A prototype implementation of "inside Regexp" detection for the Ruby scanner. Would be nice for diffs.

1 files changed, 455 insertions, 0 deletions

diff --git a/etc/todo/scanners/ruby-inside-regexp-detection.rb b/etc/todo/scanners/ruby-inside-regexp-detection.rb
new file mode 100644
index 0000000..c68611a
--- /dev/null
+++ b/etc/todo/scanners/ruby-inside-regexp-detection.rb
@@ -0,0 +1,455 @@
+module CodeRay
+module Scanners
+
+  # This scanner is really complex, since Ruby _is_ a complex language!
+  #
+  # It tries to highlight 100% of all common code,
+  # and 90% of strange codes.
+  #
+  # It is optimized for HTML highlighting, and is not very useful for
+  # parsing or pretty printing.
+  #
+  # For now, I think it's better than the scanners in VIM or Syntax, or
+  # any highlighter I was able to find, except Caleb's RubyLexer.
+  #
+  # I hope it's also better than the rdoc/irb lexer.
+  # 
+  # Alias: +irb+
+  class Ruby < Scanner
+
+    register_for :ruby
+    file_extension 'rb'
+
+    helper :patterns
+    
+    unless defined? EncodingError
+      EncodingError = Class.new Exception  # :nodoc:
+    end
+    
+  protected
+    
+    def setup
+      @state = :initial
+    end
+    
+    def scan_tokens encoder, options
+      
+      patterns = Patterns  # avoid constant lookup
+      
+      state = @state
+      if state.instance_of? patterns::StringState
+        encoder.begin_group state.type
+      end
+      
+      last_state = nil
+      
+      method_call_expected = false
+      value_expected = true
+      
+      heredocs = nil
+      inline_block_stack = nil
+      inline_block_curly_depth = 0
+      
+      # def_object_stack = nil
+      # def_object_paren_depth = 0
+      
+      unicode = string.respond_to?(:encoding) && string.encoding.name == 'UTF-8'
+      
+      until eos?
+
+        if state.instance_of? patterns::StringState
+
+          match = scan_until(state.pattern) || scan_until(/\z/)
+          encoder.text_token match, :content unless match.empty?
+          break if eos?
+
+          if state.heredoc and self[1]  # end of heredoc
+            match = getch.to_s
+            match << scan_until(/$/) unless eos?
+            encoder.text_token match, :delimiter
+            encoder.end_group state.type
+            state = state.next_state
+            next
+          end
+
+          case match = getch
+
+          when state.delim
+            if state.paren_depth
+              state.paren_depth -= 1
+              if state.paren_depth > 0
+                encoder.text_token match, :nesting_delimiter
+                next
+              end
+            end
+            encoder.text_token match, :delimiter
+            if state.type == :regexp and not eos?
+              modifiers = scan(/#{patterns::REGEXP_MODIFIERS}/ox)
+              encoder.text_token modifiers, :modifier unless modifiers.empty?
