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getf Conses Dictionary intersection
Macro

remf

remf place indicator ⇒ generalized-boolean

Arguments and Values

placea place.
indicatoran object.
generalized-booleana generalized boolean.

Description

remf removes from the property list stored in place a property_1 with a property indicator identical to indicator.

If there are multiple properties_1 with the identical key, remf only removes the first such property.

remf returns false if no such property was found, or true if a property was found.

The property indicator and the corresponding property value are removed in an undefined order by destructively splicing the property list.

remf is permitted to either setf place or to setf any part, car or cdr, of the list structure held by that place.

For information about the evaluation of subforms of place, see Evaluation of Subforms to Places.

Examples

 (setq x (cons () ())) ⇒  (NIL)
 (setf (getf (car x) 'prop1) 'val1) ⇒  VAL1
 (remf (car x) 'prop1) ⇒  true
 (remf (car x) 'prop1) ⇒  false

Side Effects

The property list stored in place is modified.

See Also

remprop, getf

Backlinks

Conses Dictionary, eq, Evaluation of Subforms to Places, Overview of Places and Generalized Reference, remprop, symbol, Symbols in the COMMON-LISP Package, Treatment of Other Macros Based on SETF