FWIW, the few times I "needed" a repeat operation it's always been with a char, not a string. I think a common use case for this to create some layout in the printed string, such as adding a separator (e.g. "*********", "---------", etc) or adding white space padding (could also be something like "..........") to align output - both are just chars.
Sent from my phone On Aug 22, 2012 5:47 AM, "Alan Bateman" <alan.bate...@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/~jgish/6984084-jdk8-StringRepeat/>< >> http://cr.openjdk.java.net/%**7Ejgish/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'm less sure about StringBuilder.append(int,**CharSequence) as > sb.append(5,cs) is not much less than "for (int i=0; i<5; i++) > sb.append(cs);". I also wonder whether it may be more common to want to > appear a number of chars, sb.append(5, '-') for example. > > Anyway, on the javadoc then AbstractStringBuilder.append suggests special > hanging for n==1 but I think that can be dropped the javadoc. > > On the implementation then it would be good to make the style consistent > with the existing code (4 spaces for indent, etc.). Otherwise it seems okay. > > I assume the update to test/Makefile is just for your own local usage and > that you aren't planning to include this (the jdk_lang target already runs > the tests in test/java/lang/**). > > In Repeat.java (same thing in AppendIntCharSequence.java) then I think the > -1 test can be simplified to: > > try { > "c".repeat(-1); > throw new RuntimeException(...); > } catch (IllegalArgumenetException expected) { } > > We use GPL on the tests so you need to check AppendIntCharSequence.java. > > On test coverage then it looks like StringBuffer is missed. Also the > assertion that appending null will append "null". > > -Alan. > > >
