1 files changed, 39 insertions, 8 deletions

diff --git a/lib/coderay/scanners/cpp.rb b/lib/coderay/scanners/cpp.rb
index 0b92ef9..6af5066 100644
--- a/lib/coderay/scanners/cpp.rb
+++ b/lib/coderay/scanners/cpp.rb
@@ -51,6 +51,10 @@ module Scanners
     def scan_tokens tokens, options
 
       state = :initial
+      label_expected = true
+      case_expected = false
+      label_expected_before_preproc_line = nil
+      in_preproc_line = false
 
       until eos?
 
@@ -61,8 +65,13 @@ module Scanners
 
         when :initial
 
-          if scan(/ \s+ | \\\n /x)
-            kind = :space
+          if match = scan(/ \s+ | \\\n /x)
+            if in_preproc_line && match != "\\\n" && match.index(?\n)
+              in_preproc_line = false
+              label_expected = label_expected_before_preproc_line
+            end
+            tokens << [match, :space]
+            next
 
           elsif scan(%r! // [^\n\\]* (?: \\. [^\n\\]* )* | /\* (?: .*? \*/ | .* ) !mx)
             kind = :comment
@@ -71,16 +80,29 @@ module Scanners
             match << scan_until(/ ^\# (?:elif|else|endif) .*? $ | \z /xm) unless eos?
             kind = :comment
 
-          elsif scan(/ [-+*=<>?:;,!&^|()\[\]{}~%]+ | \/=? | \.(?!\d) /x)
+          elsif match = scan(/ [-+*=<>?:;,!&^|()\[\]{}~%]+ | \/=? | \.(?!\d) /x)
+            label_expected = match =~ /[;\{\}]/
+            if case_expected
+              label_expected = true if match == ':'
+              case_expected = false
+            end
             kind = :operator
 
           elsif match = scan(/ [A-Za-z_][A-Za-z_0-9]* /x)
             kind = IDENT_KIND[match]
-            if kind == :ident and check(/:(?!:)/)
-              # FIXME: don't match a?b:c
+            if kind == :ident && label_expected && !in_preproc_line && scan(/:(?!:)/)
               kind = :label
-            elsif match == 'class'
-              state = :class_name_expected
+              match << matched
+            else
+              label_expected = false
+              if kind == :reserved
+                case match
+                when 'class'
+                  state = :class_name_expected
+                when 'case', 'default'
+                  case_expected = true
+                end
+              end
             end
 
           elsif scan(/\$/)
@@ -95,23 +117,30 @@ module Scanners
             state = :string
             kind = :delimiter
 
-          elsif scan(/#\s*(\w*)/)
+          elsif scan(/#[ \t]*(\w*)/)
             kind = :preprocessor
+            in_preproc_line = true
+            label_expected_before_preproc_line = label_expected
             state = :include_expected if self[1] == 'include'
 
           elsif scan(/ L?' (?: [^\'\n\\] | \\ #{ESCAPE} )? '? /ox)
+            label_expected = false
             kind = :char
 
           elsif scan(/0[xX][0-9A-Fa-f]+/)
+            label_expected = false
             kind = :hex
 
           elsif scan(/(?:0[0-7]+)(?![89.eEfF])/)
+            label_expected = false
             kind = :oct
 
           elsif scan(/(?:\d+)(?![.eEfF])L?L?/)
+            label_expected = false
             kind = :integer
 
           elsif scan(/\d[fF]?|\d*\.\d+(?:[eE][+-]?\d+)?[fF]?|\d+[eE][+-]?\d+[fF]?/)
+            label_expected = false
             kind = :float
 
           else
@@ -127,6 +156,7 @@ module Scanners
             tokens << ['"', :delimiter]
             tokens << [:close, :string]
             state = :initial
+            label_expected = false
             next
           elsif scan(/ \\ (?: #{ESCAPE} | #{UNICODE_ESCAPE} ) /mox)
             kind = :char
@@ -134,6 +164,7 @@ module Scanners
             tokens << [:close, :string]
             kind = :error
             state = :initial
+            label_expected = false
           else
             raise_inspect "else case \" reached; %p not handled." % peek(1), tokens
           end