(value, type);
}
break;
case JSTYPE_STRING:
if (type == ScriptRuntime.StringClass || type.isInstance(value)) {
return value;
} else if (type == Character.TYPE || type == ScriptRuntime.CharacterClass) {
// Special case for converting a single char string to a
// character
// Placed here because it applies *only* to JS strings,
// not other JS objects converted to strings
if (((String) value).length() == 1) {
return new Character(((String) value).charAt(0));
} else {
return coerceToNumber(type, value);
}
} else if ((type.isPrimitive() && type != Boolean.TYPE)
|| ScriptRuntime.NumberClass.isAssignableFrom(type)) {
return coerceToNumber(type, value);
} else {
reportConversionError(value, type);
}
break;
case JSTYPE_JAVA_CLASS:
if (value instanceof Wrapper) {
value = ((Wrapper) value).unwrap();
}
if (type == ScriptRuntime.ClassClass || type == ScriptRuntime.ObjectClass) {
return value;
} else if (type == ScriptRuntime.StringClass) {
return value.toString();
} else {
reportConversionError(value, type);
}
break;
case JSTYPE_JAVA_OBJECT:
case JSTYPE_JAVA_ARRAY:
if (value instanceof Wrapper) {
value = ((Wrapper) value).unwrap();
}
if (type.isPrimitive()) {
if (type == Boolean.TYPE) {
reportConversionError(value, type);
}
return coerceToNumber(type, value);
} else {
if (type == ScriptRuntime.StringClass) {
return value.toString();
} else {
if (type.isInstance(value)) {
return value;
} else {
reportConversionError(value, type);
}
}
}
break;
case JSTYPE_OBJECT:
if (type == ScriptRuntime.StringClass) {
return ScriptRuntime.toString(value);
} else if (type.isPrimitive()) {
if (type == Boolean.TYPE) {
reportConversionError(value, type);
}
return coerceToNumber(type, value);
} else if (type.isInstance(value)) {
return value;
} else if (type == ScriptRuntime.DateClass && value instanceof NativeDate) {
double time = ((NativeDate) value).getJSTimeValue();
// XXX: This will replace NaN by 0
return new Date((long) time);
} else if (type.isArray() && value instanceof NativeArray) {
// Make a new java array, and coerce the JS array components
// to the target (component) type.
NativeArray array = (NativeArray) value;
long length = array.getLength();
Class<?> arrayType = type.getComponentType();
Object Result = Array.newInstance(arrayType, (int) length);
for (int i = 0; i < length; ++i) {
try {
Array.set(Result, i, coerceType(arrayType, array.get(i, array)));
} catch (EvaluatorException ee) {
reportConversionError(value, type);
}
}
return Result;
} else if (value instanceof Wrapper) {
value = ((Wrapper) value).unwrap();
if (type.isInstance(value)) return value;
reportConversionError(value, type);
} else if (type.isInterface() && value instanceof Callable) {
// Try to use function as implementation of Java interface.
//
// XXX: Currently only instances of ScriptableObject are
// supported since the resulting interface proxies should
// be reused next time conversion is made and generic
// Callable has no storage for it. Weak references can
// address it but for now use this restriction.
if (value instanceof ScriptableObject) {
ScriptableObject so = (ScriptableObject) value;
Object key = Kit.makeHashKeyFromPair(COERCED_INTERFACE_KEY, type);
Object old = so.getAssociatedValue(key);
if (old != null) {
// Function was already wrapped
return old;
}
Context cx = Context.getContext();
Object glue = InterfaceAdapter.create(cx, type, (Callable) value);
// Store for later retrival
glue = so.associateValue(key, glue);
return glue;
}
reportConversionError(value, type);
} else {
reportConversionError(value, type);
}
break;
}
return value;
}
/**
* Derive a ranking based on how "natural" the conversion is. The special value CONVERSION_NONE
* means no conversion is possible, and CONVERSION_NONTRIVIAL signals that more type conformance
* testing is required. Based on <a
* href="http://www.mozilla.org/js/liveconnect/lc3_method_overloading.html">"preferred method
* conversions" from Live Connect 3</a>
*/
static int getConversionWeight(Object fromObj, Class<?> to) {
int fromCode = getJSTypeCode(fromObj);
switch (fromCode) {
case JSTYPE_UNDEFINED:
if (to == ScriptRuntime.StringClass || to == ScriptRuntime.ObjectClass) {
return 1;
}
break;
case JSTYPE_NULL:
if (!to.isPrimitive()) {
return 1;
}
break;
case JSTYPE_BOOLEAN:
// "boolean" is #1
if (to == Boolean.TYPE) {
return 1;
} else if (to == ScriptRuntime.BooleanClass) {
return 2;
} else if (to == ScriptRuntime.ObjectClass) {
return 3;
} else if (to == ScriptRuntime.StringClass) {
return 4;
}
break;
case JSTYPE_NUMBER:
if (to.isPrimitive()) {
if (to == Double.TYPE) {
return 1;
} else if (to != Boolean.TYPE) {
return 1 + getSizeRank(to);
}
} else {
if (to == ScriptRuntime.StringClass) {
// native numbers are #1-8
return 9;
} else if (to == ScriptRuntime.ObjectClass) {
return 10;
} else if (ScriptRuntime.NumberClass.isAssignableFrom(to)) {
// "double" is #1
return 2;
}
}
break;
case JSTYPE_STRING:
if (to == ScriptRuntime.StringClass) {
return 1;
} else if (to.isInstance(fromObj)) {
return 2;
} else if (to.isPrimitive()) {
if (to == Character.TYPE) {
return 3;
} else if (to != Boolean.TYPE) {
return 4;
}
}
break;
case JSTYPE_JAVA_CLASS:
if (to == ScriptRuntime.ClassClass) {
return 1;
} else if (to == ScriptRuntime.ObjectClass) {
return 3;
} else if (to == ScriptRuntime.StringClass) {
return 4;
}
break;
case JSTYPE_JAVA_OBJECT:
case JSTYPE_JAVA_ARRAY:
Object javaObj = fromObj;
if (javaObj instanceof Wrapper) {
javaObj = ((Wrapper) javaObj).unwrap();
}
if (to.isInstance(javaObj)) {
return CONVERSION_NONTRIVIAL;
}
if (to == ScriptRuntime.StringClass) {
return 2;
} else if (to.isPrimitive() && to != Boolean.TYPE) {
return (fromCode == JSTYPE_JAVA_ARRAY) ? CONVERSION_NONE : 2 + getSizeRank(to);
}
break;
case JSTYPE_OBJECT:
// Other objects takes #1-#3 spots
if (to == fromObj.getClass()) {
// No conversion required
return 1;
}
if (to.isArray()) {
if (fromObj instanceof NativeArray) {
// This is a native array conversion to a java array
// Array conversions are all equal, and preferable to object
// and string conversion, per LC3.
return 1;
}
} else if (to == ScriptRuntime.ObjectClass) {
return 2;
} else if (to == ScriptRuntime.StringClass) {
return 3;
} else if (to == ScriptRuntime.DateClass) {
if (fromObj instanceof NativeDate) {
// This is a native date to java date conversion
return 1;
}
} else if (to.isInterface()) {
if (fromObj instanceof Function) {
// See comments in coerceType
if (to.getMethods().length == 1) {
return 1;
}
}
return 11;
} else if (to.isPrimitive() && to != Boolean.TYPE) {
return 3 + getSizeRank(to);
}
break;
}
return CONVERSION_NONE;
}
