# HG changeset patch
# User Adam Chlipala <adamc@hcoop.net>
# Date 1267541177 18000
# Node ID 9df124fcab3d050df25ae46393a0f730e6a5a3eb
# Parent  983d9b38abc74db895994febbdee18d4d061ef7f
String.isPrefix

diff -r 983d9b38abc7 -r 9df124fcab3d lib/ur/string.ur
--- a/lib/ur/string.ur	Sun Feb 28 15:46:41 2010 -0500
+++ b/lib/ur/string.ur	Tue Mar 02 09:46:17 2010 -0500
@@ -53,3 +53,6 @@
     case split s #"\n" of
         None => cdata s
       | Some (s1, s2) => <xml>{[s1]}<br/>{newlines s2}</xml>
+
+fun isPrefix {Full = f, Prefix = p} =
+    length f >= length p && substring f {Start = 0, Len = length p} = p
diff -r 983d9b38abc7 -r 9df124fcab3d lib/ur/string.urs
--- a/lib/ur/string.urs	Sun Feb 28 15:46:41 2010 -0500
+++ b/lib/ur/string.urs	Tue Mar 02 09:46:17 2010 -0500
@@ -23,3 +23,5 @@
 val mp : (char -> char) -> string -> string
 
 val newlines : ctx ::: {Unit} -> [[Body] ~ ctx] => string -> xml ([Body] ++ ctx) [] []
+
+val isPrefix : {Full : t, Prefix : t} -> bool