From 1195d9ce07d2e4f2d4c2a7d67dc0bd657556e2c7 Mon Sep 17 00:00:00 2001
From: Svjatoslav Agejenko <svjatoslav@svjatoslav.eu>
Date: Fri, 13 Oct 2017 12:36:11 +0300
Subject: [PATCH] Improved suffix and prefix handling in String2.

---
 .../eu/svjatoslav/commons/string/String2.java | 62 ++++++++++++++++---
 .../commons/string/String2Test.java           | 22 +++++--
 2 files changed, 70 insertions(+), 14 deletions(-)

diff --git a/src/main/java/eu/svjatoslav/commons/string/String2.java b/src/main/java/eu/svjatoslav/commons/string/String2.java
index 113f67e..504c41d 100755
--- a/src/main/java/eu/svjatoslav/commons/string/String2.java
+++ b/src/main/java/eu/svjatoslav/commons/string/String2.java
@@ -9,21 +9,23 @@
 
 package eu.svjatoslav.commons.string;
 
-import java.util.Vector;
+import java.util.ArrayList;
+import java.util.List;
 
 public class String2 {
 
-    private final Vector<Character> chars = new Vector<>();
+    private final List<Character> chars;
 
     public String2(final String value) {
+        chars = new ArrayList<>(value.length());
         for (final Character c : value.toCharArray())
             chars.add(c);
     }
 
     public String2 addPrefix(final String prefix) {
-        int j = 0;
+        int i = 0;
         for (final char c : prefix.toCharArray())
-            chars.insertElementAt(c, j++);
+            chars.add(i++, c);
 
         return this;
     }
@@ -41,18 +43,62 @@ public class String2 {
      * @param cutAmount of characters to cut
      * @return part that was cut.
      */
-    public String trimLeft(final int cutAmount) {
+    public String2 trimPrefix(final int cutAmount) {
 
         int actualCutAmount = cutAmount;
 
         if (actualCutAmount > getLength())
             actualCutAmount = getLength();
 
-        final String result = getSubString(0, actualCutAmount);
-
         chars.subList(0, actualCutAmount).clear();
 
-        return result;
+        return this;
+    }
+
+    public String2 trimPrefixIfExists(String prefix){
+        if (hasPrefix(prefix))
+            trimPrefix(prefix.length());
+
+        return this;
+    }
+
+    public String2 trimSuffixIfExists(String suffix){
+        if (hasSuffix(suffix))
+            trimSuffix(suffix.length());
+
+        return this;
+    }
+
+    public String2 trimSuffix(int charsToTrim) {
+
+        if (charsToTrim > chars.size()){
+            chars.clear();
+            return this;
+        }
+
+        for (int i = 0; i<charsToTrim; i++)
+            chars.remove(chars.size()-1);
+
+        return this;
+    }
+
+    public boolean hasSuffix(String suffix) {
+        return contains(suffix, getLength() - suffix.length());
+    }
+
+    public boolean hasPrefix(String prefix){
+        return contains(prefix, 0);
+    }
+
+    public boolean contains(String fragment, int index){
+        if (index + fragment.length() > chars.size())
+            return false;
+
+        for (int i = 0; i < fragment.length(); i++)
+            if (chars.get(index + i) != fragment.charAt(i))
+                return false;
+
+        return true;
     }
 
     public String2 enforceLength(final int targetLength) {
diff --git a/src/test/java/eu/svjatoslav/commons/string/String2Test.java b/src/test/java/eu/svjatoslav/commons/string/String2Test.java
index 35e203b..adc14a8 100755
--- a/src/test/java/eu/svjatoslav/commons/string/String2Test.java
+++ b/src/test/java/eu/svjatoslav/commons/string/String2Test.java
@@ -16,18 +16,28 @@ import static org.junit.Assert.assertEquals;
 public class String2Test {
 
     @Test
-    public void testCutLeft() {
+    public void testTrimPrefix() {
 
         final String2 s = new String2("this is a test");
 
-        assertEquals("this ", s.trimLeft(5));
-        assertEquals("is ", s.trimLeft(3));
-        assertEquals("a ", s.trimLeft(2));
-        assertEquals("test", s.trimLeft(25));
-        assertEquals("", s.trimLeft(5));
+        assertEquals("is a test", s.trimPrefix(5).toString());
+        assertEquals("a test", s.trimPrefix(3).toString());
+        assertEquals("test", s.trimPrefix(2).toString());
+        assertEquals("", s.trimPrefix(500).toString());
+    }
+
+    @Test
+    public void testTrimSuffix() {
 
+        final String2 s = new String2("this is a test");
+
+        assertEquals("this is a", s.trimSuffix(5).toString());
+        assertEquals("this is", s.trimSuffix(2).toString());
+        assertEquals("this", s.trimSuffix(3).toString());
+        assertEquals("", s.trimSuffix(500).toString());
     }
 
+
     @Test
     public void testEnforceLength() {
         final String2 s = new String2("12345678");
-- 
2.20.1