Class: KDL::V1::Tokenizer

Inherits:
Tokenizer show all
Defined in:
lib/kdl/v1/tokenizer.rb

Constant Summary collapse

NON_IDENTIFIER_CHARS = 
Regexp.escape "#{SYMBOLS.keys.join}()/\\<>[]\",#{WHITESPACE.join}#{OTHER_NON_IDENTIFIER_CHARS.join}"
IDENTIFIER_CHARS = 
/[^#{NON_IDENTIFIER_CHARS}]/
INITIAL_IDENTIFIER_CHARS = 
/[^#{NON_IDENTIFIER_CHARS}0-9]/

Constants inherited from Tokenizer

Tokenizer::FORBIDDEN, Tokenizer::NEWLINES, Tokenizer::NEWLINES_PATTERN, Tokenizer::OTHER_NON_IDENTIFIER_CHARS, Tokenizer::SYMBOLS, Tokenizer::VERSION_PATTERN, Tokenizer::WHITESPACE, Tokenizer::WS, Tokenizer::WS_PLUS, Tokenizer::WS_STAR

Instance Attribute Summary

Attributes inherited from Tokenizer

#filename, #index

Instance Method Summary collapse

Methods inherited from Tokenizer

#[], #done?, #initialize, #tokens, #version_directive

Constructor Details

This class inherits a constructor from KDL::Tokenizer

Instance Method Details

#next_token ⇒ Object 



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# File 'lib/kdl/v1/tokenizer.rb', line 10

def next_token
  @context = nil
  @previous_context = nil
  @line_at_start = @line
  @column_at_start = @column
  loop do
    c = self[@index]
    case @context
    when nil
      case c
      when '"'
        self.context = :string
        @buffer = +''
        traverse(1)
      when 'r'
        if @str[@index + 1] == '"'
          self.context = :rawstring
          traverse(2)
          @rawstring_hashes = 0
          @buffer = +''
          next
        elsif @str[@index + 1] == '#'
          i = @index + 1
          @rawstring_hashes = 0
          while @str[i] == '#'
            @rawstring_hashes += 1
            i += 1
          end
          if @str[i] == '"'
            self.context = :rawstring
            @index = i + 1
            @buffer = +''
            next
          end
        end
        self.context = :ident
        @buffer = +c
        traverse(1)
      when '-'
        n = self[@index + 1]
        if n =~ /[0-9]/
          n2 = self[@index + 2]
          if n == '0' && n2 =~ /[box]/
            self.context = integer_context(n2)
            traverse(3)
          else
            self.context = :decimal
            traverse(1)
          end
        else
          self.context = :ident
          traverse(1)
        end
        @buffer = +c
      when /[0-9+]/
        n = self[@index + 1]
        if c == '0' && n =~ /[box]/
          traverse(2)
          @buffer = +''
          self.context = integer_context(n)
        else
          self.context = :decimal
          @buffer = +c
          traverse(1)
        end
      when '\\'
        t = Tokenizer.new(@str, @index + 1)
        la = t.next_token
        if la[0] == :NEWLINE || la[0] == :EOF || (la[0] == :WS && (lan = t.next_token[0]) == :NEWLINE || lan == :EOF)
          traverse_to(t.index)
          @buffer = "#{c}#{la[1].value}"
          @buffer << "\n" if lan == :NEWLINE
          self.context = :whitespace
        else
          raise_error "Unexpected '\\' (#{la[0]})"
        end
      when *SYMBOLS.keys
        return token(SYMBOLS[c], -c).tap { traverse(1) }
      when *NEWLINES, "\r"
        nl = expect_newline
        return token(:NEWLINE, -nl).tap do
          traverse(nl.length)
        end
      when "/"
        if self[@index + 1] == '/'
          self.context = :single_line_comment
          traverse(2)
        elsif self[@index + 1] == '*'
          self.context = :multi_line_comment
          @comment_nesting = 1
          traverse(2)
        elsif self[@index + 1] == '-'
          return token(:SLASHDASH, '/-').tap { traverse(2) }
        else
          self.context = :ident
          @buffer = +c
          traverse(1)
        end
      when *WHITESPACE
        self.context = :whitespace
        @buffer = +c
        traverse(1)
      when nil
        return [false, token(:EOF, :EOF)[1]] if @done