+            end
+            encoder.end_group state.type
+            value_expected = false
+            state = state.next_state
+
+          when '\\'
+            if state.interpreted
+              if esc = scan(/ #{patterns::ESCAPE} /ox)
+                encoder.text_token match + esc, :char
+              else
+                encoder.text_token match, :error
+              end
+            else
+              case m = getch
+              when state.delim, '\\'
+                encoder.text_token match + m, :char
+              when nil
+                encoder.text_token match, :content
+              else
+                encoder.text_token match + m, :content
+              end
+            end
+
+          when '#'
+            case peek(1)
+            when '{'
+              inline_block_stack ||= []
+              inline_block_stack << [state, inline_block_curly_depth, heredocs]
+              value_expected = true
+              state = :initial
+              inline_block_curly_depth = 1
+              encoder.begin_group :inline
+              encoder.text_token match + getch, :inline_delimiter
+            when '$', '@'
+              encoder.text_token match, :escape
+              last_state = state
+              state = :initial
+            else
+              raise_inspect 'else-case # reached; #%p not handled' % 
+                [peek(1)], encoder
+            end
+
+          when state.opening_paren
+            state.paren_depth += 1
+            encoder.text_token match, :nesting_delimiter
+
+          when /#{patterns::REGEXP_SYMBOLS}/ox
+            encoder.text_token match, :function
+
+          else
+            raise_inspect 'else-case " reached; %p not handled, state = %p' %
+              [match, state], encoder
+
+          end
+
+        else
+
+          if match = scan(/[ \t\f]+/)
+            match << scan(/\s*/) unless eos? || heredocs
+            value_expected = true if match.index(?\n)
+            encoder.text_token match, :space
+            
+          elsif match = scan(/\\?\n/)
+            if match == "\n"
+              value_expected = true
+              state = :initial if state == :undef_comma_expected
+            end
+            if heredocs
+              unscan  # heredoc scanning needs \n at start
+              state = heredocs.shift
+              encoder.begin_group state.type
+              heredocs = nil if heredocs.empty?
+              next
+            else
+              match << scan(/\s*/) unless eos?
+            end
+            encoder.text_token match, :space
+          
+          elsif bol? && match = scan(/\#!.*/)
+            encoder.text_token match, :doctype
+            
+          elsif match = scan(/\#.*/) or
+             (bol? and match = scan(/#{patterns::RUBYDOC_OR_DATA}/o))
+            encoder.text_token match, :comment
+
+          elsif state == :initial
+
+            # IDENTS #
+            if !method_call_expected and
+               match = scan(unicode ? /#{patterns::METHOD_NAME}/uo :
+                                      /#{patterns::METHOD_NAME}/o)
+              value_expected = false
+              kind = patterns::IDENT_KIND[match]
+              if kind == :ident
+                if match[/^[A-Z]/] && !match[/[!?]$/] && !match?(/\(/)
+                  kind = :constant
+                end
+              elsif kind == :reserved
+                state = patterns::KEYWORD_NEW_STATE[match]
+                value_expected = true if patterns::KEYWORDS_EXPECTING_VALUE[match]
+              end
+              value_expected = true if !value_expected && check(/#{patterns::VALUE_FOLLOWS}/o)
+              encoder.text_token match, kind
+            
+            elsif method_call_expected and
+               match = scan(unicode ? /#{patterns::METHOD_AFTER_DOT}/uo :
+                                      /#{patterns::METHOD_AFTER_DOT}/o)
+              if method_call_expected == '::' && match[/^[A-Z]/] && !match?(/\(/)
+                encoder.text_token match, :constant
+              else
+                encoder.text_token match, :ident
+              end
+              method_call_expected = false
+              value_expected = check(/#{patterns::VALUE_FOLLOWS}/o)
+
+            # OPERATORS #
+            elsif not method_call_expected and match = scan(/ \.\.\.? | (\.|::) | [,\(\)\[\]\{\}] | ==?=? /x)
+              value_expected = match !~ / [.\)\]\}] /x || match =~ /\A\.\./
+              method_call_expected = self[1]
+              if inline_block_stack
+                case match
+                when '{'
+                  inline_block_curly_depth += 1
+                when '}'
+                  inline_block_curly_depth -= 1
+                  if inline_block_curly_depth == 0  # closing brace of inline block reached
+                    state, inline_block_curly_depth, heredocs = inline_block_stack.pop
+                    inline_block_stack = nil if inline_block_stack.empty?
+                    heredocs = nil if heredocs && heredocs.empty?
