Document Language class

lib/linguist/language.rb

@@ -8,100 +8,258 @@ module Linguist
     @lexer_index     = {}
     @extension_index = {}
 
+    # Internal: Create a new Language object
+    #
+    # attributes - A hash of attributes
+    #
+    # Returns a Language object
     def self.create(attributes = {})
       language = new(attributes)
 
+      # All Language names should be unique. Warn if there is a duplicate.
       if @name_index.key?(language.name.downcase)
         warn "Duplicate language name: #{language.name}"
       end
 
+      # Case-insensitive language name index
       @name_index[language.name.downcase] = language
 
+      # Set langauge as the default for reverse lexer lookup if
+      # :default_lexer is set or the language is the same name as its
+      # lexer.
       if attributes[:default_lexer] || language.default_lexer?
         @lexer_index[language.lexer_name.downcase] = language
       end
 
+      # Case-insensitive lexer name index
       @lexer_index[language.lexer_name.downcase] ||= language
 
       language.extensions.each do |extension|
+        # All Language extensions should be unique. Warn if there is a
+        # duplicate.
         if @extension_index.key?(extension)
           warn "Duplicate extension: #{extension}"
         end
 
+        # Index the extension with a leading ".": ".rb"
         @extension_index[extension] = language
+
+        # Index the extension without a leading ".": "rb"
         @extension_index[extension.sub(/^./, '')] = language
       end
 
       language
     end
 
-    def self.[](name)
-      find_by_name(name) || find_by_lexer(name)
-    end
-
+    # Public: Look up Language by its proper name.
+    #
+    # name - The case-insensitive String name of the Language
+    #
+    # Examples
+    #
+    #   Language.find_by_name('Ruby')
+    #   # => #<Language name="Ruby">
+    #
+    # Returns the Language or nil if none was found.
     def self.find_by_name(name)
       @name_index[name.downcase]
     end
 
+    # Public: Look up Language by extension.
+    #
+    # extension - The extension String. May include leading "."
+    #
+    # Examples
+    #
+    #   Language.find_by_extension('.rb')
+    #   # => #<Language name="Ruby">
+    #
+    # Returns the Language or nil if none was found.
     def self.find_by_extension(extension)
       @extension_index[extension]
     end
 
+    # Deprecated: Look up Language by its lexer.
+    #
+    # The use of this method is discouraged since multiple languages
+    # may have the same lexer name.
+    #
+    # name - The case-insensitive String lexer of the Language
+    #
+    # Examples
+    #
+    #   Language.find_by_lexer('cpp')
+    #   # => #<Language name="C++">
+    #
+    # Returns the Language or Language['Text'] if none was found.
     def self.find_by_lexer(lexer)
       @lexer_index[lexer.downcase] || self['Text']
     end
 
+    # Public: Look up Language by its name or lexer.
+    #
+    # name - The case-insensitive String name of the Language
+    #
+    # Examples
+    #
+    #   Language['Ruby']
+    #   # => #<Language name="Ruby">
+    #
+    #   Language['ruby']
+    #   # => #<Language name="Ruby">
+    #
+    # Returns the Language or nil if none was found.
+    def self.[](name)
+      find_by_name(name) || find_by_lexer(name)
+    end
+
+    # Public: A List of popular languages
+    #
+    # Popular languages are sorted to the top of language chooser
+    # dropdowns.
+    #
+    # This list is configured in "popular.yml".
+    #
+    # Returns an Array of Lexers.
     def self.popular
-      @name_index.values.select(&:popular?).sort_by { |lang| lang.name.downcase }
+      @popular ||= @name_index.values.select(&:popular?).sort_by { |lang| lang.name.downcase }
     end
 
+    # Public: A List of non-popular languages
+    #
+    # Unpopular languages appear below popular ones in language
+    # chooser dropdowns.
+    #
+    # This list is created from all the languages not listed in "popular.yml".
+    #
+    # Returns an Array of Lexers.
     def self.unpopular
-      @name_index.values.select(&:unpopular?).sort_by { |lang| lang.name.downcase }
+      @unpopular ||= @name_index.values.select(&:unpopular?).sort_by { |lang| lang.name.downcase }
     end
 
