;;;; -*- Mode: Lisp; indent-tabs-mode: nil -*-
;;;
;;; SPLIT-SEQUENCE
;;;
;;; This code was based on Arthur Lemmens' in
;;; <URL:http://groups.google.com/groups?as_umsgid=39F36F1A.B8F19D20%40simplex.nl>;
;;;
;;; changes include:
;;;
;;; * altering the behaviour of the :from-end keyword argument to
;;; return the subsequences in original order, for consistency with
;;; CL:REMOVE, CL:SUBSTITUTE et al. (:from-end being non-NIL only
;;; affects the answer if :count is less than the number of
;;; subsequences, by analogy with the above-referenced functions).
;;;
;;; * changing the :maximum keyword argument to :count, by analogy
;;; with CL:REMOVE, CL:SUBSTITUTE, and so on.
;;;
;;; * naming the function SPLIT-SEQUENCE rather than PARTITION rather
;;; than SPLIT.
;;;
;;; * adding SPLIT-SEQUENCE-IF and SPLIT-SEQUENCE-IF-NOT.
;;;
;;; * The second return value is now an index rather than a copy of a
;;; portion of the sequence; this index is the `right' one to feed to
;;; CL:SUBSEQ for continued processing.

;;; There's a certain amount of code duplication in the vector and
;;; extended sequence modules, which is kept to illustrate the
;;; relationship between the SPLIT-SEQUENCE functions and the
;;; CL:POSITION functions.

(defpackage #:split-sequence
  (:use #:common-lisp)
  (:export #:split-sequence
           #:split-sequence-if
           #:split-sequence-if-not))