+                    encoder.text_token match, :inline_delimiter
+                    encoder.end_group :inline
+                    next
+                  end
+                end
+              end
+              encoder.text_token match, :operator
+
+            elsif match = scan(/ ['"] /mx)
+              encoder.begin_group :string
+              encoder.text_token match, :delimiter
+              state = patterns::StringState.new :string, match == '"', match  # important for streaming
+
+            elsif match = scan(unicode ? /#{patterns::INSTANCE_VARIABLE}/uo :
+                                         /#{patterns::INSTANCE_VARIABLE}/o)
+              value_expected = false
+              encoder.text_token match, :instance_variable
+
+            elsif value_expected and match?(/\//)
+              encoder.begin_group :regexp
+              if match?(/\/#{patterns::REGEXP_MODIFIERS}x#{patterns::REGEXP_MODIFIERS}[ \t]*(?:\n|#|\z|[,\)\]])/o)
+                # most likely a false positive, the end of an extended regexp
+                # so ignore this one and pretend we're inside the regexp
+              else
+                encoder.text_token getch, :delimiter
+              end
+              interpreted = true
+              state = patterns::StringState.new :regexp, interpreted, '/'
+
+            elsif match = scan(value_expected ? /[-+]?#{patterns::NUMERIC}/o : /#{patterns::NUMERIC}/o)
+              if method_call_expected
+                encoder.text_token match, :error
+                method_call_expected = false
+              else
+                encoder.text_token match, self[1] ? :float : :integer
+              end
+              value_expected = false
+
+            elsif match = scan(unicode ? /#{patterns::SYMBOL}/uo :
+                                         /#{patterns::SYMBOL}/o)
+              case delim = match[1]
+              when ?', ?"
+                encoder.begin_group :symbol
+                encoder.text_token ':', :symbol
+                match = delim.chr
+                encoder.text_token match, :delimiter
+                state = patterns::StringState.new :symbol, delim == ?", match
+              else
+                encoder.text_token match, :symbol
+                value_expected = false
+              end
+
+            elsif match = scan(/ [-+!~^]=? | [*|&]{1,2}=? | >>? /x)
+              value_expected = true
+              encoder.text_token match, :operator
+
+            elsif value_expected and match = scan(/#{patterns::HEREDOC_OPEN}/o)
+              indented = self[1] == '-'
+              quote = self[3]
+              delim = self[quote ? 4 : 2]
+              kind = patterns::QUOTE_TO_TYPE[quote]
+              encoder.begin_group kind
+              encoder.text_token match, :delimiter
+              encoder.end_group kind
+              heredoc = patterns::StringState.new kind, quote != '\'',
+                delim, (indented ? :indented : :linestart )
+              heredocs ||= []  # create heredocs if empty
+              heredocs << heredoc
+              value_expected = false
+
+            elsif value_expected and match = scan(/#{patterns::FANCY_START}/o)
+              kind, interpreted = *patterns::FancyStringType.fetch(self[1]) do
+                raise_inspect 'Unknown fancy string: %%%p' % k, encoder
+              end
+              encoder.begin_group kind
+              state = patterns::StringState.new kind, interpreted, self[2]
+              encoder.text_token match, :delimiter
+
+            elsif value_expected and match = scan(/#{patterns::CHARACTER}/o)
+              value_expected = false
+              encoder.text_token match, :integer
+
+            elsif match = scan(/ [\/%]=? | <(?:<|=>?)? | [?:;] /x)
+              value_expected = true
+              encoder.text_token match, :operator
+
+            elsif match = scan(/`/)
+              if method_call_expected
+                encoder.text_token match, :operator
+                value_expected = true
+              else
+                encoder.begin_group :shell
+                encoder.text_token match, :delimiter
+                state = patterns::StringState.new :shell, true, match
+              end
+
+            elsif match = scan(unicode ? /#{patterns::GLOBAL_VARIABLE}/uo :
+                                         /#{patterns::GLOBAL_VARIABLE}/o)
+              encoder.text_token match, :global_variable
+              value_expected = false
+
+            elsif match = scan(unicode ? /#{patterns::CLASS_VARIABLE}/uo :
