runtime(java): Improve the matching of lambda expressions (#14880)

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

Signed-off-by: Aliaksei Budavei <0x000c70@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

9 files changed, 263 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.
diff --git a/runtime/syntax/testdir/dumps/java_lambda_expressions_00.dump b/runtime/syntax/testdir/dumps/java_lambda_expressions_00.dump
new file mode 100644
index 0000000000..eb136e6927
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/java_lambda_expressions_00.dump
@@ -0,0 +1,20 @@
+>/+0#0000e05#ffffff0@1| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |l|e|t| |g|:|j|a|v|a|_|h|i|g|h|l|i|g|h|t|_|f|u|n|c|t|i|o|n|s| |=| |'|s|t|y|l|e|'| +0#0000000&@16
+@75
+@75
+|i+0#e000e06&|m|p|o|r|t| +0#0000000&|j|a|v|a|.|l|a|n|g|.|a|n@1|o|t|a|t|i|o|n|.|E|l|e|m|e|n|t|T|y|p|e|;| @34
+|i+0#e000e06&|m|p|o|r|t| +0#0000000&|j|a|v|a|.|u|t|i|l|.|f|u|n|c|t|i|o|n|.|B|i|n|a|r|y|O|p|e|r|a|t|o|r|;| @33
+|i+0#e000e06&|m|p|o|r|t| +0#0000000&|j|a|v|a|.|u|t|i|l|.|f|u|n|c|t|i|o|n|.|F|u|n|c|t|i|o|n|;| @39
+@75
+|c+0#00e0003&|l|a|s@1| +0#0000000&|L|a|m|b|d|a|E|x|p|r|e|s@1|i|o|n|s|T|e|s|t|s| @46
+|{+0#00e0e07&| +0#0000000&@73
+| +0#00e0e07&@3|<|I|1|,| |C|1|,| |C|2|,| |T|1|,| |T|2|,| |T|3|,| |Z|1|,| |Z|2|,| |Z|3|,| |S|1|,| |S|2|,| |S|3|>| |v+0#00e0003&|o|i|d| +0#00e0e07&|t|e|s|t|(|)| +0#0000000&@10
+@4|{+0#00e0e07&| +0#0000000&@2|/+0#0000e05&@1| |S|c|h|ö|n|f|i|n|k|e|l|'|s| |f|u|n|c|t|i|o|n|s|.| +0#0000000&@39
+@8|I|<|I|1|>| |i| |=| |x+0#00e0e07&| |-|>| +0#0000000&|x|;| @49
+@8|C|<|C|1|,| |C|2|>| |c| |=| |x+0#00e0e07&| |-|>| +0#0000000&|y+0#00e0e07&| |-|>| +0#0000000&|x|;| @40
+@8|T|<|T|1|,| |T|2|,| |T|3|>| |t| |=| |f+0#00e0e07&| |-|>| +0#0000000&|y+0#00e0e07&| |-|>| +0#0000000&|x+0#00e0e07&| |-|>| +0#0000000&|f|.|a|p@1|l|y|(|x|)|.|a|p@1|l|y|(|y|)|;| @13
+@8|Z|<|Z|1|,| |Z|2|,| |Z|3|>| |z| |=| |f+0#00e0e07&| |-|>| +0#0000000&|g+0#00e0e07&| |-|>| +0#0000000&|x+0#00e0e07&| |-|>| +0#0000000&|f|.|a|p@1|l|y|(|g|.|a|p@1|l|y|(|x|)@1|;| @13
+@8|S|<|S|1|,| |S|2|,| |S|3|>| |s| |=| |f+0#00e0e07&| |-|>| +0#0000000&|g+0#00e0e07&| |-|>| +0#0000000&|x+0#00e0e07&| |-|>| +0#0000000&|f|.|a|p@1|l|y|(|x|)| @23
+@24|.|a|p@1|l|y|(|g|.|a|p@1|l|y|(|x|)@1|;| @31
+@75
+@8|I|<|I|1|>| |i|0|1| |=| |(+0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|)| |-|>| +0#0000000&|x|;| @41
+@57|1|,|1| @10|T|o|p| 
diff --git a/runtime/syntax/testdir/dumps/java_lambda_expressions_01.dump b/runtime/syntax/testdir/dumps/java_lambda_expressions_01.dump
new file mode 100644
index 0000000000..53bb657d05
