[PATCH] Some love for Java syntax highlighting

[Benno Schulenberg]

From: Devin Hussey <husseydevin@gmail.com>

  [Does anyone here use Java?  Are these changes an improvement
   over the current Java syntax?  --  Benno]

This is much better than the unsightly highlighting we had before.

- I changed the colors to fit in with the nanorc style, which I happen to like
  a lot. No more red strings.
- It supports current keywords such as enum and module
- It supports number/character literals, and no longer chokes on escapes
- Colors are easier to read, and there are fewer clashes (e.g. string switching)
- CONSTANTS_ARE_HIGHLIGHTED_LIKE_C
- @Annotations and @javadoc keywords are also highlighted now.
- It recognizes .aidl files and files starting with "^package foo.*;" as Java.

Signed-off-by: Devin Hussey <husseydevin@gmail.com>
---
 syntax/java.nanorc | 40 ++++++++++++++++++++++++++++------------
 1 file changed, 28 insertions(+), 12 deletions(-)

diff --git a/syntax/java.nanorc b/syntax/java.nanorc
index 5bb294f4..312e14a7 100644
--- a/syntax/java.nanorc
+++ b/syntax/java.nanorc
@@ -1,16 +1,32 @@
 ## Here is an example for Java.
-
-syntax java "\.java$"
-magic "Java "
+syntax java "\.(aidl|java)$"
+# package foo.(...);
+header "^[[:space:]]*package[[:space:]]+[a-zA-Z][a-zA-Z0-9]*\..+;$"
+# XXX: Don't Java files identify as "C source, ASCII text"?
+magic ".*Java[^S].*"
 comment "//"
 
-color green 
"\<(boolean|byte|char|double|float|int|long|new|short|this|transient|void)\>"
-color red 
"\<(break|case|catch|continue|default|do|else|finally|for|if|return|switch|throw|try|while)\>"
-color cyan 
"\<(abstract|class|extends|final|implements|import|instanceof|interface|native)\>"
-color cyan 
"\<(package|private|protected|public|static|strictfp|super|synchronized|throws|volatile)\>"
-color red ""[^"]*""
-color yellow "\<(true|false|null)\>"
-color blue "//.*"
-color blue start="/\*" end="\*/"
-color brightblue start="/\*\*" end="\*/"
+# Constants
+color brightred "\<[A-Z_][A-Z0-9_]+\>"
+# Keywords
+color yellow 
"\<(boolean|byte|char|double|float|int|long|new|short|transient|var|void)\>"
+color magenta 
"\<(assert|break|case|catch|continue|default|do|else|finally|for|if|return|switch|throw|try|while)\>"
+color green 
"\<(abstract|class|enum|exports|extends|final|implements|import|instanceof|interface|module|native|requires)\>"
+color green 
"\<(package|private|protected|public|static|strictfp|super|synchronized|throws|volatile)\>"
+# Weird unused keywords
+color brightwhite,red "\<(const|goto)\>"
+
+# Quotes and literals
+color brightmagenta ""(\\"|[^"])*""
+color brightmagenta "'([^'\]|(\\["'abfnrtv\\]))'" "'\\(([0-3]?[0-7]{1,2}))'" 
"'\\x[0-9A-Fa-f]{1,2}'"
+# Number literals
+color brightmagenta 
"\<(0b[01][01_]*|0[0-7][0-7_]*|[[:digit:]]+(\.[[:digit:]_]*)?|\.[[:digit:]_]+)[lLFfDd]?\>|(-?)(\<0[xX][[:xdigit:]_]+|(\<[[:digit:]_]+(\.[[:digit:]_]*)?|\.[[:digit:]_]+)([eE][-+]?[[:digit:]_]+)?)\>"
+color brightmagenta "\<(true|false|null)\>"
+
+# Comments
+color brightblue "//.*"
+color brightblue start="/\*" end="\*/"
+# Annotations or Javadoc keywords
+color cyan "@[[:space:]]*\<[A-Za-z][A-Za-z0-9_]*\>"
+
 color ,green "[[:space:]]+$"
-- 
2.19.0