Mercurial > urweb
view src/list_util.sml @ 95:274116d1a4cd
Monoizing joins and tags
author | Adam Chlipala <adamc@hcoop.net> |
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date | Thu, 03 Jul 2008 17:53:28 -0400 |
parents | 02f42e9a1825 |
children | 3739af9e727a |
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(* Copyright (c) 2008, Adam Chlipala * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * - Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * - The names of contributors may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. *) structure ListUtil :> LIST_UTIL = struct structure S = Search fun mapfold f = let fun mf ls s = case ls of nil => S.Continue (nil, s) | h :: t => case f h s of S.Return x => S.Return x | S.Continue (h', s) => case mf t s of S.Return x => S.Return x | S.Continue (t', s) => S.Continue (h' :: t', s) in mf end fun mapfoldB f = let fun mf ctx ls s = case ls of nil => S.Continue (nil, s) | h :: t => let val (ctx, r) = f (ctx, h) in case r s of S.Return x => S.Return x | S.Continue (h', s) => case mf ctx t s of S.Return x => S.Return x | S.Continue (t', s) => S.Continue (h' :: t', s) end in mf end fun foldlMap f s = let fun fm (ls', s) ls = case ls of nil => (rev ls', s) | h :: t => let val (h', s') = f (h, s) in fm (h' :: ls', s') t end in fm ([], s) end fun foldlMapConcat f s = let fun fm (ls', s) ls = case ls of nil => (rev ls', s) | h :: t => let val (h', s') = f (h, s) in fm (List.revAppend (h', ls'), s') t end in fm ([], s) end fun foldlMapPartial f s = let fun fm (ls', s) ls = case ls of nil => (rev ls', s) | h :: t => let val (h', s') = f (h, s) val ls' = case h' of NONE => ls' | SOME h' => h' :: ls' in fm (ls', s') t end in fm ([], s) end fun search f = let fun s ls = case ls of [] => NONE | h :: t => case f h of NONE => s t | v => v in s end end