Mercurial Mercurial > repos > isabelle / annotate
summary | shortlog | changelog | graph | tags | bookmarks | branches | files | changeset | file | latest | revisions | annotate | diff | comparison | raw | help
Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
doc-src/Tutorial/Datatype/lookup
author paulson
Fri, 19 Mar 2004 10:48:22 +0100
changeset 14475 aa973ba84f69
parent 5851 15ce4c1c8313
permissions -rw-r--r--
new thms
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
5851
15ce4c1c8313 New section on advanced datatypes.
nipkow
parents:
diff changeset 
     1
 
consts   lookup :: ('a,'v)trie => 'a list => 'v option
15ce4c1c8313 New section on advanced datatypes.
nipkow
parents:
diff changeset 
     2
 
primrec "lookup t [] = value t"
15ce4c1c8313 New section on advanced datatypes.
nipkow
parents:
diff changeset 
     3
 
        "lookup t (a#as) = (case assoc (alist t) a of
15ce4c1c8313 New section on advanced datatypes.
nipkow
parents:
diff changeset 
     4
 
                              None => None
15ce4c1c8313 New section on advanced datatypes.
nipkow
parents:
diff changeset 
     5
 
                            | Some at => lookup at as)"
isabelle