Please Review: 6984084 (str) n times repetition of character constructor for java.lang.String

[Stephen Colebourne]

On 22 August 2012 10:46, Alan Bateman <Alan.Bateman at oracle.com> wrote:
> On 21/08/2012 21:45, Jim Gish wrote:
>> Please review http://cr.openjdk.java.net/~jgish/6984084-jdk8-StringRepeat/
>> <http://cr.openjdk.java.net/%7Ejgish/6984084-jdk8-StringRepeat/>
>>
>> This started in lambda, making changes to both StringJoiner and String.
>> However, the dependence of String.repeat() on StringJoiner has been removed
>> and the resulting non-lambda classes moved here for review.  There will be a
>> separate change and review for the StringJoiner changes in lamda-dev.
>
> On the surface then String s = "foo".repeat(5); seems nice. I just wonder
> whether we can get any data on usage of similar methods in commonly used
> libraries. Some languages such as Python have a built-ins for this, and I
> think C# has a ctor, just not clear (to me anyway) how often the latter or
> equivalent it used. Folks here might be able to jump in to indicate how
> often they've needed to do this and whether the common-case is a repeated
> char rather than String (or CharSequence). Folks here might also have ideas
> on getting some usage data in other libraries or languages.

I don't think this is used that often and of marginal value in the
JDK. If added, perhaps it should go in the buffer/builder only.

By comparison, padding is a much useful missing JDK feature:
 https://github.com/apache/commons-lang/blob/trunk/src/main/java/org/apache/commons/lang3/StringUtils.java#L4451

Stephen