Info Catalog eintr: defun eintr: Writing Defuns eintr: Interactive

eintr: Install

 
 3.2 Install a Function Definition
 =================================
 
 If you are reading this inside of Info in Emacs, you can try out the
 ‘multiply-by-seven’ function by first evaluating the function definition
 and then evaluating ‘(multiply-by-seven 3)’.  A copy of the function
 definition follows.  Place the cursor after the last parenthesis of the
 function definition and type ‘C-x C-e’.  When you do this,
 ‘multiply-by-seven’ will appear in the echo area.  (What this means is
 that when a function definition is evaluated, the value it returns is
 the name of the defined function.)  At the same time, this action
 installs the function definition.
 
      (defun multiply-by-seven (number)
        "Multiply NUMBER by seven."
        (* 7 number))
 
 By evaluating this ‘defun’, you have just installed ‘multiply-by-seven’
 in Emacs.  The function is now just as much a part of Emacs as
 ‘forward-word’ or any other editing function you use.
 (‘multiply-by-seven’ will stay installed until you quit Emacs.  To
 reload code automatically whenever you start Emacs, see Installing
 Code Permanently Permanent Installation.)
 

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· Change a defun              How to change a function definition.
 

Info Catalog eintr: defun eintr: Writing Defuns eintr: Interactive