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/java_lambda_expressions_01.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@7|T|<|T|1|,| |T|2|,| |T|3|>| |t| |=| |f+0#00e0e07&| |-|>| +0#0000000&|y+0#00e0e07&| |-|>| +0#0000000&|x+0#00e0e07&| |-|>| +0#0000000&|f|.|a|p@1|l|y|(|x|)|.|a|p@1|l|y|(|y|)|;| @13
+@8|Z|<|Z|1|,| |Z|2|,| |Z|3|>| |z| |=| |f+0#00e0e07&| |-|>| +0#0000000&|g+0#00e0e07&| |-|>| +0#0000000&|x+0#00e0e07&| |-|>| +0#0000000&|f|.|a|p@1|l|y|(|g|.|a|p@1|l|y|(|x|)@1|;| @13
+@8|S|<|S|1|,| |S|2|,| |S|3|>| |s| |=| |f+0#00e0e07&| |-|>| +0#0000000&|g+0#00e0e07&| |-|>| +0#0000000&|x+0#00e0e07&| |-|>| +0#0000000&|f|.|a|p@1|l|y|(|x|)| @23
+@24|.|a|p@1|l|y|(|g|.|a|p@1|l|y|(|x|)@1|;| @31
+@75
+@8>I|<|I|1|>| |i|0|1| |=| |(+0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|)| |-|>| +0#0000000&|x|;| @41
+@8|I|<|I|1|>| |i|0|2| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|)| |-|>| +0#0000000&|x|;| @31
+@8|I|<|I|1|>| |i|0|3| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|)| |-|>| +0#0000000&|x|;| @21
+@8|I|<|I|1|>| |i|0|4| |=| |(+0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|)| |-|>| +0#0000000&|x|;| @35
+@8|I|<|I|1|>| |i|0|5| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|)| |-|>| +0#0000000&|x|;| @25
+@8|I|<|I|1|>| |i|0|6| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|)| |-|>| +0#0000000&|x|;| @15
+@8|I|<|I|1|>| |i|0|7| |=| |(+0#00e0e07&|I|1| |x|)| |-|>| +0#0000000&|x|;| @42
+@8|I|<|I|1|>| |i|0|8| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|I|1| |x|)| |-|>| +0#0000000&|x|;| @32
+@8|I|<|I|1|>| |i|0|9| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|I|1| |x|)| |-|>| +0#0000000&|x|;| @22
+@8|I|<|I|1|>| |i|1|0| |=| |(+0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|I|1| |x|)| |-|>| +0#0000000&|x|;| @36
+@8|I|<|I|1|>| |i|1@1| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|I|1| |x|)| |-|>| +0#0000000&|x|;| @26
+@8|I|<|I|1|>| |i|1|2| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|I|1| |x|)| |-|>| +0#0000000&|x|;| @16
+@75
+@8|I|<|I|1|[|]|>| |i@1|0|1| |=| |(+0#00e0e07&|I|1|.@2| |x|)| |-|>| +0#0000000&|x|;| @36
+@57|1|9|,|3|-|9| @7|1|5|%| 
diff --git a/runtime/syntax/testdir/dumps/java_lambda_expressions_02.dump b/runtime/syntax/testdir/dumps/java_lambda_expressions_02.dump
new file mode 100644
index 0000000000..6fe6bb2b53
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/java_lambda_expressions_02.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@7|I|<|I|1|[|]|>| |i@1|0|1| |=| |(+0#00e0e07&|I|1|.@2| |x|)| |-|>| +0#0000000&|x|;| @36
