decf/delete-acons |
| item decrement place
&key key test test-not | [Macro] |
Purpose
Decrement by
Package :gbbopen-tools
Module :gbbopen-tools
Arguments and values
item | An object | |
decrement | A number | |
place | A form which is suitable for use as a generalized reference | |
key | A function designator specifying a function object
of one argument, or nil (default is nil )
| |
test | A function designator specifying a function object
of two arguments that returns a generalized boolean (default is
#'eql | |
test-not | A function designator specifying a
function object of two arguments that returns a
generalized boolean (use of :test-not | |
new-place-value | An association list |
Returns
An association list (the new value of place).
Errors
Item item is not present in the association list
stored in place.
Description
This is the inverse of
See also
pushnew/incf-acons
Examples
> (setf alist '((x . 2)(y . 2)) ((x . 2)(y . 2)) > (decf/delete-acons 'x 1 alist) ((x . 1)(y . 2)) > (decf/delete-acons 'x 1 alist) ((y . 2)) > (decf/delete-acons 'y 2 alist) nil >
Note
Declared numeric and pseudo
probability versions of
The GBBopen Project
decf/delete-acons |