+                                         /#{patterns::CLASS_VARIABLE}/o)
+              encoder.text_token match, :class_variable
+              value_expected = false
+
+            elsif match = scan(/\\\z/)
+              encoder.text_token match, :space
+
+            else
+              if method_call_expected
+                method_call_expected = false
+                next
+              end
+              if !unicode
+                # check for unicode
+                debug, $DEBUG = $DEBUG, false
+                begin
+                  if check(/./mu).size > 1
+                    # seems like we should try again with unicode
+                    unicode = true
+                  end
+                rescue
+                  # bad unicode char; use getch
+                ensure
+                  $DEBUG = debug
+                end
+                next if unicode
+              end
+              
+              encoder.text_token getch, :error
+              
+            end
+            
+            if last_state
+              state = last_state
+              last_state = nil
+            end
+
+          elsif state == :def_expected
+            if match = scan(unicode ? /(?>#{patterns::METHOD_NAME_EX})(?!\.|::)/uo :
+                                      /(?>#{patterns::METHOD_NAME_EX})(?!\.|::)/o)
+              encoder.text_token match, :method
+              state = :initial
+            else
+              last_state = :dot_expected
+              state = :initial
+            end
+
+          elsif state == :dot_expected
+            if match = scan(/\.|::/)
+              # invalid definition
+              state = :def_expected
+              encoder.text_token match, :operator
+            else
+              state = :initial
+            end
+
+          elsif state == :module_expected
+            if match = scan(/<</)
+              encoder.text_token match, :operator
+            else
+              state = :initial
+              if match = scan(unicode ? / (?:#{patterns::IDENT}::)* #{patterns::IDENT} /oux :
+                                        / (?:#{patterns::IDENT}::)* #{patterns::IDENT} /ox)
+                encoder.text_token match, :class
+              end
+            end
+
+          elsif state == :undef_expected
+            state = :undef_comma_expected
+            if match = scan(unicode ? /(?>#{patterns::METHOD_NAME_EX})(?!\.|::)/uo :
+                                      /(?>#{patterns::METHOD_NAME_EX})(?!\.|::)/o)
+              encoder.text_token match, :method
+            elsif match = scan(/#{patterns::SYMBOL}/o)
+              case delim = match[1]
+              when ?', ?"
+                encoder.begin_group :symbol
+                encoder.text_token ':', :symbol
+                match = delim.chr
+                encoder.text_token match, :delimiter
+                state = patterns::StringState.new :symbol, delim == ?", match
+                state.next_state = :undef_comma_expected
+              else
+                encoder.text_token match, :symbol
+              end
+            else
+              state = :initial
+            end
+
+          elsif state == :undef_comma_expected
+            if match = scan(/,/)
+              encoder.text_token match, :operator
+              state = :undef_expected
+            else
+              state = :initial
+            end
+
+          elsif state == :alias_expected
+            match = scan(unicode ? /(#{patterns::METHOD_NAME_OR_SYMBOL})([ \t]+)(#{patterns::METHOD_NAME_OR_SYMBOL})/uo :
+                                   /(#{patterns::METHOD_NAME_OR_SYMBOL})([ \t]+)(#{patterns::METHOD_NAME_OR_SYMBOL})/o)
+            
+            if match
+              encoder.text_token self[1], (self[1][0] == ?: ? :symbol : :method)
+              encoder.text_token self[2], :space
+              encoder.text_token self[3], (self[3][0] == ?: ? :symbol : :method)
+            end
+            state = :initial
+
+          else
+            raise_inspect 'Unknown state: %p' % [state], encoder
+          end
+          
+        end
+      end
+
+      # cleaning up
+      if options[:keep_state]
+        @state = state
+      end
+      if state.is_a? patterns::StringState
+        encoder.end_group state.type
+      end
+      if inline_block_stack
+        until inline_block_stack.empty?
+          state, *more = inline_block_stack.pop
+          encoder.end_group :inline if more
+          encoder.end_group state.type
+        end
+      end
+
+      encoder
+    end
+
+  end
+
+end
+end