+@8|I|<|I|1|[|]|>| |i@1|0|2| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|I|1|.@2| |x|)| |-|>| +0#0000000&|x|;| @26
+@8|I|<|I|1|[|]|>| |i@1|0|3| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|I|1|.@2| |x|)| |-|>| +0#0000000&|x|;| @16
+@8|I|<|I|1|[|]|>| |i@1|0|4| |=| |(+0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|I|1|.@2| |x|)| |-|>| +0#0000000&|x|;| @30
+@8|I|<|I|1|[|]|>| |i@1|0|5| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|I|1|.@2| |x|)| |-|>| +0#0000000&|x|;| @20
+@8>I|<|I|1|[|]|>| |i@1|0|6| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|I|1|.@2| |x|)| |-|>| +0#0000000&|x|;| @10
+@75
+@8|B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t|0|1| |=| |(+0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|,| |v+0#af5f00255&|a|r| +0#00e0e07&|y|)| |-|>| +0#0000000&|x|;| @13
+@8|B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t|0|2| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|,| +0#0000000&@16
+| +0#00e0e07&@19|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|y|)| |-|>| +0#0000000&|x|;| @32
+@8|B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t|0|3| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|v+0#af5f00255&|a|r| +0#0000000&@9
+| +0#00e0e07&@19|x|,| |@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|y|)| |-|>| +0#0000000&|x|;| @19
+@8|B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t|0|4| |=| |(+0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|,| +0#0000000&@20
+| +0#00e0e07&@19|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|y|)| |-|>| +0#0000000&|x|;| @36
+@8|B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t|0|5| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#0000000&@17
+| +0#00e0e07&@19|v+0#af5f00255&|a|r| +0#00e0e07&|x|,| |@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|y|)| |-|>| +0#0000000&|x|;| @19
+@8|B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t|0|6| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#0000000&@23
+| +0#00e0e07&@19|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|,| +0#0000000&@32
+| +0#00e0e07&@19|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#0000000&@45
+@57|3|7|,|3|-|9| @7|3|6|%| 
diff --git a/runtime/syntax/testdir/dumps/java_lambda_expressions_03.dump b/runtime/syntax/testdir/dumps/java_lambda_expressions_03.dump
new file mode 100644
index 0000000000..e98b3b1e9c
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/java_lambda_expressions_03.dump
@@ -0,0 +1,20 @@
+| +0#00e0e07#ffffff0@19|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#0000000&@45
