The generic function map-collection-items calls a specified function on all the items in a collection.
capi
map-collection-items collection function &optional collect-results-p
| collection⇩ | 
A collection. | 
| function⇩ | 
A function designator for a function of one argument. | 
| collect-results-p⇩ | 
A generalized boolean. | 
Calls function on each item in collection by calling collection's items-map-function. If collect-results-p is true, the results of these calls are returned in a list.
(setq collection (make-instance 'capi:collection
                                :items '(1 2 3 4 5)))
(capi:map-collection-items collection 
                           'princ-to-string t)
CAPI User Guide and Reference Manual (Unix version) - 01 Dec 2021 19:32:42