TUTORIAL: separating key classes from data types classes

tutorial/TOML/iter_1/toml_key.rb

@@ -4,19 +4,34 @@
 # An instance acts merely as a wrapper around a Ruby representation
 # of the key value.
 class TOMLKey
+ # Constructor. Initialize a TOML value from one of its built-in data type.
+ # @param _lexeme [String] Text representation of data type in TOML.
+ # @param _format [Symbol, NilClass] A symbolic name of the input format.
+ def initialize(_lexeme, _format = nil)
+ # Do nothing
+ end
+
  # @return [String] the literal key
  def key
  to_key
  end
- 
+
  # Method called from TOML to obtain the text representation of the boolean.
  # @return [String]
  def to_str
  key.to_s # Default implementation...
- end 
-
+ end
+
+ def ==(other)
+ return true if equal?(other)
+
+ return to_str == other if other.kind_of?(String)
+
+ key == other.key
+ end
+
  protected
- 
+
  def to_key
  raise NotImplementedError, 'Method to implement in subclass(es)'
  end
@@ -25,16 +40,25 @@ def to_key
 # Class implementing the TOML unquoted key data type.
 class UnquotedKey < TOMLKey
  # Constructor. Initialize an unquoted ket from the lexeme
- def initialize(aLexeme)
+ def initialize(aLexeme, format = nil)
+ super(aLexeme, format)
  @key = validated_key(aLexeme)
  end
 
+ alias value key
+
+ # Part of the 'visitee' role in Visitor design pattern.
+ # @param visitor [TOMLASTVisitor] the visitor
+ def accept(visitor)
+ visitor.visit_unquoted_key(self)
+ end
+
  protected
 
  def validated_key(aLexeme)
  aLexeme
  end
- 
+
  def to_key
  @key
  end

tutorial/TOML/iter_1/toml_tokenizer.rb

@@ -30,7 +30,7 @@ class TOMLTokenizer
  attr_reader(:line_start)
 
  # Mapping special character tokens to symbolic names
- # @return [{Char => String}] 
+ # @return [{Char => String}]
  Lexeme2name = {
  '=' => 'EQUAL'
  }.freeze

tutorial/TOML/iter_2/toml_datatype.rb

@@ -88,7 +88,7 @@ def validated_value(text, _format)
  compacted.to_f
  end
 end # class
-
+=begin
 # Class implementing the TOML unquoted key data type.
 class UnquotedKey < TOMLDatatype
  # Method to obtain the text representation of the object.
@@ -113,7 +113,7 @@ def validated_value(aValue, _format)
  aValue
  end
 end # class
-
+=end
 # Class implementing the TOML string data type.
 class TOMLString < TOMLDatatype
  PATT_STRING_ESCAPE = /\\(?:[^Uu]|u[0-9A-Fa-f]{0,4}|U[0-9A-Fa-f]{0,8})/.freeze

tutorial/TOML/iter_2/toml_key.rb

@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+require_relative '../iter_1/toml_key'

tutorial/TOML/iter_2/toml_tokenizer.rb

@@ -3,6 +3,7 @@
 require 'strscan'
 require 'rley'
 require_relative 'toml_datatype'
+require_relative 'toml_key'
 
 # A tokenizer for a very limited subset of TOML.
 # Responsibilities:
@@ -50,7 +51,7 @@ class TOMLTokenizer
  attr_reader(:line_start)
 
  # Mapping special character tokens to symbolic names
- # @return [{Char => String}] 
+ # @return [{Char => String}]
  Lexeme2name = {
  ',' => 'COMMA',
  '=' => 'EQUAL',

tutorial/TOML/iter_3/toml_datatype.rb

@@ -5,10 +5,6 @@
 require 'date'
 require 'forwardable'
 
-# Class implementing the TOML unquoted key data type.
-class QuotedKey < TOMLString
-end # class
-
 # Class implementing the TOML offset date-time data type.
 class TOMLOffsetDateTime < TOMLDatatype
  extend Forwardable

tutorial/TOML/iter_3/toml_key.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require_relative '../iter_2/toml_key'
+require_relative 'toml_datatype'
+
+# Class implementing the TOML quoted key data type.
+class QuotedKey < TOMLKey
+ extend Forwardable
+ def_delegators :@key, :value
+
+ def initialize(aLexeme, aFormat)
+ super(aLexeme, aFormat)
+ @key = TOMLString.new(aLexeme, aFormat)
+ end
+
+ # Part of the 'visitee' role in Visitor design pattern.
+ # @param visitor [TOMLASTVisitor] the visitor
+ def accept(visitor)
+ visitor.visit_unquoted_key(self)
+ end
+
+ protected
+
+ def to_key
+ @key.value
+ end
+end # class

tutorial/TOML/iter_3/toml_tokenizer.rb

@@ -3,6 +3,7 @@
 require 'strscan'
 require 'rley'
 require_relative 'toml_datatype'
+require_relative 'toml_key'
 
 # A tokenizer for a very limited subset of TOML.
 # Responsibilities: