| The class file defines three methods which attach a callback function to an object of the class. This class is inherited by the socket and stream classes. The callback function will be called later on during the execution of the function select on lists of socket or stream objects. The user can defines as many callbacks as there are different instances of selectable objects, or generic functions by type of event: read, write or except. The callback may be a method of the class of the selected object, or a class-less function. In the first case, the selected object will be passed as the value of the this symbol, and in the second case it will be the argument of the function. |
| Function Type | subr |
| Arguments | an object of the file class |
| Return Value | an integer |
| Description | returns the file descriptor number of the file object; as streams and socket are file subclasses, the function is to be applied to stream or socket objects |
| Example | (fileno stdin) => 0 |
| Function Type | subr |
| Arguments | an object of the file class, a symbol or a list |
| Return Value | t or nil |
| Description | checks if the second argument is either a symbol bound to a valid function definition (interpreted or compiled) or a lambda definition or nil, and sets the 'exceptproc property to the definition; returns t in case of success. |
| Example | (set-except-proc sock 'cbf1) |
| Function Type | subr |
| Arguments | an object of the file class, a symbol or a list |
| Return Value | t or nil |
| Description | checks if the second argument is either a symbol bound to a valid function definition (interpreted or compiled) or a lambda definition or nil, and sets the 'readproc property to the definition; returns t in case of success. |
| Example | (set-read-proc sock 'cbf1) |
| Function Type | subr |
| Arguments | an object of the file class, a symbol or a list |
| Return Value | t or nil |
| Description | checks if the second argument is either a symbol bound to a valid function definition (interpreted or compiled) or a lambda definition or nil, and sets the 'writeproc property to the definition; returns t in case of success. |
| Example | (set-write-proc sock 'cbf1) |