Class: Rutaci::Formater

Inherits:
Object
  • Object
show all
Defined in:
lib/rutaci/formater.rb

Constant Summary collapse

PLACEHOLDERS =

translation of format string tokens to info field names

{
  "t" => :title,
  "i" => :artist,
  "a" => :album,
  "n" => :track,
  "y" => :year,
  "g" => :genre,
  "c" => :comment
}

Class Method Summary collapse

Class Method Details

.string_for_token(token, info) ⇒ Object

def self.tokenize



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# File 'lib/rutaci/formater.rb', line 66

def self.string_for_token(token, info)
  placeholder = token[-1].chr # the placeholder is the last letter
  flags = token[0..-2] # the rest are flags
  value = info[PLACEHOLDERS[placeholder]]
  case value
  when Fixnum, Bignum
    value = sprintf "%#{flags}d", value
  when String
    value = sprintf "%#{flags}s", value
  else # for other classes no flags are defined (yet ;-)
    value = value.to_s
  end
  return value
end

.tokenize(format) ⇒ Object

performs a lexical analysis for strings like “%n - %t” and yields every token found. A token may be a normal char or a placeholder the argumetns passed to the block is the current token and if it’s a placeholder or not Note that a placeholder token is passed without the leading ‘%’ A placeholder token always ends with a lower case letter and may have some leading flags A flag is everything which isn’t a lower case letter or the ‘%’ sign

Raises:

  • (ArgumentError) 


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# File 'lib/rutaci/formater.rb', line 37

def self.tokenize(format)
  raise ArgumentError, "need a block to handle the tokens" unless block_given?
  is_placeholder = false # true if the previous char was a '%'
  multichar_token = "" # here the chars for multichar tokens are acculumated before the comleate token is send out
  format.each_byte do |c|
    if is_placeholder
      if c == ?%
        yield c.chr, false # '%%' is not the placeholder '%' but a normal '%'
      else
        # look out for multichar tokens
        multichar_token += c.chr
        if /[a-z]/.match multichar_token
          yield multichar_token, true
          multichar_token = ""
        else
          next
        end
      end
      is_placeholder = false
    else
      if c == ?%
        is_placeholder = true
      else
        yield c.chr, false
      end
    end # is_placeholder?
  end # each_byte
end