comparison vendor/plugins/coderay-0.9.2/lib/coderay/.svn/text-base/tokens.rb.svn-base @ 0:513646585e45

* Import Redmine trunk SVN rev 3859

+module CodeRay
+
+  # = Tokens
+  #
+  # The Tokens class represents a list of tokens returnd from
+  # a Scanner.
+  #
+  # A token is not a special object, just a two-element Array
+  # consisting of
+  # * the _token_ _kind_ (a Symbol representing the type of the token)
+  # * the _token_ _text_ (the original source of the token in a String)
+  #
+  # A token looks like this:
+  #
+  #   [:comment, '# It looks like this']
+  #   [:float, '3.1415926']
+  #   [:error, '$^']
+  #
+  # Some scanners also yield some kind of sub-tokens, represented by special
+  # token texts, namely :open and :close .
+  #
+  # The Ruby scanner, for example, splits "a string" into:
+  #
+  #  [
+  #   [:open, :string],
+  #   [:delimiter, '"'],
+  #   [:content, 'a string'],
+  #   [:delimiter, '"'],
+  #   [:close, :string]
+  #  ]
+  #
+  # Tokens is also the interface between Scanners and Encoders:
+  # The input is split and saved into a Tokens object. The Encoder
+  # then builds the output from this object.
+  #
+  # Thus, the syntax below becomes clear:
+  #
+  #   CodeRay.scan('price = 2.59', :ruby).html
+  #   # the Tokens object is here -------^
+  #
+  # See how small it is? ;)
+  #
+  # Tokens gives you the power to handle pre-scanned code very easily:
+  # You can convert it to a webpage, a YAML file, or dump it into a gzip'ed string
+  # that you put in your DB.
+  #
+  # Tokens' subclass TokenStream allows streaming to save memory.
+  class Tokens < Array
+    
+    # The Scanner instance that created the tokens.
+    attr_accessor :scanner
+    
+    # Whether the object is a TokenStream.
+    #
+    # Returns false.
+    def stream?
+      false
+    end
+
+    # Iterates over all tokens.
+    #
+    # If a filter is given, only tokens of that kind are yielded.
+    def each kind_filter = nil, &block
+      unless kind_filter
+        super(&block)
+      else
+        super() do |text, kind|
+          next unless kind == kind_filter
+          yield text, kind
+        end
+      end
+    end
+
+    # Iterates over all text tokens.
+    # Range tokens like [:open, :string] are left out.
+    #
+    # Example:
+    #   tokens.each_text_token { |text, kind| text.replace html_escape(text) }
+    def each_text_token
+      each do |text, kind|
+        next unless text.is_a? ::String
+        yield text, kind
+      end
+    end
+
+    # Encode the tokens using encoder.
+    #
+    # encoder can be
+    # * a symbol like :html oder :statistic
+    # * an Encoder class
+    # * an Encoder object
+    #
+    # options are passed to the encoder.
+    def encode encoder, options = {}
+      unless encoder.is_a? Encoders::Encoder
+        unless encoder.is_a? Class
+          encoder_class = Encoders[encoder]
+        end
+        encoder = encoder_class.new options
+      end
+      encoder.encode_tokens self, options
+    end
+
+
+    # Turn into a string using Encoders::Text.
+    #
+    # +options+ are passed to the encoder if given.
+    def to_s options = {}
+      encode :text, options
+    end
+
+    # Redirects unknown methods to encoder calls.
+    #
+    # For example, if you call +tokens.html+, the HTML encoder
+    # is used to highlight the tokens.
+    def method_missing meth, options = {}
+      Encoders[meth].new(options).encode_tokens self
+    end
+
+    # Returns the tokens compressed by joining consecutive
+    # tokens of the same kind.
+    #
+    # This can not be undone, but should yield the same output
+    # in most Encoders.  It basically makes the output smaller.
+    #
+    # Combined with dump, it saves space for the cost of time.
+    #
+    # If the scanner is written carefully, this is not required -
+    # for example, consecutive //-comment lines could already be
+    # joined in one comment token by the Scanner.
+    def optimize
+      last_kind = last_text = nil
+      new = self.class.new
+      for text, kind in self
+        if text.is_a? String
+          if kind == last_kind
+            last_text << text
+          else
+            new << [last_text, last_kind] if last_kind
+            last_text = text
+            last_kind = kind
+          end
+        else
+          new << [last_text, last_kind] if last_kind
+          last_kind = last_text = nil
+          new << [text, kind]
+        end
+      end
+      new << [last_text, last_kind] if last_kind
+      new
+    end
+
+    # Compact the object itself; see optimize.
+    def optimize!
+      replace optimize
+    end
+    
+    # Ensure that all :open tokens have a correspondent :close one.
+    #
+    # TODO: Test this!
+    def fix
+      tokens = self.class.new
+      # Check token nesting using a stack of kinds.
+      opened = []
+      for type, kind in self
+        case type
+        when :open
+          opened.push [:close, kind]
+        when :begin_line
+          opened.push [:end_line, kind]
+        when :close, :end_line
+          expected = opened.pop
+          if [type, kind] != expected
+            # Unexpected :close; decide what to do based on the kind:
+            # - token was never opened: delete the :close (just skip it)
+            next unless opened.rindex expected
+            # - token was opened earlier: also close tokens in between
+            tokens << token until (token = opened.pop) == expected
+          end
+        end
+        tokens << [type, kind]
+      end
+      # Close remaining opened tokens
+      tokens << token while token = opened.pop
+      tokens
+    end
+    
+    def fix!
