Nyquist / XLISP 2.0  - 
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decf
  | Type: | - | Lisp macro (closure) | 
  | Source: | - | misc.lsp | 
Syntax
- (decf symbol)
- symbol - a symbol with numerical value bound to it
 returns - the new value of the symbol
 
In Nyquist, 'decf' is implemented as a Lisp macro:
(defmacro decf (symbol)
  `(setf ,symbol (1- ,symbol)))
Description
The 'decf' macro is used for decrementing a numerical value of a variable.
1 is substracted to the number and the result is stored in the
variable. An error is signalled if the variable doesn't hold a
number.
Examples
(setq n 3)    => 3
(decf n)      => 2
n             => 2
(decf n)      => 1
(setq n 1.8)  => 1.8
(decf n)      => 0.8
(decf n)      => -0.2
(decf n)      => -1.2
n             => -1.2
(setq n #\a)  => #\a
(decf a)      => error: bad argument type - #\a
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Nyquist / XLISP 2.0  - 
Contents |
Tutorials |
Examples |
Reference