Highlight sigils and operators in Vim.

Sigil highlighting isn't perfect (especially how it handles ``&``) but
after having used it for a week I feel it to be considerably nicer than
nothing. As usual, if you don't like it, you can turn it off easily by
overriding the default highlighting.

Generics are not handled specially; this means that for something like
``S<T>``, the ``<`` and ``>`` are highlighted as operators. For myself,
I like this, and there is no way to make it properly context aware
without expanding the syntax matching enormously.

Also, special characters are highlighted properly in strings/chars, e.g.
``"\x00"`` or ``'\Ufedcba98'`` appropriately.

Author: chris-morgan

src/etc/vim/syntax/rust.vim

@@ -3,7 +3,7 @@
 " Maintainer:   Patrick Walton <[email protected]>
 " Maintainer:   Ben Blum <[email protected]>
 " Maintainer:   Chris Morgan <[email protected]>
-" Last Change:  2013 Jul 10
+" Last Change:  2013 Aug 1
 
 if version < 600
   syntax clear
@@ -17,7 +17,7 @@ syn keyword   rustOperator    as
 syn match     rustAssert      "\<assert\(\w\)*!" contained
 syn match     rustFail        "\<fail\(\w\)*!" contained
 syn keyword   rustKeyword     break copy do extern
-syn keyword   rustKeyword     for if impl let log
+syn keyword   rustKeyword     foreach in if impl let log
 syn keyword   rustKeyword     copy do extern
 syn keyword   rustKeyword     for impl let log
 syn keyword   rustKeyword     loop mod once priv pub
@@ -83,12 +83,26 @@ syn match     rustModPathSep  "::"
 syn match     rustFuncCall    "\w\(\w\)*("he=e-1,me=e-1
 syn match     rustFuncCall    "\w\(\w\)*::<"he=e-3,me=e-3 " foo::<T>();
 
+" This is merely a convention; note also the use of [A-Z], restricting it to
+" latin identifiers rather than the full Unicode uppercase. I have not used
+" [:upper:] as it depends upon 'noignorecase'
+"syn match     rustCapsIdent    display "[A-Z]\w\(\w\)*"
+
+syn match     rustOperator     display "\%(+\|-\|/\|*\|=\|\^\|&\||\|!\|>\|<\|%\)=\?"
+" This one isn't *quite* right, as we could have binary-& with a reference
+syn match     rustSigil        display /&\s\+[&~@*][^)= \t\r\n]/he=e-1,me=e-1
+syn match     rustSigil        display /[&~@*][^)= \t\r\n]/he=e-1,me=e-1
+" This isn't actually correct; a closure with no arguments can be `|| { }`.
+" Last, because the & in && isn't a sigil
+syn match     rustOperator     display "&&\|||"
+
 syn match     rustMacro       '\w\(\w\)*!' contains=rustAssert,rustFail
 syn match     rustMacro       '#\w\(\w\)*' contains=rustAssert,rustFail
 
 syn match     rustFormat      display "%\(\d\+\$\)\=[-+' #0*]*\(\d*\|\*\|\*\d\+\$\)\(\.\(\d*\|\*\|\*\d\+\$\)\)\=\([hlLjzt]\|ll\|hh\)\=\([aAbdiuoxXDOUfFeEgGcCsSpn?]\|\[\^\=.[^]]*\]\)" contained
 syn match     rustFormat      display "%%" contained
-syn region    rustString      start=+L\="+ skip=+\\\\\|\\"+ end=+"+ contains=rustTodo,rustFormat
+syn match     rustSpecial     display contained /\\\([nrt\\'"]\|x\x\{2}\|u\x\{4}\|U\x\{8}\)/
+syn region    rustString      start=+L\="+ skip=+\\\\\|\\"+ end=+"+ contains=rustTodo,rustFormat,rustSpecial
 
 syn region    rustAttribute   start="#\[" end="\]" contains=rustString,rustDeriving
 syn region    rustDeriving    start="deriving(" end=")" contained contains=rustTrait
@@ -114,13 +128,13 @@ syn match     rustFloat       display "\<[0-9][0-9_]*\.[0-9_]\+\%([eE][+-]\=[0-9
 syn match     rustFloat       display "\<[0-9][0-9_]*\.[0-9_]\+\%([eE][+-]\=[0-9_]\+\)\(f\|f32\|f64\)\>"
 
 " For the benefit of delimitMate
-syn region rustLifetimeCandidate display start=/&'\%(\([^'\\]\|\\\(['nrt\\\"]\|x\x\{2}\|u\x\{4}\|U\x\{8}\)\)'\)\@!/ end=/[[:cntrl:][:space:][:punct:]]\@=\|$/ contains=rustLifetime
+syn region rustLifetimeCandidate display start=/&'\%(\([^'\\]\|\\\(['nrt\\\"]\|x\x\{2}\|u\x\{4}\|U\x\{8}\)\)'\)\@!/ end=/[[:cntrl:][:space:][:punct:]]\@=\|$/ contains=rustSigil,rustLifetime
 syn region rustGenericRegion display start=/<\%('\|[^[cntrl:][:space:][:punct:]]\)\@=')\S\@=/ end=/>/ contains=rustGenericLifetimeCandidate
-syn region rustGenericLifetimeCandidate display start=/\%(<\|,\s*\)\@<='/ end=/[[:cntrl:][:space:][:punct:]]\@=\|$/ contains=rustLifetime
+syn region rustGenericLifetimeCandidate display start=/\%(<\|,\s*\)\@<='/ end=/[[:cntrl:][:space:][:punct:]]\@=\|$/ contains=rustSigil,rustLifetime
 
 "rustLifetime must appear before rustCharacter, or chars will get the lifetime highlighting
 syn match     rustLifetime    display "\'\%([^[:cntrl:][:space:][:punct:][:digit:]]\|_\)\%([^[:cntrl:][:punct:][:space:]]\|_\)*"
-syn match   rustCharacter   "'\([^'\\]\|\\\(['nrt\\\"]\|x\x\{2}\|u\x\{4}\|U\x\{8}\)\)'"
+syn match   rustCharacter   /'\([^'\\]\|\\\([nrt\\'"]\|x\x\{2}\|u\x\{4}\|U\x\{8}\)\)'/ contains=rustSpecial
 
 syn region    rustCommentML   start="/\*" end="\*/" contains=rustTodo
 syn region    rustComment     start="//" skip="\\$" end="$" contains=rustTodo keepend
@@ -140,7 +154,9 @@ hi def link rustBinNumber       rustNumber
 hi def link rustIdentifierPrime rustIdentifier
 hi def link rustTrait           rustType
 
+hi def link rustSigil         StorageClass
 hi def link rustFormat        Special
+hi def link rustSpecial       Special
 hi def link rustString        String
 hi def link rustCharacter     Character
 hi def link rustNumber        Number
@@ -152,6 +168,7 @@ hi def link rustOperator      Operator
 hi def link rustKeyword       Keyword
 hi def link rustConditional   Conditional
 hi def link rustIdentifier    Identifier
+hi def link rustCapsIdent     rustIdentifier
 hi def link rustModPath       Include
 hi def link rustModPathSep    Delimiter
 hi def link rustFuncName      Function