+| +0#00e0e07&@19|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|y|)| |-|>| +0#0000000&|x|;| @26
+@8|B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t|0|7| |=| |(+0#00e0e07&|I|1| |x|,| |I|1| |y|)| |-|>| +0#0000000&|x|;| @15
+@8|B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t|0|8| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|I|1| |x|,| +0#0000000&@17
+| +0#00e0e07&@19|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|I|1| |y|)| |-|>| +0#0000000&|x|;| @33
+@8>B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t|0|9| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|I|1| +0#0000000&@10
+| +0#00e0e07&@19|x|,| |@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|I|1| |y|)| |-|>| +0#0000000&|x|;| @20
+@8|B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t|1|0| |=| |(+0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|I|1| |x|,| +0#0000000&@21
+| +0#00e0e07&@19|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|I|1| |y|)| |-|>| +0#0000000&|x|;| @37
+@8|B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t|1@1| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#0000000&@17
+| +0#00e0e07&@19|I|1| |x|,| |@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|I|1| |y|)| |-|>| +0#0000000&|x|;| @21
+@8|B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t|1|2| |=| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#0000000&@23
+| +0#00e0e07&@19|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|I|1| |x|,| +0#0000000&@33
+| +0#00e0e07&@19|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#0000000&@45
+| +0#00e0e07&@19|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|f+0#4040ff13&|i|n|a|l| +0#00e0e07&|I|1| |y|)| |-|>| +0#0000000&|x|;| @27
+@75
+@8|R|u|n@1|a|b|l|e| |n|o|O|p| |=| |(+0#00e0e07&|)| |-|>| +0#0000000&|{+0#00e0e07&|}|;+0#0000000&| @41
+@8|B|i|n|a|r|y|O|p|e|r|a|t|o|r|<|I|1|>| |l|e|f|t|C|o|n|s|t| |=| |(+0#00e0e07&|x|,| |y|)| |-|>| +0#0000000&|x|;| @23
+@8|I|<|I|1|>| |i|d|1| |=| |(+0#00e0e07&|x|)| |-|>| +0#0000000&|(|x|)|;| @43
+@57|5@1|,|3|-|9| @7|5|7|%| 
diff --git a/runtime/syntax/testdir/dumps/java_lambda_expressions_04.dump b/runtime/syntax/testdir/dumps/java_lambda_expressions_04.dump
new file mode 100644
index 0000000000..470f9463a9
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/java_lambda_expressions_04.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@7|I|<|I|1|>| |i|d|1| |=| |(+0#00e0e07&|x|)| |-|>| +0#0000000&|(|x|)|;| @43
+@8|@+0#e000e06&|S|u|p@1|r|e|s@1|W|a|r|n|i|n|g|s|(+0#0000000&|"+0#e000002&|u|n|c|h|e|c|k|e|d|"|)+0#0000000&| |I|<|I|1|>| |i|d|2| |=| @24
