add json scanner using RuleBasedScanner

1 files changed, 92 insertions, 0 deletions

diff --git a/lib/coderay/scanners/json5.rb b/lib/coderay/scanners/json5.rb
new file mode 100644
index 0000000..c68ebb7
--- /dev/null
+++ b/lib/coderay/scanners/json5.rb
@@ -0,0 +1,92 @@
+module CodeRay
+module Scanners
+  
+  # Scanner for JSON (JavaScript Object Notation).
+  class JSON5 < RuleBasedScanner
+    
+    register_for :json5
+    file_extension 'json'
+    
+    KINDS_NOT_LOC = [
+      :float, :char, :content, :delimiter,
+      :error, :integer, :operator, :value,
+    ]  # :nodoc:
+    
+    ESCAPE = / [bfnrt\\"\/] /x  # :nodoc:
+    UNICODE_ESCAPE = / u[a-fA-F0-9]{4} /x  # :nodoc:
+    KEY = / (?> (?: [^\\"]+ | \\. )* ) " \s* : /mx
+    
+    state :initial do
+      on %r/ \s+ /x, :space
+      
+      on %r/ [:,\[{\]}] /x, :operator
+      
+      on %r/ " (?=#{KEY}) /x, push(:key),    :delimiter
+      on %r/ " /x,            push(:string), :delimiter
+      
+      on %r/ true | false | null /x, :value
+      on %r/ -? (?: 0 | [1-9]\d* ) (?: \.\d+ (?: e[-+]? \d+ )? | e[-+]? \d+ ) /ix, :float
+      on %r/ -? (?: 0 | [1-9]\d* ) (?: e[+-] \d+ )? /ix, :integer
+    end
+    
+    state :key, :string do
+      on %r/ [^\\"]+ /x, :content
+      
+      on %r/ " /x, :delimiter, pop
+      
+      on %r/ \\ (?: #{ESCAPE} | #{UNICODE_ESCAPE} ) /x, :char
+      on %r/ \\. /mx, :content
+      on %r/ \\ /x, :error, pop
+    end
+    
+  protected
+    
+    def setup
+      @state = :initial
+    end
+    
+    # See http://json.org/ for a definition of the JSON lexic/grammar.
+    scan_tokens_code = <<-"RUBY"
+    def scan_tokens encoder, options
+      state = options[:state] || @state
+      
+      if [:string, :key].include? state
+        encoder.begin_group state
+      end
+      
+      states = [state]
+      
+      until eos?
+        
+        case state
+        
+#{ @code.chomp.gsub(/^/, '        ') }
+        else
+          raise_inspect 'Unknown state: %p' % [state], encoder
+          
+        end
+        
+      end
+      
+      if options[:keep_state]
+        @state = state
+      end
+      
+      if [:string, :key].include? state
+        encoder.end_group state
+      end
+      
+      encoder
+    end
+    RUBY
+    
+    if ENV['PUTS']
+      puts CodeRay.scan(scan_tokens_code, :ruby).terminal
+      puts "callbacks: #{callbacks.size}"
+    end
+    class_eval scan_tokens_code
+    
+  end
+  
+end
+end