+    # Internal: Initialize a new Language
+    #
+    # attributes - A hash of attributes
     def initialize(attributes = {})
-      @name       = attributes[:name] || raise(ArgumentError, "missing name")
+      # @name is required
+      @name = attributes[:name] || raise(ArgumentError, "missing name")
+
+      # Use :lexer_name or fallback to `@name.downcase`
       @lexer_name = attributes[:lexer_name] || default_lexer_name
-      @lexer      = Lexer.find_by_alias(@lexer_name)
+
+      # Lookup Lexer object
+      @lexer = Lexer.find_by_alias(@lexer_name)
+
+      # Set extensions or default to [].
+      # Consider using `@lexer.extensions`
       @extensions = attributes[:extensions] || []
-      @popular    = attributes[:popular] || false
-      @common     = attributes[:common] || false
+
+      # Set popular or common flags
+      @popular = attributes[:popular] || false
+      @common  = attributes[:common] || false
     end
 
-    attr_reader :name, :lexer_name, :lexer, :extensions
+    # Public: Get proper name
+    #
+    # Examples
+    #
+    #   # => "Ruby"
+    #   # => "Python"
+    #   # => "Perl"
+    #
+    # Returns the name String
+    attr_reader :name
 
+    # Deprecated: Get lexer name
+    #
+    # Examples
+    #
+    #   # => "ruby"
+    #   # => "python"
+    #   # => "perl"
+    #
+    # Returns the name String
+    attr_reader :lexer_name
+
+    # Public: Get Lexer
+    #
+    # Returns the Lexer
+    attr_reader :lexer
+
+    # Public: Get extensions
+    #
+    # Examples
+    #
+    #   # => ['.rb', '.rake', 'Rakefile', ...]
+    #
+    # Returns the extensions Array
+    attr_reader :extensions
+
+    # Internal: Get default lexer name
+    #
+    # Returns the lexer name String
     def default_lexer_name
       name.downcase.gsub(/\s/, '-')
     end
 
+    # Internal: Is the language using the default lexer
+    #
+    # Returns true or false
     def default_lexer?
       lexer_name == default_lexer_name
     end
 
+    # Public: Get name for code search
+    #
+    # For historical reasons, code search uses a lower case form of
+    # the language name rather than the proper casing.
+    #
+    # Returns lexer String
     def search_term
       lexer_name
     end
 
+    # Public: Is it popular?
+    #
+    # Returns true or false
     def popular?
       @popular
     end
 
+    # Public: Is it not popular?
+    #
+    # Returns true or false
     def unpopular?
       !popular?
     end
 
+    # Public: Is it common?
+    #
+    # Returns true or false
     def common?
       @common
     end
 
+    # Public: Highlight syntax of text
+    #
+    # text - String of code to be highlighted
+    #
+    # Returns html String
     def colorize(text)
       lexer.colorize(text)
     end
 
+    # Public: Highlight syntax of text without the outer highlight div
+    # wrapper.
+    #
+    # text - String of code to be highlighted
+    #
+    # Returns html String
     def colorize_without_wrapper(text)
       lexer.colorize_without_wrapper(text)
     end
 
+    # Public: Return name as String representation
     def to_s
       name
     end

lib/linguist/popular.yml

@@ -1,25 +1,27 @@
+# Popular languages appear at the top of language dropdowns
+
 - ActionScript
 - Bash
 - C
-- Common Lisp
 - C#
 - C++
 - CSS
+- Common Lisp
 - Diff
 - Emacs Lisp
 - Erlang
-- Haskell
 - HTML
+- Haskell
 - Java
 - JavaScript
 - Lua
 - Objective-C
-- Perl
 - PHP
+- Perl
 - Python
 - Ruby
+- SQL
 - Scala
 - Scheme
-- SQL
 - TeX
 - XML