Class: GQL::Tokenizer

Inherits:
Racc::Parser
  • Object
show all
Defined in:
lib/gql/tokenizer.rb

Direct Known Subclasses

Parser

Defined Under Namespace

Classes: Unused

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/gql/tokenizer.rb', line 14

def filename
  @filename
end

#lineno ⇒ Object (readonly)

Returns the value of attribute lineno.



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# File 'lib/gql/tokenizer.rb', line 13

def lineno
  @lineno
end

#state ⇒ Object

Returns the value of attribute state.



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# File 'lib/gql/tokenizer.rb', line 15

def state
  @state
end

Instance Method Details

#_next_token ⇒ Object 



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# File 'lib/gql/tokenizer.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(/\/\*/))
       action { @state = :REMS; nil }

    when (text = @ss.scan(/\/\//))
       action { @state = :REM;  nil }

    when (text = @ss.scan(/"(?:[^"\\]|\\["\\\/bfnrt]|\\u[0-9a-fA-F]{4})*"/))
       action { [:STRING, convert_json(text)] }

    when (text = @ss.scan(/-?(?:0|[1-9]\d*)(?:\.\d+)?(?:[eE][+-]?\d+)?/))
       action { [:NUMBER, text] }

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

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

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

    when (text = @ss.scan(/[aA][sS]\b/))
       action { [:AS, text] }

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

    when (text = @ss.scan(/(?:[[:blank:]]|\f)+/))
      ;

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

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

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

  when :REMS
    case
    when (text = @ss.scan(/\*\//))
       action { @state = nil;   nil }

    when (text = @ss.scan(/.*(?=\*\/)/))
      ;

    when (text = @ss.scan(/.+(?=\n)/))
      ;

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

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

  when :REM
    case
    when (text = @ss.scan(/\n/))
       action { @state = nil;   nil }

    when (text = @ss.scan(/.*(?=$)/))
      ;

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

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

#action ⇒ Object 



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# File 'lib/gql/tokenizer.rb', line 23

def action
  yield
end

#load_file(filename) ⇒ Object 



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# File 'lib/gql/tokenizer.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/gql/tokenizer.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/gql/tokenizer.rb', line 40

def scan_file( filename )
  load_file(filename)
  do_parse
end

#scan_setup(str) ⇒ Object 



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# File 'lib/gql/tokenizer.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/gql/tokenizer.rb', line 27

def scan_str(str)
  scan_setup(str)
  do_parse
end