Info Catalog elisp: Command Overview elisp: Command Loop elisp: Interactive Call

elisp: Defining Commands

 
 20.2 Defining Commands
 ======================
 
 The special form ‘interactive’ turns a Lisp function into a command.
 The ‘interactive’ form must be located at top-level in the function
 body, usually as the first form in the body; this applies to both lambda
DONTPRINTYET  expressions (Lambda Expressions) and ‘defun’ forms (*noteDONTPRINTYET  expressions (Lambda Expressions) and ‘defun’ forms (
 Defining Functions).  This form does nothing during the actual
 execution of the function; its presence serves as a flag, telling the
 Emacs command loop that the function can be called interactively.  The
 argument of the ‘interactive’ form specifies how the arguments for an
 interactive call should be read.
 
    Alternatively, an ‘interactive’ form may be specified in a function
 symbol’s ‘interactive-form’ property.  A non-‘nil’ value for this
 property takes precedence over any ‘interactive’ form in the function
 body itself.  This feature is seldom used.
 
    Sometimes, a function is only intended to be called interactively,
 never directly from Lisp.  In that case, give the function a non-‘nil’
 ‘interactive-only’ property, either directly or via ‘declare’ (
 Declare Form).  This causes the byte compiler to warn if the command
 is called from Lisp.  The output of ‘describe-function’ will include
 similar information.  The value of the property can be: a string, which
 the byte-compiler will use directly in its warning (it should end with a
 period, and not start with a capital, e.g., ‘"use (system-name)
 instead."’); ‘t’; any other symbol, which should be an alternative
 function to use in Lisp code.
 

Menu

 
· Using Interactive     General rules for ‘interactive’.
· Interactive Codes     The standard letter-codes for reading arguments
                              in various ways.
· Interactive Examples  Examples of how to read interactive arguments.
· Generic Commands      Select among command alternatives.
 

Info Catalog elisp: Command Overview elisp: Command Loop elisp: Interactive Call