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ANSI Common Lisp  5 Data and Control Flow 5.3 Dictionary of Data and Control Flow
| 5.3.17 destructuring-bind |
Macro |
- Syntax:
-
destructuring-bind
lambda-list expression {declaration}* {form}*
 {result}*
- Arguments and Values:
-
lambda-list - a destructuring lambda list.
expression - a form.
declaration - a declare expression; not evaluated.
forms - an implicit progn.
results - the values returned by the forms.
- Description:
-
destructuring-bind binds the variables specified in lambda-list
to the corresponding values in the tree structure resulting from the evaluation
of expression; then destructuring-bind evaluates forms.
The lambda-list supports destructuring as described in
Section 3.4.5 Destructuring Lambda Lists.
- Examples:
-
(defun iota (n) (loop for i from 1 to n collect i)) ;helper
(destructuring-bind ((a &optional (b 'bee)) one two three)
`((alpha) ,@(iota 3))
(list a b three two one)) (ALPHA BEE 3 2 1)
- Exceptional Situations:
-
If the result of evaluating the expression does not match the
destructuring pattern, an error of type error should be signaled.
- See Also:
-
macrolet, defmacro
- Allegro CL Implementation Details:
-
None.
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