use different key/value heuristic in JSON scanner

1 files changed, 11 insertions, 12 deletions

diff --git a/lib/coderay/scanners/json.rb b/lib/coderay/scanners/json.rb
index 4e0f462..3754a9b 100644
--- a/lib/coderay/scanners/json.rb
+++ b/lib/coderay/scanners/json.rb
@@ -14,15 +14,17 @@ module Scanners
     
     ESCAPE = / [bfnrt\\"\/] /x  # :nodoc:
     UNICODE_ESCAPE = / u[a-fA-F0-9]{4} /x  # :nodoc:
+    KEY = / (?> (?: [^\\"]+ | \\. )* ) " \s* : /x
     
   protected
     
+    def setup
+      @state = :initial
+    end
+    
     # See http://json.org/ for a definition of the JSON lexic/grammar.
     def scan_tokens encoder, options
-      
-      state = :initial
-      stack = []
-      key_expected = false
+      state = options[:state] || @state
       
       until eos?
         
@@ -32,18 +34,11 @@ module Scanners
           if match = scan(/ \s+ /x)
             encoder.text_token match, :space
           elsif match = scan(/"/)
-            state = key_expected ? :key : :string
+            state = check(/#{KEY}/o) ? :key : :string
             encoder.begin_group state
             encoder.text_token match, :delimiter
           elsif match = scan(/ [:,\[{\]}] /x)
             encoder.text_token match, :operator
-            case match
-            when ':' then key_expected = false
-            when ',' then key_expected = true if stack.last == :object
-            when '{' then stack << :object; key_expected = true
-            when '[' then stack << :array
-            when '}', ']' then stack.pop  # no error recovery, but works for valid JSON
-            end
           elsif match = scan(/ true | false | null /x)
             encoder.text_token match, :value
           elsif match = scan(/ -? (?: 0 | [1-9]\d* ) /x)
@@ -82,6 +77,10 @@ module Scanners
         end
       end
       
+      if options[:keep_state]
+        @state = state
+      end
+      
       if [:string, :key].include? state
         encoder.end_group state
       end