vim-patch:7129f2a: runtime(java): Improve the matching of lambda expressions (vim/vim#14880)

- Distinguish some formal parameters.
- Support multi-line definitions.

https://github.com/vim/vim/commit/7129f2ad2fd9de3e3812a569ba3ad6bf162fd238

Co-authored-by: Aliaksei Budavei <32549825+zzzyxwvut@users.noreply.github.com>

1 files changed, 19 insertions, 3 deletions

diff --git a/runtime/syntax/java.vim b/runtime/syntax/java.vim
index 9867b147c2..5ba724d24e 100644
--- a/runtime/syntax/java.vim
+++ b/runtime/syntax/java.vim
@@ -3,7 +3,7 @@
 " Maintainer:		Aliaksei Budavei <0x000c70 AT gmail DOT com>
 " Former Maintainer:	Claudio Fleiner <claudio@fleiner.com>
 " Repository:		https://github.com/zzzyxwvut/java-vim.git
-" Last Change:		2024 May 10
+" Last Change:		2024 May 30
 
 " Please check :help java.vim for comments on some of the options available.
 
@@ -348,7 +348,6 @@ if exists("java_highlight_functions")
     exec 'syn region javaFuncDef start=/' . s:ff.Engine('\%#=2', '') . '^\s\+\%(\%(@\%(\K\k*\.\)*\K\k*\>\)\s\+\)*\%(p\%(ublic\|rotected\|rivate\)\s\+\)\=\%(\%(abstract\|default\)\s\+\|\%(\%(final\|\%(native\|strictfp\)\|s\%(tatic\|ynchronized\)\)\s\+\)*\)\=\%(<.*[[:space:]-]\@' . s:ff.Peek('1', '') . '<!>\s\+\)\=\%(void\|\%(b\%(oolean\|yte\)\|char\|short\|int\|long\|float\|double\|\%(\<\K\k*\>\.\)*\<' . s:ff.UpperCase('[$_[:upper:]]', '[^a-z0-9]') . '\k*\>\%(<[^(){}]*[[:space:]-]\@' . s:ff.Peek('1', '') . '<!>\)\=\)\%(\[\]\)*\)\s\+\<' . s:ff.LowerCase('[$_[:lower:]]', '[^A-Z0-9]') . '\k*\>\s*(/ end=/)/ skip=/\/\*.\{-}\*\/\|\/\/.*$/ contains=@javaFuncParams'
   endif
 
-  exec 'syn match javaLambdaDef "\<\K\k*\>\%(\<default\>\)\@' . s:ff.Peek('7', '') . '<!\s*->"'
   syn match javaBraces "[{}]"
 endif
 
@@ -421,9 +420,26 @@ syn match   javaParenError	 "\]"
 
 hi def link javaParenError	javaError
 
+" Lambda expressions (JLS-17, §15.27).
 if exists("java_highlight_functions")
   " Make ()-matching definitions after the parenthesis error catcher.
-  exec 'syn match javaLambdaDef "\k\@' . s:ff.Peek('4', '') . '<!(\%(\k\|[[:space:]<>?\[\]@,.]\)*)\s*->"'
+  "
+  " Match: ([@A [@B ...] final] var a[, var b, ...]) ->
+  "	| ([@A [@B ...] final] T[<α>][[][]] a[, T b, ...]) ->
+  " There is no recognition of expressions interspersed with comments
+  " or of expressions whose parameterised parameter types are written
+  " across multiple lines.
+  exec 'syn match javaLambdaDef "\k\@' . s:ff.Peek('4', '') . '<!([[:space:]\n]*\%(\%(@\%(\K\k*\.\)*\K\k*\>\%((\_.\{-1,})\)\{-,1}[[:space:]\n]\+\)*\%(final[[:space:]\n]\+\)\=\%(\<\K\k*\>\.\)*\<\K\k*\>\%(<[^(){}]*[[:space:]-]\@' . s:ff.Peek('1', '') . '<!>\)\=\%(\%(\%(\[\]\)\+\|\.\.\.\)\)\=[[:space:]\n]\+\<\K\k*\>\%(\[\]\)*\%(,[[:space:]\n]*\)\=\)\+)[[:space:]\n]*->" contains=javaAnnotation,javaParamModifier,javaLambdaVarType,javaType,@javaClasses,javaVarArg'
+  " Match: () ->
+  "	| (a[, b, ...]) ->
+  exec 'syn match javaLambdaDef "\k\@' . s:ff.Peek('4', '') . '<!([[:space:]\n]*\%(\<\K\k*\>\%(,[[:space:]\n]*\)\=\)*)[[:space:]\n]*->"'
+  " Match: a ->
+  exec 'syn match javaLambdaDef "\<\K\k*\>\%(\<default\>\)\@' . s:ff.Peek('7', '') . '<![[:space:]\n]*->"'
+
+  syn keyword javaParamModifier contained final
+  hi def link javaParamModifier javaConceptKind
+  syn keyword javaLambdaVarType contained var
+  hi def link javaLambdaVarType javaOperator
 endif
 
 " The @javaTop cluster comprises non-contained Java syntax groups.