+@16|(@1|I|<|I|<|I|1|>@1|)| |(|I|<|?|>|)| |(|F|u|n|c|t|i|o|n|<|I|1|,| @26
+@20|I|1|>| |x|)| |-|>| |x|)|.|a|p@1|l|y|(|s+0#af5f00255&|w|i|t|c|h| +0#0000000&|(|0+0#e000002&|)+0#0000000&| |{+0#00e0e07&| +0#0000000&@23
+@16|c+0#af5f00255&|a|s|e| +0#0000000&|(@1|i+0#00e0003&|n|t|)+0#0000000&| |(|b+0#00e0003&|y|t|e|)+0#0000000&| |1+0#e000002&|)+0#0000000&| |-|>| |(+0#00e0e07&|I|1| |x|)| |-|>| +0#0000000&|x|;| @21
+@16>d+0#af5f00255&|e|f|a|u|l|t| +0#0000000&|-|>| |(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|I|1| |x|)| |-|>| +0#0000000&|x|;| |}+0#00e0e07&|)+0#0000000&|;| @21
+@8|C|<|C|1|,| |C|2|>| |c|o|n|s|t|1| |=| |(+0#00e0e07&|x|)| |-|>| +0#0000000&|(+0#00e0e07&|y|)| |-|>| +0#0000000&|(|x|)|;| @29
+@8|C|<|C|1|,| |C|2|>| |c|o|n|s|t|2| |=| |s+0#af5f00255&|w|i|t|c|h|(+0#0000000&|s+0#af5f00255&|w|i|t|c|h| +0#0000000&|(|"+0#e000002&@1|)+0#0000000&| |{+0#00e0e07&| +0#0000000&@27
+@24|c+0#af5f00255&|a|s|e| +0#0000000&|"+0#e000002&|-|>|"|-+0#0000000&|>|"+0#e000002&|(|s|)|-|>|(|s|)|"|;+0#0000000&| @28
+@24|d+0#af5f00255&|e|f|a|u|l|t|-+0#0000000&|>|"+0#e000002&|d|e|f|a|u|l|t|"|;+0#0000000&| |}+0#00e0e07&|)+0#0000000&| |{+0#00e0e07&| +0#0000000&@26
+@12|c+0#af5f00255&|a|s|e| +0#0000000&|(|"+0#e000002&|-|>|"|)+0#0000000&|-|>|(+0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|)|-|>|(|v+0#af5f00255&|a|r| +0#00e0e07&|y|)|-|>|(+0#0000000&|x|)|;| @27
+@12|d+0#af5f00255&|e|f|a|u|l|t|-+0#0000000&|>|(+0#00e0e07&|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|x|)|-|>|(|@+0#e000e06&|T|a|g@1|a|b|l|e| +0#00e0e07&|v+0#af5f00255&|a|r| +0#00e0e07&|y|)| +0#0000000&@17
+| +0#00e0e07&@15|-|>|(+0#0000000&|x|)|;| @52
+@8|}+0#00e0e07&|;+0#0000000&| @64
+@4|}+0#00e0e07&| +0#0000000&@69
+@75
+@4|@+0#e000e06&|j|a|v|a|.|l|a|n|g|.|a|n@1|o|t|a|t|i|o|n|.|T|a|r|g|e|t|(+0#0000000&|E|l|e|m|e|n|t|T|y|p|e|.|P|A|R|A|M|E|T|E|R|)| @19
+@4|@+0#e000e06&|j|a|v|a|.|l|a|n|g|.|a|n@1|o|t|a|t|i|o|n|.|R|e|p|e|a|t|a|b|l|e|(+0#0000000&|T|a|g@1|a|b|l|e|s|.|c+0#00e0003&|l|a|s@1|)+0#0000000&| @21
+@4|@+0#00e0003&|i|n|t|e|r|f|a|c|e| +0#0000000&|T|a|g@1|a|b|l|e| |{+0#00e0e07&| +0#0000000&|S|t|r|i|n|g|[|]| |v|a|l|u|e|(|)| |d+0#4040ff13&|e|f|a|u|l|t| +0#0000000&|"+0#e000002&@1|;+0#0000000&| |}+0#00e0e07&| +0#0000000&@18
+@57|7|3|,|5|-|1|7| @6|7|8|%| 
diff --git a/runtime/syntax/testdir/dumps/java_lambda_expressions_05.dump b/runtime/syntax/testdir/dumps/java_lambda_expressions_05.dump
new file mode 100644
index 0000000000..fe5415d4fb
