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make-sorting-description

Function
Summary

Makes a sort description suitable for use in a sorted-object.

Package

capi

Signature

make-sorting-description &key type key sort reverse-sort
sort-function => sorting-description

Arguments

type

A Lisp object naming the type of sorting.

key

A function of one argument.

sort

A function of two arguments.

reverse-sort

A function of two arguments.

sort-function

A sorting function.

Description

The function make-sorting-description makes a sort description object that can be used as one of the sort-descriptions in a sorted-object such as a list-panel.

type is a name that should be unique amongst the sort-descriptions of a sorted-object.

key is a function that is passed to sort-function as its :key argument. The default value of key is identity .

sort is a predicate function that is passed to sort-function to compare pairs of items.

reverse-sort is a predicate function that is passed to sort-function for reverse sorting.

sort-function is the function that is called to actually do the sorting. Its signature is

sort-function items predicate &key key

The default value of sort-function is sort .

Example
(setq lp 
      (capi:contain 
       (make-instance 
        'capi:list-panel 
        :items '("Apple" 
                 "Orange" 
                 "Mangosteen" 
                 "Pineapple")
        :visible-min-height '(:character 5)
        :sort-descriptions 
        (list (capi:make-sorting-description 
               :type :length
               :sort 
               #'(lambda (x y) 
                   (> (length x) (length y)))
               :reverse-sort 
               #'(lambda (x y) 
                   (< (length x) (length y))))
              (capi:make-sorting-description 
               :type :alphabetic
               :sort 'string-greaterp
               :reverse-sort 'string-lessp)))))
 
(capi:sorted-object-sort-by lp :length)
 
(capi:sorted-object-sort-by lp :alphabetic)
See also

sort-object-items-by
sorted-object
sorted-object-sort-by


LispWorks CAPI Reference Manual - 17 Mar 2008

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