duplicates

platform/util/src/com/intellij/openapi/util/text/CharSequenceWithStringHash.java

@@ -15,7 +15,8 @@
  */
 package com.intellij.openapi.util.text;
 
-/** This interface implementations must have hashCode values equals those for String
+/**
+ * This interface implementations must have hashCode values equal to those for String
  * @see com.intellij.openapi.util.text.StringUtil#stringHashCode(CharSequence)  
  */
 public interface CharSequenceWithStringHash extends CharSequence{

platform/util/src/com/intellij/openapi/util/text/StringUtil.java

@@ -800,12 +800,7 @@ public class StringUtil {
     if (chars instanceof CharSequenceWithStringHash) return chars.hashCode();
     if (chars instanceof CharArrayCharSequence) return chars.hashCode();
 
-    int h = 0;
-    int to = chars.length();
-    for (int off = 0; off < to; off++) {
-      h = 31 * h + chars.charAt(off);
-    }
-    return h;
+    return stringHashCode(chars, 0, chars.length());
   }
 
   public static int stringHashCode(CharSequence chars, int from, int to) {
@@ -841,12 +836,7 @@ public class StringUtil {
   }
 
   public static int stringHashCodeInsensitive(@NotNull CharSequence chars) {
-    int h = 0;
-    final int len = chars.length();
-    for (int i = 0; i < len; i++) {
-      h = 31 * h + toLowerCase(chars.charAt(i));
-    }
-    return h;
+    return stringHashCodeInsensitive(chars, 0, chars.length());
   }
 
   /**
@@ -1946,12 +1936,7 @@ public class StringUtil {
   }
 
   public static int hashCode(@NotNull CharSequence s) {
-    int result = 0;
-    for (int i = 0; i < s.length(); i++) {
-      // Copied from java.lang.String.hashCode()
-      result = 31 * result + s.charAt(i);
-    }
-    return result;
+    return stringHashCode(s);
   }
 
   public static boolean equals(@Nullable CharSequence s1, @Nullable CharSequence s2) {

platform/util/src/com/intellij/util/text/CharArrayCharSequence.java

@@ -15,6 +15,8 @@
  */
 package com.intellij.util.text;
 
+import com.intellij.openapi.util.text.StringUtil;
+
 public class CharArrayCharSequence implements CharSequenceBackedByArray {
   private final char[] myChars;
   private final int myStart;
@@ -59,12 +61,7 @@ public class CharArrayCharSequence implements CharSequenceBackedByArray {
   }
 
   public int hashCode() {
-    int h = 0;
-    int to = myEnd;
-    for (int off = myStart; off < to; off++) {
-      h = 31 * h + myChars[off];
-    }
-    return h;
+    return StringUtil.stringHashCode(myChars, myStart, myEnd);
   }
 
   public void getChars(char[] dst, int dstOffset) {