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/java_lambda_expressions_05.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@3|@+0#00e0003&|i|n|t|e|r|f|a|c|e| +0#0000000&|T|a|g@1|a|b|l|e| |{+0#00e0e07&| +0#0000000&|S|t|r|i|n|g|[|]| |v|a|l|u|e|(|)| |d+0#4040ff13&|e|f|a|u|l|t| +0#0000000&|"+0#e000002&@1|;+0#0000000&| |}+0#00e0e07&| +0#0000000&@18
+@75
+@4|@+0#e000e06&|j|a|v|a|.|l|a|n|g|.|a|n@1|o|t|a|t|i|o|n|.|T|a|r|g|e|t|(+0#0000000&|E|l|e|m|e|n|t|T|y|p|e|.|P|A|R|A|M|E|T|E|R|)| @19
+@4|@+0#00e0003&|i|n|t|e|r|f|a|c|e| +0#0000000&|T|a|g@1|a|b|l|e|s| |{+0#00e0e07&| +0#0000000&|T|a|g@1|a|b|l|e|[|]| |v|a|l|u|e|(|)|;| |}+0#00e0e07&| +0#0000000&@26
+@75
+@4>i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|<|A|1|>| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|F|u|n|c|t|i|o|n|<|A|1|,| |A|1|>| |{+0#00e0e07&| +0#0000000&|}+0#00e0e07&| +0#0000000&@26
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|C|<|A|1|,| |A|2|>| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|F|u|n|c|t|i|o|n|<|A|1|,| |F|u|n|c|t|i|o|n|<|A|2|,| |A|1|>@1| |{+0#00e0e07&| +0#0000000&|}+0#00e0e07&| +0#0000000&@8
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|T|<|A|1|,| |A|2|,| |A|3|>| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&@39
+@16|F|u|n|c|t|i|o|n|<|F|u|n|c|t|i|o|n|<|A|1|,| |F|u|n|c|t|i|o|n|<|A|2|,| |A|3|>@1|,| @18
+@20|F|u|n|c|t|i|o|n|<|A|2|,| @42
+@20|F|u|n|c|t|i|o|n|<|A|1|,| |A|3|>@2| |{+0#00e0e07&| +0#0000000&|}+0#00e0e07&| +0#0000000&@32
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|Z|<|A|1|,| |A|2|,| |A|3|>| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|F|u|n|c|t|i|o|n|<|F|u|n|c|t|i|o|n|<|A|2|,| |A|3|>|,| @12
+@20|F|u|n|c|t|i|o|n|<|F|u|n|c|t|i|o|n|<|A|1|,| |A|2|>|,| @28
+@20|F|u|n|c|t|i|o|n|<|A|1|,| |A|3|>@2| |{+0#00e0e07&| +0#0000000&|}+0#00e0e07&| +0#0000000&@32
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|S|<|A|1|,| |A|2|,| |A|3|>| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&@39
+@16|F|u|n|c|t|i|o|n|<|F|u|n|c|t|i|o|n|<|A|1|,| |F|u|n|c|t|i|o|n|<|A|2|,| |A|3|>@1|,| @18
+@20|F|u|n|c|t|i|o|n|<|F|u|n|c|t|i|o|n|<|A|1|,| |A|2|>|,| @28
+@20|F|u|n|c|t|i|o|n|<|A|1|,| |A|3|>@2| |{+0#00e0e07&| +0#0000000&|}+0#00e0e07&| +0#0000000&@32
+|}+0#00e0e07&| +0#0000000&@73
+@57|9|1|,|2|-|5| @7|B|o|t| 
diff --git a/runtime/syntax/testdir/dumps/java_lambda_expressions_99.dump b/runtime/syntax/testdir/dumps/java_lambda_expressions_99.dump
new file mode 100644
index 0000000000..9bc45ebc9d
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/java_lambda_expressions_99.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@3|@+0#00e0003&|i|n|t|e|r|f|a|c|e| +0#0000000&|T|a|g@1|a|b|l|e| |{+0#00e0e07&| +0#0000000&|S|t|r|i|n|g|[|]| |v|a|l|u|e|(|)| |d+0#4040ff13&|e|f|a|u|l|t| +0#0000000&|"+0#e000002&@1|;+0#0000000&| |}+0#00e0e07&| +0#0000000&@18
