Object


superclass: nil


Object is the root class of all other classes. All objects are indirect instances of class Object.


Class membership:


class


Answer the class of the object.


5.class.name.postln;


respondsTo(selector)


Answer a Boolean whether the receiver understands the message selector. 

Selector must be a Symbol.


5.respondsTo('+').postln;


isKindOf(aClass)


Answer a Boolean whether the receiver is a direct or indirect instance of aClass.

Use of this message in code must be questioned, because it often indicates a missed

opportunity to exploit object polymorphism.


5.isKindOf(Magnitude).postln;


isMemberOf(aClass)


Answer a Boolean whether the receiver is a direct instance of aClass.

Use of this message in code is almost always a design mistake.


5.isMemberOf(Integer).postln;



Accessing:


size


Different classes interpret this message differently.  Object always returns 0.



Copying:


copy


Make a copy of the receiver. The implementation of this message depends on the object's class.  In class Object, copy calls shallowCopy.


shallowCopy


Makes a copy of the object. The copy's named and indexed instance variables refer to the same objects as the receiver.


deepCopy


Recursively copies the object and all of the objects contained in the instance variables, and so on down the structure. This method works with cyclic graphs.



Equality, Identity:


== anotherObject


Answer whether the receiver equals anotherObject. The definition of equality depends on the class

of the receiver. The default implementation in Object is to answer if the two objects are identical (see below).


=== anotherObject


Answer whether the receiver is the exact same object as anotherObject.


!= anotherObject


Answer whether the receiver does not equal anotherObject.

The default implementation in Object is to answer if the two objects are not identical (see below).


!== anotherObject


Answer whether the receiver is not the exact same object as anotherObject.


hash


Answer a code used to index into a hash table. This is used by Dictionaries and Sets to implement fast object lookup.  Objects which are equal == should have the same hash values. Whenever == is overridden in a class, hash should be overridden as well.


identityHash


Answer a code used to index into a hash table. This method is implemented by a primitive and is not overridden. Objects which are identical === should have the same hash values.



Testing:


isNil


Answer whether the receiver is nil.


notNil


Answer whether the receiver is not nil.


isNumber


Answer whether the receiver is an instance of Number.


isInteger


Answer whether the receiver is an instance of Integer.


isFloat


Answer whether the receiver is an instance of Float.


pointsTo(anObject)


Answer whether one of the receiver's instance variables refers to anObject.


? anObject


If the receiver is nil then answer anObject, otherwise answer the receiver.


?? aFunction


If the receiver is nil, value the function and return the result.


switch(cases)


Object implements a switch method which allows for conditional evaluation with multiple cases. These are implemented as pairs of test objects (tested using if this == test.value) and corresponding functions to be evaluated if true. In order for switch to be inlined (and thus be as efficient as nested if statements) the matching values must be literal Integers, Floats, Chars, Symbols and the functions must have no variables or arguments.


(

var x, z;

z = [0, 1, 1.1, 1.3, 1.5, 2];

switch (z.choose.postln,

1,   { \no },

1.1, { \wrong },

1.3, { \wrong },

1.5, { \wrong },

2,   { \wrong },

0,   { \true }

).postln;

)


or:

(

var x, z;

z = [0, 1, 1.1, 1.3, 1.5, 2];

x = switch (z.choose)

{1}   { \no }

{1.1} { \wrong }

{1.3} { \wrong }

{1.5} { \wrong }

{2}   { \wrong }

{0}   { \true };

x.postln;

)


Messaging:


perform(selector ... args)


The selector argument must be a Symbol.

Sends the method named by the selector with the given arguments to the receiver.


performList(selector, ...args..., listOrArray)


The selector argument must be a Symbol.

Sends the method named by the selector with the given arguments to the receiver. If the last

argument is a List or an Array, then its elements are unpacked and passed as arguments.


performMsg(listOrArray)


The argument must be a List or Array whose first element is a Symbol representing a method selector.  

The remaining elements are unpacked and passed as arguments to the method named by the selector



Printing:


post


Print a string representation of the receiver.


postln


Print a string representation of the receiver followed by a newline.


dump


Print a detailed low level representation of the receiver.



Dependancy:


addDependant(aDependant)


Add aDependant to the receiver's list of dependants.


removeDependant(aDependant)


Remove aDependant from the receiver's list of dependants.


dependants


Answer an IdentitySet of all dependants of the receiver.


changed(theChanger)


Notify the receiver's dependants that it has changed. The object making the change should be passed

as theChanger.


update(theChanged, theChanger)


An object upon which the receiver depends has changed. theChanged is the object that changed and

theChanger is the object that made the change.


release


Remove all dependants of the receiver. Any object that has had dependants added must be

released in order for it or its dependants to get garbage collected.


Routines


yield


Must be called from inside a Routine. Yields control to the calling thread. The receiver is the result

passed to the calling thread's method. The result of yield will be the value passed to the Routine's next

method the next time it is called.


yieldAndReset


Must be called from inside a Routine. Yields control to the calling thread. The receiver is the result

passed to the calling thread's method. The Routine is reset so that the next time it is called, it will

start from the beginning. yieldAndReset never returns within the Routine.


alwaysYield


Must be called from inside a Routine. Yields control to the calling thread. The receiver is the result

passed to the calling thread's method. The Routine, when called subsequently

will always yield the receiver until it is reset. alwaysYield never returns within the Routine.