--- a/src/luan/modules/StringLuan.java	Sat Jul 23 21:53:04 2022 -0600
+++ b/src/luan/modules/StringLuan.java	Sun Jul 24 23:43:03 2022 -0600
@@ -92,14 +92,13 @@
 		return s.substring(start,end);
 	}
 
-	public static Object[] find(String s,Object pattern,Integer init,Boolean plain) throws LuanException {
+	public static Object[] find(String s,String pattern,Integer init,Boolean plain) {
 		int start = start(s,init,0);
 		if( Boolean.TRUE.equals(plain) ) {
-			String ptn = (String)pattern;
-			int i = s.indexOf(ptn,start);
-			return i == -1 ? null : new Integer[]{i+1,i+ptn.length()};
+			int i = s.indexOf(pattern,start);
+			return i == -1 ? null : new Integer[]{i+1,i+pattern.length()};
 		}
-		Matcher m = pattern(pattern).matcher(s);
+		Matcher m = Pattern.compile(pattern).matcher(s);
 		if( !m.find(start) )
 			return null;
 		int n = m.groupCount();
@@ -112,9 +111,9 @@
 		return rtn;
 	}
 
-	public static String[] match(String s,Object pattern,Integer init) throws LuanException {
+	public static String[] match(String s,String pattern,Integer init) {
 		int start = start(s,init,0);
-		Matcher m = pattern(pattern).matcher(s);
+		Matcher m = Pattern.compile(pattern).matcher(s);
 		if( !m.find(start) )
 			return null;
 		int n = m.groupCount();
@@ -127,9 +126,10 @@
 		return rtn;
 	}
 
-	public static LuanFunction gmatch(String s,Object pattern) throws LuanException {
+	public static LuanFunction gmatch(String s,String pattern) throws LuanException {
 		Utils.checkNotNull(s);
-		final Matcher m = pattern(pattern).matcher(s);
+		Utils.checkNotNull(pattern,2);
+		final Matcher m = Pattern.compile(pattern).matcher(s);
 		return new LuanFunction() {
 			@Override public Object call(Luan luan,Object[] args) {
 				if( !m.find() )
@@ -146,10 +146,10 @@
 		};
 	}
 
-	public static Object[] gsub(Luan luan,String s,Object pattern,Object repl,Integer n) throws LuanException {
+	public static Object[] gsub(Luan luan,String s,String pattern,Object repl,Integer n) throws LuanException {
 		Utils.checkNotNull(s);
 		int max = n==null ? Integer.MAX_VALUE : n;
-		final Matcher m = pattern(pattern).matcher(s);
+		final Matcher m = Pattern.compile(pattern).matcher(s);
 		if( repl instanceof String ) {
 			String replacement = (String)repl;
 			int i = 0;
@@ -226,24 +226,14 @@
 		return null;
 	}
 
-	private static Pattern pattern(Object pattern) throws LuanException {
-		if( pattern instanceof Pattern ) {
-			return (Pattern)pattern;
-		} else if( pattern instanceof String ) {
-			return Pattern.compile((String)pattern);
-		} else {
-			throw new LuanException( "bad argument #2 (string or compiled pattern expected)" );
-		}
-	}
-
-	public static boolean matches(String s,Object pattern) throws LuanException {
+	public static boolean matches(String s,String pattern) throws LuanException {
 		Utils.checkNotNull(s);
-		return pattern(pattern).matcher(s).find();
+		return Pattern.compile(pattern).matcher(s).find();
 	}
 
 	public static String[] split(String s,String pattern,Integer limit) throws LuanException {
 		Utils.checkNotNull(s);
-		Utils.checkNotNull(pattern,1);
+		Utils.checkNotNull(pattern,2);
 		int n = limit==null ? -1 : limit;
 		return s.split(pattern,n);
 	}
@@ -254,4 +244,22 @@
 		return BinaryLuan.to_hex( BinaryLuan.digest_message( algorithm, input.getBytes() ) );
 	}
 
+	public static boolean contains(String s,String s2) throws LuanException {
+		Utils.checkNotNull(s);
+		Utils.checkNotNull(s2,2);
+		return s.contains(s2);
+	}
+
+	public static boolean starts_with(String s,String s2) throws LuanException {
+		Utils.checkNotNull(s);
+		Utils.checkNotNull(s2,2);
+		return s.startsWith(s2);
+	}
+
+	public static boolean ends_with(String s,String s2) throws LuanException {
+		Utils.checkNotNull(s);
+		Utils.checkNotNull(s2,2);
+		return s.endsWith(s2);
+	}
+
 }