+      replace fix
+    end
+    
+    # TODO: Scanner#split_into_lines
+    # 
+    # Makes sure that:
+    # - newlines are single tokens
+    #   (which means all other token are single-line)
+    # - there are no open tokens at the end the line
+    #
+    # This makes it simple for encoders that work line-oriented,
+    # like HTML with list-style numeration.
+    def split_into_lines
+      raise NotImplementedError
+    end
+
+    def split_into_lines!
+      replace split_into_lines
+    end
+
+    # Dumps the object into a String that can be saved
+    # in files or databases.
+    #
+    # The dump is created with Marshal.dump;
+    # In addition, it is gzipped using GZip.gzip.
+    #
+    # The returned String object includes Undumping
+    # so it has an #undump method. See Tokens.load.
+    #
+    # You can configure the level of compression,
+    # but the default value 7 should be what you want
+    # in most cases as it is a good compromise between
+    # speed and compression rate.
+    #
+    # See GZip module.
+    def dump gzip_level = 7
+      require 'coderay/helpers/gzip_simple'
+      dump = Marshal.dump self
+      dump = dump.gzip gzip_level
+      dump.extend Undumping
+    end
+
+    # The total size of the tokens.
+    # Should be equal to the input size before
+    # scanning.
+    def text_size
+      size = 0
+      each_text_token do |t, k|
+        size + t.size
+      end
+      size
+    end
+
+    # The total size of the tokens.
+    # Should be equal to the input size before
+    # scanning.
+    def text
+      map { |t, k| t if t.is_a? ::String }.join
+    end
+
+    # Include this module to give an object an #undump
+    # method.
+    #
+    # The string returned by Tokens.dump includes Undumping.
+    module Undumping
+      # Calls Tokens.load with itself.
+      def undump
+        Tokens.load self
+      end
+    end
+
+    # Undump the object using Marshal.load, then
+    # unzip it using GZip.gunzip.
+    #
+    # The result is commonly a Tokens object, but
+    # this is not guaranteed.
+    def Tokens.load dump
+      require 'coderay/helpers/gzip_simple'
+      dump = dump.gunzip
+      @dump = Marshal.load dump
+    end
+
+  end
+
+
+  # = TokenStream
+  #
+  # The TokenStream class is a fake Array without elements.
+  #
+  # It redirects the method << to a block given at creation.
+  #
+  # This allows scanners and Encoders to use streaming (no
+  # tokens are saved, the input is highlighted the same time it
+  # is scanned) with the same code.
+  #
+  # See CodeRay.encode_stream and CodeRay.scan_stream
+  class TokenStream < Tokens
+
+    # Whether the object is a TokenStream.
+    #
+    # Returns true.
+    def stream?
+      true
+    end
+
+    # The Array is empty, but size counts the tokens given by <<.
+    attr_reader :size
+
+    # Creates a new TokenStream that calls +block+ whenever
+    # its << method is called.
+    #
+    # Example:
+    #
+    #   require 'coderay'
+    #   
+    #   token_stream = CodeRay::TokenStream.new do |kind, text|
+    #     puts 'kind: %s, text size: %d.' % [kind, text.size]
+    #   end
+    #   
+    #   token_stream << [:regexp, '/\d+/']
+    #   #-> kind: rexpexp, text size: 5.
+    #
+    def initialize &block
+      raise ArgumentError, 'Block expected for streaming.' unless block
+      @callback = block
+      @size = 0
+    end
+
+    # Calls +block+ with +token+ and increments size.
+    #
+    # Returns self.
+    def << token
+      @callback.call(*token)
+      @size += 1
+      self
+    end
+
+    # This method is not implemented due to speed reasons. Use Tokens.
+    def text_size
+      raise NotImplementedError,
+        'This method is not implemented due to speed reasons.'
+    end
+
+    # A TokenStream cannot be dumped. Use Tokens.
+    def dump
+      raise NotImplementedError, 'A TokenStream cannot be dumped.'
+    end
+
+    # A TokenStream cannot be optimized. Use Tokens.
+    def optimize
+      raise NotImplementedError, 'A TokenStream cannot be optimized.'
+    end
+
+  end
+
+end
+
+if $0 == __FILE__
+  $VERBOSE = true
+  $: << File.join(File.dirname(__FILE__), '..')
+  eval DATA.read, nil, $0, __LINE__ + 4
+end
+
+__END__
+require 'test/unit'
+
+class TokensTest < Test::Unit::TestCase
+  
+  def test_creation
+    assert CodeRay::Tokens < Array
+    tokens = nil
+    assert_nothing_raised do
+      tokens = CodeRay::Tokens.new
+    end
+    assert_kind_of Array, tokens
+  end
+  
+  def test_adding_tokens
+    tokens = CodeRay::Tokens.new
+    assert_nothing_raised do
+      tokens << ['string', :type]
+      tokens << ['()', :operator]
+    end
+    assert_equal tokens.size, 2
+  end
+  
+  def test_dump_undump
+    tokens = CodeRay::Tokens.new
+    assert_nothing_raised do
+      tokens << ['string', :type]
+      tokens << ['()', :operator]
+    end
+    tokens2 = nil
+    assert_nothing_raised do
+      tokens2 = tokens.dump.undump
+    end
+    assert_equal tokens, tokens2
+  end
+  
+end