Method keywords

Method Keywords

__c_arg__

Treat the next method argument as a C argument. See Method functions.

classMethod

The classMethod keyword declares a method, as described above.

classVariable

Adds a class variable definition to a class. This method needs to be used globally, when a class is declared. The syntax is:

parent_class classVariable name [native_class|typecast_expr] [initial_value] [docstring] ;

For example:

FileStream class ReadFileStream;

...

ReadFileStream classVariable stdinStream Symbol 0x0;

The value of initial_value can be either a constant or an expression that evaluates to a constant.

Ctalk can also translate a typecast into a native class for the variable. Also refer to the entry for instanceVariable, below. See InstanceVariableKeyword.

Similarly, the docString element is also optional. See VariableDocStrings.

eval

Do not try to evaluate the following statement until run time. Methods can use this keyword if they need to wait until run time to determine an receiver’s class and are not able to alias the object or otherwise inform the front end of the receiver’s class before the program is run.

instanceMethod

The instanceMethod keyword declares a method, as described above.

instanceVariable

Adds an instance variable definition to a class. This method needs be used when the class is declared. The syntax is:

parent_class instanceVariable name [native_class|typecast_expr] [initial_value] [docString] ;

For example:

FileStream class ReadFileStream;
ReadFileStream instanceVariable pos LongInteger 0L;

The value of initial_value can be either a constant or an expression that evaluates to a constant.

You can also use a typecast in place of the variable’s native_class. Ctalk can translate most builtin C types or typedefs to a class, but for less common data types, Ctalk will translate a pointer to the type as a Symbol object.

Similarly, the docString element is also optional. See VariableDocStrings.

Note that the instanceVariable method does not create any variables. Ctalk only creates instance variables for each object when it receives a constructor message (e.g., new) by a program.

noMethodInit

Do not include method initialization code for the method. See Method functions.

require

Require a class to be loaded before any other classes or methods.

returnObjectClass

Set the return class of a method to the argument if it is different than the receiver class. See Return values.

self

Return the method’s receiver object. In version 0.66 2021-02-02, you can also use self in arguments as a synonym for the receiver of the statement, as in this example.

String new path;
path = "/home/user/joe";

printf ("%s", path subString 1, self length - 1);

The use of self in method arguments is experimental in version 0.66 2021-02-02, and it should be used with caution.

super

The keyword super has two different meanings. It can modify a method, as in the following example.

MyReceiverClass super new instanceObject;

super can also represent the receiver’s superclass object, so it can appear as a receiver, as in this example.

return super new checksum;