doc-src/Tutorial/Datatype/lookup
author paulson
Fri, 24 Jan 2003 18:13:59 +0100
changeset 13786 ab8f39f48a6f
parent 5851 15ce4c1c8313
permissions -rw-r--r--
More conversion of UNITY to Isar new-style theories

consts   lookup :: ('a,'v)trie => 'a list => 'v option
primrec "lookup t [] = value t"
        "lookup t (a#as) = (case assoc (alist t) a of
                              None => None
                            | Some at => lookup at as)"