        @done = true
        return token(:EOF, :EOF)
      when INITIAL_IDENTIFIER_CHARS
        self.context = :ident
        @buffer = +c
        traverse(1)
      when '('
        @type_context = true
        return token(:LPAREN, -c).tap { traverse(1) }
      when ')'
        @type_context = false
        return token(:RPAREN, -c).tap { traverse(1) }
      else
        raise_error "Unexpected character #{c.inspect}"
      end
    when :ident
      case c
      when IDENTIFIER_CHARS
        traverse(1)
        @buffer << c
      else
        case @buffer
        when 'true'  then return token(:TRUE, true)
        when 'false' then return token(:FALSE, false)
        when 'null'  then return token(:NULL, nil)
        else return token(:IDENT, -@buffer)
        end
      end
    when :string
      case c
      when '\\'
        c2 = self[@index + 1]
        if c2.match?(NEWLINES_PATTERN)
          i = 2
          while self[@index + i].match?(NEWLINES_PATTERN)
            i+=1
          end
          traverse(i)
        else
          @buffer << c
          @buffer << c2
          traverse(2)
        end
      when '"'
        return token(:STRING, -unescape(@buffer)).tap { traverse(1) }
      when nil
        raise_error "Unterminated string literal"
      else
        @buffer << c
        traverse(1)
      end
    when :rawstring
      raise_error "Unterminated rawstring literal" if c.nil?

      if c == '"'
        h = 0
        h += 1 while self[@index + 1 + h] == '#' && h < @rawstring_hashes
        if h == @rawstring_hashes
          return token(:RAWSTRING, -@buffer).tap { traverse(1 + h) }
        end
      end

      @buffer << c
      traverse(1)
    when :decimal
      case c
      when /[0-9.\-+_eE]/
        traverse(1)
        @buffer << c
      else
        return parse_decimal(@buffer)
      end
    when :hexadecimal
      case c
      when /[0-9a-fA-F_]/
        traverse(1)
        @buffer << c
      else
        return parse_hexadecimal(@buffer)
      end
    when :octal
      case c
      when /[0-7_]/
        traverse(1)
        @buffer << c
      else
        return parse_octal(@buffer)
      end
    when :binary
      case c
      when /[01_]/
        traverse(1)
        @buffer << c
      else
        return parse_binary(@buffer)
      end
    when :single_line_comment
      case c
      when *NEWLINES, "\r"
        self.context = nil
        @column_at_start = @column
        next
      when nil
        @done = true
        return token(:EOF, :EOF)
      else
        traverse(1)
      end
    when :multi_line_comment
      if c == '/' && self[@index + 1] == '*'
        @comment_nesting += 1
        traverse(2)
      elsif c == '*' && self[@index + 1] == '/'
        @comment_nesting -= 1
        traverse(2)
        if @comment_nesting == 0
          revert_context
        end
      else
        traverse(1)
      end
    when :whitespace
      if WHITESPACE.include?(c)
        traverse(1)
        @buffer << c
      elsif c == "/" && self[@index + 1] == '*'
        self.context = :multi_line_comment
        @comment_nesting = 1
        traverse(2)
      elsif c == "\\"
        t = Tokenizer.new(@str, @index + 1)
        la = t.next_token
        if la[0] == :NEWLINE || la[0] == :EOF || (la[0] == :WS && (lan = t.next_token[0]) == :NEWLINE || lan == :EOF)
          traverse_to(t.index)
          @buffer << "#{c}#{la[1].value}"
          @buffer << "\n" if lan == :NEWLINE
        else
          raise_error "Unexpected '\\' (#{la[0]})"
        end
      else
        return token(:WS, -@buffer)
      end
    else
      # :nocov:
      raise_error "Unknown context `#{@context}'"
      # :nocov:
    end
  end
end