1 files changed, 348 insertions, 0 deletions
diff --git a/lib/rdoc/markup/simple_markup/inline.rb b/lib/rdoc/markup/simple_markup/inline.rb
new file mode 100644
index 0000000000..684ff4b275
--- /dev/null
+++ b/lib/rdoc/markup/simple_markup/inline.rb
@@ -0,0 +1,348 @@
+module SM
+
+  # We manage a set of attributes. Each attribute has a symbol name
+  # and a bit value
+
+  class Attribute
+    SPECIAL = 1
+
+    @@name_to_bitmap = { :_SPECIAL_ => SPECIAL }
+    @@next_bitmap = 2
+
+    def Attribute.bitmap_for(name)
+      bitmap = @@name_to_bitmap[name]
+      if !bitmap
+        bitmap = @@next_bitmap
+        @@next_bitmap <<= 1
+        @@name_to_bitmap[name] = bitmap
+      end
+      bitmap
+    end
+
+    def Attribute.as_string(bitmap)
+      return "none" if bitmap.zero?
+      res = []
+      @@name_to_bitmap.each do |name, bit|
+        res << name if (bitmap & bit) != 0
+      end
+      res.join(",")
+    end
+
+    def Attribute.each_name_of(bitmap)
+      @@name_to_bitmap.each do |name, bit|
+        next if bit == SPECIAL
+        yield name.to_s if (bitmap & bit) != 0
+      end
+    end
+  end
+
+
+  # An AttrChanger records a change in attributes. It contains
+  # a bitmap of the attributes to turn on, and a bitmap of those to
+  # turn off
+
+  AttrChanger = Struct.new(:turn_on, :turn_off)
+  class AttrChanger
+    def to_s
+      "Attr: +#{Attribute.as_string(@turn_on)}/-#{Attribute.as_string(@turn_on)}"
+    end
+  end
+
+  # An array of attributes which parallels the characters in a string
+  class AttrSpan
+    def initialize(length)
+      @attrs = Array.new(length, 0)
+    end
+
+    def set_attrs(start, length, bits)
+      for i in start ... (start+length)
+        @attrs[i] |= bits
+      end
+    end
+
+    def [](n)
+      @attrs[n]
+    end
+  end
+
+  ##
+  # Hold details of a special sequence
+
+  class Special
+    attr_reader   :type
+    attr_accessor :text
+
+    def initialize(type, text)
+      @type, @text = type, text
+    end
+
+    def ==(o)
+      self.text == o.text && self.type == o.type
+    end
+
+    def to_s
+      "Special: type=#{type}, text=#{text.dump}"
+    end
+  end
+  
+  class AttributeManager
+
+    NULL = "\000".freeze
+
+    ##
+    # We work by substituting non-printing characters in to the
+    # text. For now I'm assuming that I can substitute
+    # a character in the range 0..8 for a 7 bit character
+    # without damaging the encoded string, but this might
+    # be optimistic
+    #
+
+=begin
+    ATTR_FLAG  = 001
+    A_START    = 002
+    A_END      = 003
+    A_SPECIAL_START = 005
+    A_SPECIAL_END   = 006
+
+    START_ATTR   = ATTR_FLAG.chr + A_START.chr
+    END_ATTR     = ATTR_FLAG.chr + A_END.chr
+
+    START_SPECIAL = ATTR_FLAG.chr + A_SPECIAL_START.chr
+    END_SPECIAL   = ATTR_FLAG.chr + A_SPECIAL_END.chr
+
+=end
+    A_PROTECT  = 004
+    PROTECT_ATTR  = A_PROTECT.chr
+
+    # This maps delimiters that occur around words (such as
+    # *bold* or +tt+) where the start and end delimiters
+    # and the same. This lets us optimize the regexp
+    MATCHING_WORD_PAIRS = {}
+
+    # And this is used when the delimiters aren't the same. In this
+    # case the hash maps a pattern to the attribute character
+    WORD_PAIR_MAP = {}
+
+    # This maps HTML tags to the corresponding attribute char
+    HTML_TAGS = {}
+
+    # And this maps _special_ sequences to a name. A special sequence
+    # is something like a WikiWord
+    SPECIAL = {}
+
+    # Return an attribute object with the given turn_on
+    # and turn_off bits set
+
+    def attribute(turn_on, turn_off)
+      AttrChanger.new(turn_on, turn_off)
+    end
+
+
+    def change_attribute(current, new)
+      diff = current ^ new
+      attribute(new & diff, current & diff)
+    end
+
+    def changed_attribute_by_name(current_set, new_set)
+      current = new = 0
+      current_set.each {|name| current |= Attribute.bitmap_for(name) }
+      new_set.each {|name| new |= Attribute.bitmap_for(name) }
+      change_attribute(current, new)
+    end
+
+    def copy_string(start_pos, end_pos)
+      res = @str[start_pos...end_pos]
+      res.gsub!(/\000/, '')
+      res
+    end
+
+    # Map attributes like <b>text</b>to the sequence \001\002<char>\001\003<char>,
+    # where <char> is a per-attribute specific character
+
+    def convert_attrs(str, attrs)
+      # first do matching ones
+      tags = MATCHING_WORD_PAIRS.keys.join("")
+      re = "(^|\\W)([#{tags}])([A-Za-z_]+?)\\2(\\W|\$)"
+#      re = "(^|\\W)([#{tags}])(\\S+?)\\2(\\W|\$)"
+      1 while str.gsub!(Regexp.new(re)) {
+        attr = MATCHING_WORD_PAIRS[$2];
+        attrs.set_attrs($`.length + $1.length + $2.length, $3.length, attr)
+        $1 + NULL*$2.length + $3 + NULL*$2.length + $4
+      }
+
+      # then non-matching
+      unless WORD_PAIR_MAP.empty?
