1 files changed, 108 insertions, 0 deletions
diff --git a/app/app/syntax/lang/xml.rb b/app/app/syntax/lang/xml.rb
new file mode 100644
index 0000000..02ba798
--- /dev/null
+++ b/app/app/syntax/lang/xml.rb
@@ -0,0 +1,108 @@
+require 'app/syntax/common'
+
+module HH::Syntax
+
+  # A simple implementation of an XML lexer. It handles most cases. It is
+  # not a validating lexer, meaning it will happily process invalid XML without
+  # complaining.
+  class XML < Tokenizer
+
+    # Initialize the lexer.
+    def setup
+      @in_tag = false
+    end
+
+    # Step through a single iteration of the tokenization process. This will
+    # yield (potentially) many tokens, and possibly zero tokens.
+    def step
+      start_group :normal, matched if scan( /\s+/ )
+      if @in_tag
+        case
+          when scan( /([-\w]+):([-\w]+)/ )
+            start_group :namespace, subgroup(1)
+            start_group :punct, ":"
+            start_group :attribute, subgroup(2)
+          when scan( /\d+/ )
+            start_group :number, matched
+          when scan( /[-\w]+/ )
+            start_group :attribute, matched
+          when scan( %r{[/?]?>} )
+            @in_tag = false
+            start_group :punct, matched
+          when scan( /=/ )
+            start_group :punct, matched
+          when scan( /["']/ )
+            scan_string matched
+          else
+            append getch
+        end
+      elsif ( text = scan_until( /(?=[<&])/ ) )
+        start_group :normal, text unless text.empty?
+        if scan(/<!--.*?(-->|\Z)/m)
+          start_group :comment, matched
+        else
+          case peek(1)
+            when "<"
+              start_group :punct, getch
+              case peek(1)
+                when "?"
+                  append getch
+                when "/"
+                  append getch
+                when "!"
+                  append getch
+              end
+              start_group :normal, matched if scan( /\s+/ )
+              if scan( /([-\w]+):([-\w]+)/ )
+                start_group :namespace, subgroup(1)
+                start_group :punct, ":"
+                start_group :tag, subgroup(2)
+              elsif scan( /[-\w]+/ )
+                start_group :tag, matched
+              end
+              @in_tag = true
+            when "&"
+              if scan( /&\S{1,10};/ )
+                start_group :entity, matched
+              else
+                start_group :normal, scan( /&/ )
+              end
+          end
+        end
+      else
+        append scan_until( /\Z/ )
+      end
+    end
+
+    private
+
+      # Scan the string starting at the current position, with the given
+      # delimiter character.
+      def scan_string( delim )
+        start_group :punct, delim
+        match = /(?=[&\\]|#{delim})/
+        loop do
+          break unless ( text = scan_until( match ) )
+          start_group :string, text unless text.empty?
+          case peek(1)
+            when "&"
+              if scan( /&\S{1,10};/ )
+                start_group :entity, matched
+              else
+                start_group :string, getch
+              end
+            when "\\"
+              start_group :string, getch
+              append getch || ""
+            when delim
+              start_group :punct, getch
+              break
+          end
+        end
+      end
+
+  end
+
+  SYNTAX["xml"] = XML
+
+end