method

init_separators

v1_9_1_378 - Show latest stable - 0 notes - Class: CSV

init_separators(options) private

Stores the indicated separators for later use.

If auto-discovery was requested for @row_sep, this method will read ahead in the @io and try to find one. ARGF, STDIN, STDOUT, STDERR and any stream open for output only with a default @row_sep of $INPUT_RECORD_SEPARATOR ($/).

This method also establishes the quoting rules used for CSV output.

Show source

# File lib/csv.rb, line 1951
  def init_separators(options)
    # store the selected separators
    @col_sep    = options.delete(:col_sep).to_s.encode(@encoding)
    @row_sep    = options.delete(:row_sep)  # encode after resolving :auto
    @quote_char = options.delete(:quote_char).to_s.encode(@encoding)

    if @quote_char.length != 1
      raise ArgumentError, ":quote_char has to be a single character String"
    end
    
    # 
    # automatically discover row separator when requested
    # (not fully encoding safe)
    # 
    if @row_sep == :auto
      if [ARGF, STDIN, STDOUT, STDERR].include?(@io) or
         (defined?(Zlib) and @io.class == Zlib::GzipWriter)
        @row_sep = $INPUT_RECORD_SEPARATOR
      else
        begin
          saved_pos = @io.pos  # remember where we were
          while @row_sep == :auto
            # 
            # if we run out of data, it's probably a single line 
            # (use a sensible default)
            # 
            if @io.eof?
              @row_sep = $INPUT_RECORD_SEPARATOR
              break
            end
      
            # read ahead a bit
            sample =  read_to_char(1024)
            sample += read_to_char(1) if sample[-1..-1] == encode_str("\r") and
                                         not @io.eof?
            # try to find a standard separator
            if sample =~ encode_re("\r\n?|\n")
              @row_sep = $&
              break
            end
          end
          # tricky seek() clone to work around GzipReader's lack of seek()
          @io.rewind
          # reset back to the remembered position
          while saved_pos > 1024  # avoid loading a lot of data into memory
            @io.read(1024)
            saved_pos -= 1024
          end
          @io.read(saved_pos) if saved_pos.nonzero?
        rescue IOError  # stream not opened for reading
          @row_sep = $INPUT_RECORD_SEPARATOR
        end
      end
    end
    @row_sep = @row_sep.to_s.encode(@encoding)
    
    # establish quoting rules
    @force_quotes = options.delete(:force_quotes)
    do_quote      = lambda do |field|
      @quote_char                                      +
      String(field).gsub(@quote_char, @quote_char * 2) +
      @quote_char
    end
    quotable_chars = encode_str("\r\n", @col_sep, @quote_char)
    @quote         = if @force_quotes
      do_quote
    else
      lambda do |field|
        if field.nil?  # represent +nil+ fields as empty unquoted fields
          ""
        else
          field = String(field)  # Stringify fields
          # represent empty fields as empty quoted fields
          if field.empty? or
             field.count(quotable_chars).nonzero?
            do_quote.call(field)
          else
            field  # unquoted field
          end
        end
      end
    end
  end

init_separators

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