On Thu, 10 Nov 2022 17:42:04 GMT, Jim Laskey <jlas...@openjdk.org> wrote:
>> Enhance the Java programming language with string templates, which are >> similar to string literals but contain embedded expressions. A string >> template is interpreted at run time by replacing each expression with the >> result of evaluating that expression, possibly after further validation and >> transformation. This is a [preview language feature and >> API](http://openjdk.java.net/jeps/12). > > Jim Laskey has updated the pull request incrementally with one additional > commit since the last revision: > > Requested changes #5 src/java.base/share/classes/java/lang/template/Carriers.java line 415: > 413: */ > 414: @Stable > 415: private final Object[] objects; Looking at all this, I'm skeptical that carriers are worth the complexity for the performance gain they give. AFAICS the fast paths for `FMT` and `STR` avoid boxing values into a StringTemplate instance altogether. So carriers only seem to help cases where processing goes through the default `process` method on a user-defined processor? AFAIK `@Stable` will not do anything here. It only helps constant folding from a constant root object and in general StringTemplate instances are not constant. (and, AFAIK there are also JIT caveats with storing everything in arrays like this). I suggest maybe keeping things simple in this PR, and having a `StringTemplateImpl` with just a `List<Object>` for the values. Public support for the linkage-based fast path can be used to avoid the boxing for user defined processors in the future as well, and that seems like a much better way to get performance to me. If carriers are added to improve performance, I'd personally like to see that in a separate PR that's only focused on that, with more benchmarks/bench marking results included as well. ------------- PR: https://git.openjdk.org/jdk/pull/10889
