GBBopen 1.2 Reference -- counted-delete

counted-delete

counted-delete item sequence &key from-end test test-not start end count key => result-sequence, count [Function]

Purpose
A version of delete that returns the number of items that were deleted as a second value.

Package :gbbopen-tools

Module :gbbopen-tools

Arguments and values

item		An object
sequence		A proper sequence
from-end		A generalized boolean (default is `nil`)
test		A function of two arguments that returns a generalized boolean (default is `#'eql`)
test-not		A function of two arguments that returns a generalized boolean (use of `:test-not` is deprecated)
start		Starting index into `sequence` (default is `0`)
end		Ending index into `sequence` (default is `nil`, meaning end of `sequence`)
count		An integer or `nil` (default is `nil`)
key		A function of one argument, or `nil` (default is `nil`)
result-sequence		A sequence

Returns
Two values:

the sequence from which the elements that satisfy the test have been removed
the number of items that have been removed, or nil

Description
Returns a sequence from which elements that satisfy the test have been deleted. The supplied sequence may be modified in constructing the result; however, modification of the supplied sequence itself is not guaranteed.

Specifying a from-end value of true matters only when the count is provided, and in that case only the rightmost count elements satisfying the test are deleted.

See also
atomic-delete

Examples


  > (counted-delete 'a '(a b c a b c))
  (b c b c)
  2
  > (counted-delete #\a "abcabc")
  "bcbc"
  2
  > (counted-delete 'z '(a b c a b c))
  (a b c a b c)
  0
  > (counted-delete #\a "abcabc" :from-end 't :count 1)
  "abcbc"
  1
  >

Note
This is what delete should have been (and was on the Lisp Machines).

The GBBopen Project

counted-delete