+@75
+@4|@+0#e000e06&|j|a|v|a|.|l|a|n|g|.|a|n@1|o|t|a|t|i|o|n|.|T|a|r|g|e|t|(+0#0000000&|E|l|e|m|e|n|t|T|y|p|e|.|P|A|R|A|M|E|T|E|R|)| @19
+@4|@+0#00e0003&|i|n|t|e|r|f|a|c|e| +0#0000000&|T|a|g@1|a|b|l|e|s| |{+0#00e0e07&| +0#0000000&|T|a|g@1|a|b|l|e|[|]| |v|a|l|u|e|(|)|;| |}+0#00e0e07&| +0#0000000&@26
+@75
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|I|<|A|1|>| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|F|u|n|c|t|i|o|n|<|A|1|,| |A|1|>| |{+0#00e0e07&| +0#0000000&|}+0#00e0e07&| +0#0000000&@26
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|C|<|A|1|,| |A|2|>| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|F|u|n|c|t|i|o|n|<|A|1|,| |F|u|n|c|t|i|o|n|<|A|2|,| |A|1|>@1| |{+0#00e0e07&| +0#0000000&|}+0#00e0e07&| +0#0000000&@8
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|T|<|A|1|,| |A|2|,| |A|3|>| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&@39
+@16|F|u|n|c|t|i|o|n|<|F|u|n|c|t|i|o|n|<|A|1|,| |F|u|n|c|t|i|o|n|<|A|2|,| |A|3|>@1|,| @18
+@20|F|u|n|c|t|i|o|n|<|A|2|,| @42
+@20|F|u|n|c|t|i|o|n|<|A|1|,| |A|3|>@2| |{+0#00e0e07&| +0#0000000&|}+0#00e0e07&| +0#0000000&@32
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|Z|<|A|1|,| |A|2|,| |A|3|>| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&|F|u|n|c|t|i|o|n|<|F|u|n|c|t|i|o|n|<|A|2|,| |A|3|>|,| @12
+@20|F|u|n|c|t|i|o|n|<|F|u|n|c|t|i|o|n|<|A|1|,| |A|2|>|,| @28
+@20|F|u|n|c|t|i|o|n|<|A|1|,| |A|3|>@2| |{+0#00e0e07&| +0#0000000&|}+0#00e0e07&| +0#0000000&@32
+@4|i+0#00e0003&|n|t|e|r|f|a|c|e| +0#0000000&|S|<|A|1|,| |A|2|,| |A|3|>| |e+0#00e0003&|x|t|e|n|d|s| +0#0000000&@39
+@16|F|u|n|c|t|i|o|n|<|F|u|n|c|t|i|o|n|<|A|1|,| |F|u|n|c|t|i|o|n|<|A|2|,| |A|3|>@1|,| @18
+@20|F|u|n|c|t|i|o|n|<|F|u|n|c|t|i|o|n|<|A|1|,| |A|2|>|,| @28
+@20|F|u|n|c|t|i|o|n|<|A|1|,| |A|3|>@2| |{+0#00e0e07&| +0#0000000&|}+0#00e0e07&| +0#0000000&@32
+>}+0#00e0e07&| +0#0000000&@73
+@57|1|0|4|,|1| @8|B|o|t| 
diff --git a/runtime/syntax/testdir/input/java_lambda_expressions.java b/runtime/syntax/testdir/input/java_lambda_expressions.java
new file mode 100644
index 0000000000..5c9411e268
--- /dev/null
+++ b/runtime/syntax/testdir/input/java_lambda_expressions.java
@@ -0,0 +1,104 @@
+// VIM_TEST_SETUP let g:java_highlight_functions = 'style'
+
+
+import java.lang.annotation.ElementType;
+import java.util.function.BinaryOperator;
+import java.util.function.Function;
+
+class LambdaExpressionsTests
+{
+	<I1, C1, C2, T1, T2, T3, Z1, Z2, Z3, S1, S2, S3> void test()
+	{	// Schönfinkel's functions.
