From 6f5ce67f72e5ff1f76ae52129653cd3367b1e083 Mon Sep 17 00:00:00 2001
From: murphy <murphy@rubychan.de>
Date: Sat, 5 Nov 2005 02:57:21 +0000
Subject: scanner_helper.rb: more doc, re-indented

---
 lib/coderay/helpers/scanner_helper.rb | 162 +++++++++++++++++++++-------------
 1 file changed, 103 insertions(+), 59 deletions(-)

(limited to 'lib/coderay')

diff --git a/lib/coderay/helpers/scanner_helper.rb b/lib/coderay/helpers/scanner_helper.rb
index a2e14bb..9f48b83 100644
--- a/lib/coderay/helpers/scanner_helper.rb
+++ b/lib/coderay/helpers/scanner_helper.rb
@@ -1,63 +1,107 @@
 module CodeRay
-module Scanners
-
-  class Scanner
-
-    # A WordList is a Hash with some additional features.
-    # It is intended to be used for keyword recognition.
-    class WordList < Hash
-
-      def initialize default = false, case_mode = :case_match
-        @case_ignore =
-          case case_mode
-          when :case_match then false
-          when :case_ignore then true
-          else
-            raise ArgumentError,
-              "#{self.class.name}.new: second argument must be :case_ignore or :case_match, but #{case_mode} was given."
-          end
-
-        if @case_ignore
-          super() do |h, k|
-            h[k] = h.fetch k.downcase, default
-          end
-        else
-          super default
-        end
-      end
-
-      def include? word
-        self[word] if @case_ignore
-        has_key? word
-      end
-
-      def add words, kind = true
-        words.each do |word|
-          self[mind_case(word)] = kind
-        end
-        self
-      end
-
-      alias words keys
-
-      def case_ignore?
-        @case_mode
-      end
-
-    private
-      def mind_case word
-        if @case_ignore
-          word.downcase
-        else
-          word.dup
-        end
-      end
-
-    end		
-
-  end
+	module Scanners
 
-end
+		class Scanner
+
+			# A WordList is a Hash with some additional features.
+			# It is intended to be used for keyword recognition.
+			#
+			# WordList is highly optimized to be used in Scanners,
+			# typically to decide whether a given ident is a keyword.
+			#
+			# Example:
+			# 
+			#  # define word arrays
+			#  RESERVED_WORDS = %w[
+			#    asm break case continue default do else
+			#    ...		
+			#  ]
+			#  
+			#  PREDEFINED_TYPES = %w[
+			#    int long short char void
+			#    ...
+			#  ]
+			#  
+			#  PREDEFINED_CONSTANTS = %w[
+			#    EOF NULL ...
+			#  ]
+			#  
+			#  # make a WordList
+			#  IDENT_KIND = Scanner::WordList.new(:ident).
+			#    add(RESERVED_WORDS, :reserved).
+			#    add(PREDEFINED_TYPES, :pre_type).
+			#    add(PREDEFINED_CONSTANTS, :pre_constant)
+			#
+			#  ...
+			#
+			#  def scan_tokens tokens, options
+			#    ...
+			#    
+			#    elsif match = scan(/ [A-Za-z_][A-Za-z_0-9]* /x)
+			#      # use it
+			#      kind = IDENT_KIND[match]
+			#      ...
+			#  
+			class WordList < Hash
+
+				# Creates a new WordList with +default+ as default value.
+				# case_mode controls how keys are compared;
+				# :case_match is faster.
+				def initialize default = false, case_mode = :case_match
+					@case_ignore =
+						case case_mode
+						when :case_match then false
+						when :case_ignore then true
+						else raise ArgumentError,
+							":case_ignore or :case_match expected, but #{case_mode} given"
+						end
+
+					if @case_ignore
+						super() do |h, k|
+							h[k] = h.fetch k.downcase, default
+						end
+					else
+						super default
+					end
+				end
+
+				# Checks if a word is included.
+				def include? word
+					self[word] if @case_ignore
+					has_key? word
+				end
+
+				# Add words to the list and associate them with
+				# +kind+.
+				def add words, kind = true
+					words.each do |word|
+						self[mind_case(word)] = kind
+					end
+					self
+				end
+
+				alias words keys
+
+				# Returns whether key comparing is done case insensitive.
+				def case_ignore?
+					@case_mode
+				end
+
+			private
+				# helper method for key 
+				def mind_case word
+					if @case_ignore
+						word.downcase
+					else
+						word.dup
+					end
+				end
+
+			end		
+
+		end
+
+	end
 end
 
-# vim:sw=2:ts=2:et:tw=78
+# vim:sw=2:ts=2:noet:tw=78
-- 
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