Implementation of vlists, a functional list-like data structure.
The vlist library provides an implementations of vlists, a functional list-like data structure described by Phil Bagwell in "Fast Functional Lists, Hash-Lists, Dequeues and Variable-Length Arrays", EPFL Technical Report, 2002.
The idea is to store vlist elements in increasingly large contiguous blocks (implemented as vectors here). These blocks are linked to one another using a pointer to the next block (called `block-base' here) and an offset within that block (`block-offset' here). The size of these blocks form a geometric series with ratio `block-growth-factor'.
In the best case (e.g., using a vlist returned by `list->vlist'), elements from the first half of an N-element vlist are accessed in O(1) (assuming `block-growth-factor' is 2), and `vlist-length' takes only O(ln(N)). Furthermore, the data structure improves data locality since vlist elements are adjacent, which plays well with caches.
Returns #t if x is a vlist, #f otherwise.
Creates a new vlist with item as its head and vlist as its tail.
Returns the head of vlist.
Return the tail of vlist.
Returns true if vlist is empty, false otherwise.
Returns a new vlist whose contents correspond to lst.
Fold over vlist, calling proc for each element.
Fold over vlist, calling proc for each element, starting from the last element.
Returns a new vlist whose content are those of vlist in reverse order.
Maps proc over the elements of vlist and return a new vlist.
Return a new list containing the elements of vlist.
Returns the element at index index in vlist.
Returns a new vlist that does not contain the count first elements of vlist.
Returns a new vlist that contains only the count first elements of vlist.
Returns a new vlist containing all the elements from vlist that satisfy pred.
Returns a new vlist corresponding to vlist without the elements equal? to x.
Returns the length of vlist.
vlist constructor. Analogous to SRFI-1 `unfold'.
vlist constructor. Analogous to SRFI-1 `unfold-right'.
Appends the given vlists.
Calls proc on each element of vlist.
Hash vlists are analogous to association lists.
Returns true if obj is a hash vlist, false otherwise.
Return a new hash list based on vhash where key is associated with value. Use hash to compute key's hash.
Folds over all the values associated with key in vhash, with each call to proc having the form (proc value result), where result is the result of the previous call to proc and init the value of result for the first call to proc.
Returns the first key/value pair from vhash whose key is equal to key according to the equal? equality predicate.
Returns the first key/value pair from vhash whose key is eq? to key.
Returns the first key/value pair from vhash whose key is eqv? to key.
Removes all associations from vhash with key, comparing keys with equal?.
Folds over the key/pair elements of vhash from left to right, with each call to proc having the form (proc key value result), where result is the result of the previous call to proc and init the value of result for the first call to proc.
Folds over the key/pair elements of vhash from right to left, with each call to proc having the form (proc key value result), where result is the result of the previous call to proc and init the value of result for the first call to proc.
Returns the vhash corresponding to alist, an association list.
- Ported to CHICKEN 5 (thanks to Yuriy Shirokov)
- Initial release
The vlist library was written by Ludovic Courtès and adapted for Chicken Scheme by Ivan Raikov. Copyright (C) 2009, 2010, 2011, 2012 Free Software Foundation, Inc. Chicken Scheme modifications Copyright 2012 Ivan Raikov. This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. A full copy of the Lesser GPL license can be found at <http://www.gnu.org/licenses/>.