+		I<I1> i = x -> x;
+		C<C1, C2> c = x -> y -> x;
+		T<T1, T2, T3> t = f -> y -> x -> f.apply(x).apply(y);
+		Z<Z1, Z2, Z3> z = f -> g -> x -> f.apply(g.apply(x));
+		S<S1, S2, S3> s = f -> g -> x -> f.apply(x)
+						.apply(g.apply(x));
+
+		I<I1> i01 = (var x) -> x;
+		I<I1> i02 = (@Taggable var x) -> x;
+		I<I1> i03 = (@Taggable @Taggable var x) -> x;
+		I<I1> i04 = (final var x) -> x;
+		I<I1> i05 = (@Taggable final var x) -> x;
+		I<I1> i06 = (@Taggable @Taggable final var x) -> x;
+		I<I1> i07 = (I1 x) -> x;
+		I<I1> i08 = (@Taggable I1 x) -> x;
+		I<I1> i09 = (@Taggable @Taggable I1 x) -> x;
+		I<I1> i10 = (final I1 x) -> x;
+		I<I1> i11 = (@Taggable final I1 x) -> x;
+		I<I1> i12 = (@Taggable @Taggable final I1 x) -> x;
+
+		I<I1[]> ii01 = (I1... x) -> x;
+		I<I1[]> ii02 = (@Taggable I1... x) -> x;
+		I<I1[]> ii03 = (@Taggable @Taggable I1... x) -> x;
+		I<I1[]> ii04 = (final I1... x) -> x;
+		I<I1[]> ii05 = (@Taggable final I1... x) -> x;
+		I<I1[]> ii06 = (@Taggable @Taggable final I1... x) -> x;
+
+		BinaryOperator<I1> leftConst01 = (var x, var y) -> x;
+		BinaryOperator<I1> leftConst02 = (@Taggable var x,
+					@Taggable var y) -> x;
+		BinaryOperator<I1> leftConst03 = (@Taggable @Taggable var
+					x, @Taggable @Taggable var y) -> x;
+		BinaryOperator<I1> leftConst04 = (final var x,
+					final var y) -> x;
+		BinaryOperator<I1> leftConst05 = (@Taggable final
+					var x, @Taggable final var y) -> x;
+		BinaryOperator<I1> leftConst06 = (@Taggable
+					@Taggable final var x,
+					@Taggable
+					@Taggable final var y) -> x;
+		BinaryOperator<I1> leftConst07 = (I1 x, I1 y) -> x;
+		BinaryOperator<I1> leftConst08 = (@Taggable I1 x,
+					@Taggable I1 y) -> x;
+		BinaryOperator<I1> leftConst09 = (@Taggable @Taggable I1
+					x, @Taggable @Taggable I1 y) -> x;
+		BinaryOperator<I1> leftConst10 = (final I1 x,
+					final I1 y) -> x;
+		BinaryOperator<I1> leftConst11 = (@Taggable final
+					I1 x, @Taggable final I1 y) -> x;
+		BinaryOperator<I1> leftConst12 = (@Taggable
+					@Taggable final I1 x,
+					@Taggable
+					@Taggable final I1 y) -> x;
+
+		Runnable noOp = () -> {};
+		BinaryOperator<I1> leftConst = (x, y) -> x;
+		I<I1> id1 = (x) -> (x);
+		@SuppressWarnings("unchecked") I<I1> id2 =
+				((I<I<I1>>) (I<?>) (Function<I1,
+					I1> x) -> x).apply(switch (0) {
+				case ((int) (byte) 1) -> (I1 x) -> x;
+				default -> (@Taggable I1 x) -> x; });
+		C<C1, C2> const1 = (x) -> (y) -> (x);
+		C<C1, C2> const2 = switch(switch ("") {
+						case "->"->"(s)->(s)";
+						default->"default"; }) {
+			case ("->")->(var x)->(var y)->(x);
+			default->(@Taggable var x)->(@Taggable var y)
+				->(x);
+		};
+	}
+
+	@java.lang.annotation.Target(ElementType.PARAMETER)
+	@java.lang.annotation.Repeatable(Taggables.class)
+	@interface Taggable { String[] value() default ""; }
+
+	@java.lang.annotation.Target(ElementType.PARAMETER)
+	@interface Taggables { Taggable[] value(); }
+
+	interface I<A1> extends Function<A1, A1> { }
+	interface C<A1, A2> extends Function<A1, Function<A2, A1>> { }
+	interface T<A1, A2, A3> extends
+				Function<Function<A1, Function<A2, A3>>,
+					Function<A2,
+					Function<A1, A3>>> { }
+	interface Z<A1, A2, A3> extends Function<Function<A2, A3>,
+					Function<Function<A1, A2>,
+					Function<A1, A3>>> { }
+	interface S<A1, A2, A3> extends
+				Function<Function<A1, Function<A2, A3>>,
+					Function<Function<A1, A2>,
+					Function<A1, A3>>> { }
+}