Rewrote squeeze to avoid commons-lang dependency

pom.xml

@@ -413,11 +413,6 @@
             <artifactId>commons-math</artifactId>
             <version>2.2</version>
         </dependency>
-        <dependency>
-            <groupId>commons-lang</groupId>
-            <artifactId>commons-lang</artifactId>
-            <version>2.6</version>
-        </dependency>
         <dependency> <!-- used by the compression uri feature-->
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-compress</artifactId>

src/org/rascalmpl/library/Prelude.java

@@ -69,7 +69,6 @@
 import java.util.function.Consumer;
 import java.util.regex.Pattern;
 
-import org.apache.commons.lang.CharSetUtils;
 import org.rascalmpl.debug.IRascalMonitor;
 import org.rascalmpl.exceptions.JavaCompilation;
 import org.rascalmpl.exceptions.RuntimeExceptionFactory;
@@ -3041,12 +3040,6 @@ public IString trim(IString s) {
 		return values.string(s.getValue().trim());
 	}
 
-	public IString squeeze(IString src, IString charSet) {
-		//@{http://commons.apache.org/lang/api-2.6/index.html?org/apache/commons/lang/text/package-summary.html}
-		String s = CharSetUtils.squeeze(src.getValue(), charSet.getValue());
-		return values.string(s);
-	}
-
 	public IString capitalize(IString src) {
 		StringBuilder result = new StringBuilder(src.length());
 		boolean lastWhitespace= true;

src/org/rascalmpl/library/String.rsc

@@ -519,8 +519,14 @@ import String;
 squeeze("hello", "el");
 ```
 }
-@javaClass{org.rascalmpl.library.Prelude}
-public java str squeeze(str src, str charSet);
+public str squeeze(str src, str charSet) {
+  if (charSet == "") {
+    return src;
+  }
+  return visit(src) {
+    case /<c:[<charSet>]><c>+/ => c
+  }
+}
 
 
 

src/org/rascalmpl/library/lang/rascal/tests/basic/Strings1.rsc

@@ -3,6 +3,7 @@ module lang::rascal::tests::basic::Strings1
 import String;
 import List;
 import util::Math;
+import IO;
 
 test bool subscription(str S){
   R = "";
@@ -248,6 +249,16 @@ test bool tstSplit(str S1, str S2) = areOverlapping(S1,S2) || isEmpty(S1) || isE
 
 // squeeze
 
+test bool tstSqueeze1(str S) = /<c:[a-zA-Z]><c>/ !:= squeeze(S, "a-zA-Z");
+test bool tstSqueeze2(str S) = squeeze(S, "") == S;
+test bool tstSqueeze3(str S) {
+  if (/<c:[a-zA-Z]><c>/ := S) {
+    return /<c><c>/ := squeeze(S, "0-9");
+  }
+  return true;
+}
+
+
 test bool tstStartsWith(str S1, str S2) = startsWith(S1+S2, S1);
 
 test bool tstSubstring1(str S){