On Wed, 2 Nov 2022 19:44:00 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: > > Internalize TemplateSupport src/java.base/share/classes/java/lang/invoke/StringConcatFactory.java line 1103: > 1101: } > 1102: > 1103: MethodHandle mh = MethodHandles.dropArguments(newString(), 2, > ttypes); The code here us pretty dense. I suggest adding comments that show the type of `mh` as far as it is known. I think it makes it a much easier to keep track of what all the argument indexes mean. e.g. Suggestion: // (byte[],long,ttypes...) -> String MethodHandle mh = MethodHandles.dropArguments(newString(), 2, ttypes); src/java.base/share/classes/java/lang/invoke/StringConcatFactory.java line 1118: > 1116: MethodHandle prepender = prepender(lastFragment.isEmpty() ? > null : fragment, ttype); > 1117: initialLengthCoder = > JLA.stringConcatMix(initialLengthCoder, fragment); > 1118: mh = MethodHandles.filterArgumentsWithCombiner(mh, 1, > prepender,1, 0, 2 + pos); Suggestion: Class<?> ttype = ttypes[pos]; // (long,byte[],ttype) -> String MethodHandle prepender = prepender(lastFragment.isEmpty() ? null : fragment, ttype); initialLengthCoder = JLA.stringConcatMix(initialLengthCoder, fragment); // (byte[],long,ttypes...) -> String (unchanged) mh = MethodHandles.filterArgumentsWithCombiner(mh, 1, prepender,1, 0, 2 + pos); src/java.base/share/classes/java/lang/invoke/StringConcatFactory.java line 1125: > 1123: MethodHandle newArrayCombinator = lastFragment.isEmpty() ? > newArray() : > 1124: newArrayWithSuffix(lastFragment); > 1125: mh = MethodHandles.foldArgumentsWithCombiner(mh, 0, > newArrayCombinator, Suggestion: // (long,ttypes...) -> String mh = MethodHandles.foldArgumentsWithCombiner(mh, 0, newArrayCombinator, src/java.base/share/classes/java/lang/invoke/StringConcatFactory.java line 1143: > 1141: 0, // old-index > 1142: 1 + pos // selected argument > 1143: ); Suggestion: // (long,ttype) -> long MethodHandle mix = mixer(ttypes[pos]); boolean lastPType = pos == ttypes.length - 1; if (lastPType) { // (ttype) -> long mix = MethodHandles.insertArguments(mix, 0, initialLengthCoder); // (ttypes...) -> String mh = MethodHandles.foldArgumentsWithCombiner(mh, 0, mix, 1 + pos // selected argument ); } else { // (long,ttypes...) -> String mh = MethodHandles.filterArgumentsWithCombiner(mh, 0, mix, 0, // old-index 1 + pos // selected argument ); ------------- PR: https://git.openjdk.org/jdk/pull/10889
