Class: DMark::Lexer

Inherits:
Object
  • Object
show all
Defined in:
lib/dmark/lexer.rb

Defined Under Namespace

Classes: LexerError

Constant Summary collapse

INDENTATION = 
2

Instance Method Summary collapse

Constructor Details

#initialize(string) ⇒ Lexer

Returns a new instance of Lexer.



5
6
7
8
9
10
11
 
# File 'lib/dmark/lexer.rb', line 5

def initialize(string)
  @string = string

  @element_stack = []
  @tokens = []
  @pending_blanks = 0
end

Instance Method Details

#run ⇒ Object 



13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
 
# File 'lib/dmark/lexer.rb', line 13

def run
  @string.lines.each_with_index do |line, line_nr|
    case line
    when /^\s+$/
      # blank line
      @pending_blanks += 1
    when /^(\s*)([a-z0-9-]+)(\[(.*?)\])?\.\s*$/
      # empty element
      indentation = Regexp.last_match[1]
      element = Regexp.last_match[2]
      attributes = parse_attributes(Regexp.last_match[4])

      unwind_stack_until(indentation.size)

      @element_stack << element
      @tokens << DMark::Tokens::TagBeginToken.new(name: element, attributes: attributes)
    when /^(\s*)([a-z0-9-]+)(\[(.*?)\])?\. (.*)$/
      # element with inline content
      indentation = Regexp.last_match[1]
      element = Regexp.last_match[2]
      attributes = parse_attributes(Regexp.last_match[4])
      data = Regexp.last_match[5]

      unwind_stack_until(indentation.size)

      @tokens << DMark::Tokens::TagBeginToken.new(name: element, attributes: attributes)
      @tokens.concat(lex_inline(data, line_nr + 1))
      @tokens << DMark::Tokens::TagEndToken.new(name: element)
    when /^(\s*)(.*)$/
      # other line (e.g. data)
      indentation = Regexp.last_match[1]
      data = Regexp.last_match[2]

      unwind_stack_until(indentation.size)

      if @element_stack.empty?
        # FIXME: unify format of messages (uppercase, lowercase, …)
        raise LexerError.new("Can’t insert raw data at root level", line, line_nr, 1)
      end

      extra_indentation = [indentation.size - INDENTATION * @element_stack.size, 0].max

      @tokens.concat(lex_inline(' ' * extra_indentation + data + "\n", line_nr + 1))
    end
  end

  unwind_stack_until(0)

  @tokens
end