[PATCH] AbstractStringBuilder.append(<StringBuilder>)

[Isaac Levy]

And can't remove append(StringBuffer) because of binary compatibility?

Isaac


On Thu, Jun 28, 2018 at 1:22 AM, Martin Buchholz <martinrb at google.com> wrote:
> I'm fairly sure the append(StringBuilder) overloads were left out
> intentionally.
>
> On Wed, Jun 27, 2018 at 8:57 PM, Isaac Levy <isaac.r.levy at gmail.com> wrote:
>>
>> AbstractStringBuilder already has append(<StringBuffer>). This patch
>> adds append(<StringBuilder>).
>>
>> The new method improves parity between the two classes. In addition,
>> combining StringBuilders is presumably common. append(<CharSequence>)
>> has a couple insteadof checks, which this new method skips.
>>
>> -Isaac
>>
>>
>>
>>
>> diff --git
>> a/src/java.base/share/classes/java/lang/AbstractStringBuilder.java
>> b/src/java.base/share/classes/java/lang/AbstractStringBuilder.java
>> index 2ef3e53256..1fe89bb92a 100644
>> --- a/src/java.base/share/classes/java/lang/AbstractStringBuilder.java
>> +++ b/src/java.base/share/classes/java/lang/AbstractStringBuilder.java
>> @@ -543,6 +543,11 @@ abstract class AbstractStringBuilder implements
>> Appendable, CharSequence {
>>          return this.append((AbstractStringBuilder)sb);
>>      }
>>
>> +    // Documentation in subclasses because of synchro difference
>> +    public AbstractStringBuilder append(StringBuilder sb) {
>> +        return this.append((AbstractStringBuilder)sb);
>> +    }
>> +
>>      /**
>>       * @since 1.8
>>       */
>> diff --git a/src/java.base/share/classes/java/lang/StringBuffer.java
>> b/src/java.base/share/classes/java/lang/StringBuffer.java
>> index e597a8112e..613ba90c25 100644
>> --- a/src/java.base/share/classes/java/lang/StringBuffer.java
>> +++ b/src/java.base/share/classes/java/lang/StringBuffer.java
>> @@ -313,6 +313,33 @@ import jdk.internal.HotSpotIntrinsicCandidate;
>>          return this;
>>      }
>>
>> +    /**
>> +     * Appends the specified {@code StringBuilder} to this sequence.
>> +     * <p>
>> +     * The characters of the {@code StringBuilder} argument are appended,
>> +     * in order, to the contents of this {@code StringBuffer}, increasing
>> the
>> +     * length of this {@code StringBuffer} by the length of the argument.
>> +     * If {@code sb} is {@code null}, then the four characters
>> +     * {@code "null"} are appended to this {@code StringBuffer}.
>> +     * <p>
>> +     * Let <i>n</i> be the length of the old character sequence, the one
>> +     * contained in the {@code StringBuffer} just prior to execution of
>> the
>> +     * {@code append} method. Then the character at index <i>k</i> in
>> +     * the new character sequence is equal to the character at index
>> <i>k</i>
>> +     * in the old character sequence, if <i>k</i> is less than <i>n</i>;
>> +     * otherwise, it is equal to the character at index <i>k-n</i> in the
>> +     * argument {@code sb}.
>> +     * <p>
>> +     *
>> +     * @param   sb   the {@code StringBuilder} to append.
>> +     * @return  a reference to this object.
>> +     */
>> +    public synchronized StringBuffer append(StringBuilder sb) {
>> +        toStringCache = null;
>> +        super.append(sb);
>> +        return this;
>> +    }
>> +
>>      /**
>>       * Appends the specified {@code StringBuffer} to this sequence.
>>       * <p>
>> diff --git a/src/java.base/share/classes/java/lang/StringBuilder.java
>> b/src/java.base/share/classes/java/lang/StringBuilder.java
>> index 40da2083c2..5ddd4fb5f9 100644
>> --- a/src/java.base/share/classes/java/lang/StringBuilder.java
>> +++ b/src/java.base/share/classes/java/lang/StringBuilder.java
>> @@ -199,6 +199,30 @@ public final class StringBuilder
>>          return this;
>>      }
>>
>> +    /**
>> +     * Appends the specified {@code StringBuilder} to this sequence.
>> +     * <p>
>> +     * The characters of the {@code StringBuilder} argument are appended,
>> +     * in order, to this sequence, increasing the
>> +     * length of this sequence by the length of the argument.
>> +     * If {@code sb} is {@code null}, then the four characters
>> +     * {@code "null"} are appended to this sequence.
>> +     * <p>
>> +     * Let <i>n</i> be the length of this character sequence just prior
>> to
>> +     * execution of the {@code append} method. Then the character at
>> index
>> +     * <i>k</i> in the new character sequence is equal to the character
>> at
>> +     * index <i>k</i> in the old character sequence, if <i>k</i> is less
>> than
>> +     * <i>n</i>; otherwise, it is equal to the character at index
>> <i>k-n</i>
>> +     * in the argument {@code sb}.
>> +     *
>> +     * @param   sb   the {@code StringBuilder} to append.
>> +     * @return  a reference to this object.
>> +     */
>> +    public StringBuilder append(StringBuilder sb) {
>> +        super.append(sb);
>> +        return this;
>> +    }
>> +
>>      @Override
>>      public StringBuilder append(CharSequence s) {
>>          super.append(s);
>
>