+        WORD_PAIR_MAP.each do |regexp, attr|
+          str.gsub!(regexp) { 
+            attrs.set_attrs($`.length + $1.length, $2.length, attr)
+            NULL*$1.length + $2 + NULL*$3.length
+          }
+        end
+      end
+    end
+
+    def convert_html(str, attrs)
+      tags = HTML_TAGS.keys.join("|")
+      re = "<(#{tags})>(.*?)</\\1>"
+      1 while str.gsub!(Regexp.new(re, Regexp::IGNORECASE)) {
+        attr = HTML_TAGS[$1.downcase]
+        html_length = $1.length + 2
+        seq = NULL * html_length
+        attrs.set_attrs($`.length + html_length, $2.length, attr)
+        seq + $2 + seq + NULL
+      }
+    end
+
+    def convert_specials(str, attrs)
+      unless SPECIAL.empty?
+        SPECIAL.each do |regexp, attr|
+          str.scan(regexp) do
+            attrs.set_attrs($`.length, $1.length, attr | Attribute::SPECIAL)
+          end
+        end
+      end
+    end
+
+    # A \ in front of a character that would normally be
+    # processed turns off processing. We do this by turning
+    # \< into <#{PROTECT}
+    
+    PROTECTABLE = [ "<" << "\\" ]  #"
+
+
+    def mask_protected_sequences
+      protect_pattern = Regexp.new("\\\\([#{Regexp.escape(PROTECTABLE.join(''))}])")
+      @str.gsub!(protect_pattern, "\\1#{PROTECT_ATTR}")
+    end
+
+    def unmask_protected_sequences
+      @str.gsub!(/(.)#{PROTECT_ATTR}/, '\1')
+    end
+
+    def initialize
+      add_word_pair("*", "*", :BOLD)
+      add_word_pair("_", "_", :EM)
+      add_word_pair("+", "+", :TT)
+      
+      add_html("em", :EM)
+      add_html("i",  :EM)
+      add_html("b",  :BOLD)
+      add_html("tt", :TT)
+    end
+
+    def add_word_pair(start, stop, name)
+      raise "Word flags may not start '<'" if start[0] == ?<
+      bitmap = Attribute.bitmap_for(name)
+      if start == stop
+        MATCHING_WORD_PAIRS[start] = bitmap
+      else
+        pattern = Regexp.new("(" + Regexp.escape(start) + ")" +
+#                             "([A-Za-z]+)" +
+                             "(\\S+)" +
+                             "(" + Regexp.escape(stop) +")")
+        WORD_PAIR_MAP[pattern] = bitmap
+      end
+      PROTECTABLE << start[0,1]
+      PROTECTABLE.uniq!
+    end
+
+    def add_html(tag, name)
+      HTML_TAGS[tag.downcase] = Attribute.bitmap_for(name)
+    end
+
+    def add_special(pattern, name)
+      SPECIAL[pattern] = Attribute.bitmap_for(name)
+    end
+
+    def flow(str)
+      @str = str
+      @attrs = AttrSpan.new(str.length)
+
+      puts("Before flow, str='#{@str.dump}'") if $DEBUG
+      mask_protected_sequences
+      convert_attrs(@str, @attrs)
+      convert_html(@str, @attrs)
+      convert_specials(str, @attrs)
+      unmask_protected_sequences
+      puts("After flow, str='#{@str.dump}'") if $DEBUG
+      return split_into_flow
+    end
+
+    def display_attributes
+      puts
+      puts @str.tr(NULL, "!")
+      bit = 1
+      16.times do |bno|
+        line = ""
+        @str.length.times do |i|
+          if (@attrs[i] & bit) == 0
+            line << " "
+          else
+            if bno.zero?
+              line << "S"
+            else
+              line << ("%d" % (bno+1))
+            end
+          end
+        end
+        puts(line) unless line =~ /^ *$/
+        bit <<= 1
+      end
+    end
+
+    def split_into_flow
+
+      display_attributes if $DEBUG
+
+      res = []
+      current_attr = 0
+      str = ""
+
+      
+      str_len = @str.length
+
+      # skip leading invisible text
+      i = 0
+      i += 1 while i < str_len and @str[i].zero?
+      start_pos = i
+
+      # then scan the string, chunking it on attribute changes
+      while i < str_len
+        new_attr = @attrs[i]
+        if new_attr != current_attr
+          if i > start_pos
+            res << copy_string(start_pos, i)
+            start_pos = i
+          end
+
+          res << change_attribute(current_attr, new_attr)
+          current_attr = new_attr
+
+          if (current_attr & Attribute::SPECIAL) != 0
+            i += 1 while i < str_len and (@attrs[i] & Attribute::SPECIAL) != 0
+            res << Special.new(current_attr, copy_string(start_pos, i))
+            start_pos = i
+            next
+          end
+        end
+
+        # move on, skipping any invisible characters
+        begin
+          i += 1
+        end while i < str_len and @str[i].zero?
+      end
+      
+      # tidy up trailing text
+      if start_pos < str_len
+        res << copy_string(start_pos, str_len)
+      end
+
+      # and reset to all attributes off
+      res << change_attribute(current_attr, 0) if current_attr != 0
+
+      return res
+    end
+
+  end
+
+end