Class: HCLLexer

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

Defined Under Namespace

Classes: ScanError

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#filename ⇒ Object (readonly)

Returns the value of attribute filename.



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# File 'lib/hcl/lexer.rb', line 14

def filename
  @filename
end

#lineno ⇒ Object (readonly)

Returns the value of attribute lineno.



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# File 'lib/hcl/lexer.rb', line 13

def lineno
  @lineno
end

#state ⇒ Object

Returns the value of attribute state.



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# File 'lib/hcl/lexer.rb', line 15

def state
  @state
end

Instance Method Details

#_next_token ⇒ Object 



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# File 'lib/hcl/lexer.rb', line 54

def _next_token
  text = @ss.peek(1)
  @lineno  +=  1  if text == "\n"
  token = case @state
  when nil
    case
    when (text = @ss.scan(/\s+/))
      ;

    when (text = @ss.scan(/\#.*|\/\/.*$/))
      ;

    when (text = @ss.scan(/\n|\r/))
      ;

    when (text = @ss.scan(/\/\*/))
       action { consume_comment(text) }

    when (text = @ss.scan(/true|false/))
       action { [:BOOL,         to_boolean(text)]}

    when (text = @ss.scan(/-?\d+/))
       action { [:NUMBER,       text.to_i] }

    when (text = @ss.scan(/\-?\d+\.\d+/))
       action { [:FLOAT,        text.to_f] }

    when (text = @ss.scan(/\"/))
       action { [:STRING,       consume_string(text)] }

    when (text = @ss.scan(/\{/))
       action { [:LEFTBRACE,    text]}

    when (text = @ss.scan(/\}/))
       action { [:RIGHTBRACE,   text]}

    when (text = @ss.scan(/\[/))
       action { [:LEFTBRACKET,  text]}

    when (text = @ss.scan(/\]/))
       action { [:RIGHTBRACKET, text]}

    when (text = @ss.scan(/\,/))
       action { [:COMMA,        text]}

    when (text = @ss.scan(/[a-zA-Z_][a-zA-Z0-9_\-\.]*/))
       action { [:IDENTIFIER,   text]}

    when (text = @ss.scan(/\=/))
       action { [:EQUAL,        text]}

    when (text = @ss.scan(/\-/))
       action { [:MINUS,        text]}

    else
      text = @ss.string[@ss.pos .. -1]
      raise  ScanError, "can not match: '" + text + "'"
    end  # if

  else
    raise  ScanError, "undefined state: '" + state.to_s + "'"
  end  # case state
  token
end

#action ⇒ Object 



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# File 'lib/hcl/lexer.rb', line 23

def action
  yield
end

#consume_comment(input) ⇒ Object 



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# File 'lib/hcl/lexer.rb', line 136

def consume_comment(input)
  nested = 1
  until nested.zero?
    case(text = @ss.scan_until(%r{/\*|\*/|\z}) )
    when %r{/\*\z}
      nested =+ 1
    when %r{\*/\z}
      nested -= 1
    else
      break
    end
  end
end

#consume_string(input) ⇒ Object 



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# File 'lib/hcl/lexer.rb', line 149

def consume_string(input)
  result = ''
  nested = 0
  begin
    case(text = @ss.scan_until(%r{\"|\$\{|\}|\\}))
    when %r{\$\{\z}
      nested += 1
    when %r{\}\z}
      nested -= 1
    when %r{\\\z}
      result += text.chop + @ss.getch
      next
    end
    result += text.to_s
  end until nested == 0 && text =~ %r{\"\z}
  result.chop
end

#lex(input) ⇒ Object

def _next_token



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# File 'lib/hcl/lexer.rb', line 119

def lex(input)
  scan_setup(input)
  tokens = []
  while token = next_token
    tokens << token
  end
  tokens
end

#load_file(filename) ⇒ Object 



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# File 'lib/hcl/lexer.rb', line 33

def load_file( filename )
  @filename = filename
  open(filename, "r") do |f|
    scan_setup(f.read)
  end
end

#next_token ⇒ Object 



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# File 'lib/hcl/lexer.rb', line 46

def next_token
  return if @ss.eos?
  
  # skips empty actions
  until token = _next_token or @ss.eos?; end
  token
end

#scan_file(filename) ⇒ Object 



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# File 'lib/hcl/lexer.rb', line 40

def scan_file( filename )
  load_file(filename)
  do_parse
end

#scan_setup(str) ⇒ Object 



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# File 'lib/hcl/lexer.rb', line 17

def scan_setup(str)
  @ss = StringScanner.new(str)
  @lineno =  1
  @state  = nil
end

#scan_str(str) ⇒ Object Also known as: scan 



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# File 'lib/hcl/lexer.rb', line 27

def scan_str(str)
  scan_setup(str)
  do_parse
end

#to_boolean(input) ⇒ Object 



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# File 'lib/hcl/lexer.rb', line 127

def to_boolean(input)
  input =
    if input =~ /true/
      true
    elsif input =~ /false/
      false
    end
  return input
end