Introduce a new API variable "g:java_syntax_previews" whose
value must be a list of syntax preview feature numbers.
Enumerate the currently supported numbers in a table at the
end of the documentation entry for "ft-java-syntax".
Also, disable the recognition of String Templates. Despite
the withdrawal of this preview feature in its proposed form
from the upcoming JDK 23 release and the fact that the JDK
22 release is coming to EOL this September, an earlier
iteration of this preview feature was included in JDK 21
(LTS) whose EOL is projected to fall due in late 2028 and,
therefore, retain the current implementation.
Define "g:java_syntax_previews" and include number 430 in
its list to enable the recognition of String Templates:
------------------------------------------------------------
let g:java_syntax_previews = [430]
------------------------------------------------------------
References:
https://openjdk.org/jeps/430 (Preview)
https://openjdk.org/jeps/459 (Second Preview)
https://openjdk.org/jeps/465 (Third Preview)
https://mail.openjdk.org/pipermail/amber-spec-experts/2024-April/004106.htmlcloses: #15579
Signed-off-by: Aliaksei Budavei <0x000c70@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
As this is encouraged in the referenced JEPs, "to visually
distinguish a string template from a string literal, and
a text block template from a text block", the default
colours for java\%[Debug]StrTempl are made distinct from
java\%[Debug]String.
According to §3.2 Lexical Translations (JLS, c. 1996 or any
more recent version), line terminators, white space, and
comments are discarded before tokens are accepted. Since
a template expression comprises a template processor, a dot,
and a template, it may be visually appealing to break up
its head across a few lines whenever its tail already spans
multiple lines. Curiously, no allowance for it is made in
the distributed tests for OpenJDK 21; the proposed regexp
patterns take in consideration a line terminator and white
space after a dot.
References:
https://openjdk.org/jeps/430 (Preview)
https://openjdk.org/jeps/459 (Second Preview)
https://openjdk.org/jeps/465
Signed-off-by: Aliaksei Budavei <0x000c70@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
Also, accept as valid the space escape sequence `\s`.
Also, consistently use the claimed `javaDebug` prefix for
syntax group definitions kept under `g:java_highlight_debug`.
Since `javaStringError` is commented out for its generality,
let's comment out `javaDebugStringError`, its copy, as well.
References:
https://openjdk.org/jeps/378https://docs.oracle.com/javase/specs/jls/se17/html/jls-3.html#jls-3.10.7Closes#10910.
Signed-off-by: Aliaksei Budavei <0x000c70@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
