Class: Sequel::Postgres::PGArray::Parser

Inherits:
StringScanner
  • Object
show all
Defined in:
lib/sequel/extensions/pg_array.rb

Constant Summary

UNQUOTED_RE =
/[{}",]|[^{}",]+/
QUOTED_RE =
/["\\]|[^"\\]+/
NULL_RE =
/NULL",/
OPEN_RE =
/\{/

Instance Method Summary collapse

Constructor Details

#initialize(source, converter = nil) ⇒ Parser



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# File 'lib/sequel/extensions/pg_array.rb', line 343

def initialize(source, converter=nil)
  super(source)
  @converter = converter 
  @stack = [[]]
  @recorded = ""
end

Instance Method Details

#new_entry(include_empty = false) ⇒ Object



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# File 'lib/sequel/extensions/pg_array.rb', line 352

def new_entry(include_empty=false)
  if !@recorded.empty? || include_empty
    entry = @recorded
    if entry == NULL && !include_empty
      entry = nil
    elsif @converter
      entry = @converter.call(entry)
    end
    @stack.last.push(entry)
    @recorded = ""
  end
end

#parseObject

Raises:



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# File 'lib/sequel/extensions/pg_array.rb', line 367

def parse
  raise Sequel::Error, "invalid array, empty string" if eos?
  raise Sequel::Error, "invalid array, doesn't start with {" unless scan(OPEN_RE)

  while !eos?
    char = scan(UNQUOTED_RE)
    if char == COMMA
      # Comma outside quoted string indicates end of current entry
      new_entry
    elsif char == QUOTE
      raise Sequel::Error, "invalid array, opening quote with existing recorded data" unless @recorded.empty?
      while true
        char = scan(QUOTED_RE)
        if char == BACKSLASH
          @recorded << getch
        elsif char == QUOTE
          n = peek(1)
          raise Sequel::Error, "invalid array, closing quote not followed by comma or closing brace" unless n == COMMA || n == CLOSE_BRACE
          break
        else
          @recorded << char
        end
      end
      new_entry(true)
    elsif char == OPEN_BRACE
      raise Sequel::Error, "invalid array, opening brace with existing recorded data" unless @recorded.empty?

      # Start of new array, add it to the stack
      new = []
      @stack.last << new
      @stack << new
    elsif char == CLOSE_BRACE
      # End of current array, add current entry to the current array
      new_entry

      if @stack.length == 1
        raise Sequel::Error, "array parsing finished without parsing entire string" unless eos?

        # Top level of array, parsing should be over.
        # Pop current array off stack and return it as result
        return @stack.pop
      else
        # Nested array, pop current array off stack
        @stack.pop
      end
    else
      # Add the character to the recorded character buffer.
      @recorded << char
    end
  end

  raise Sequel::Error, "array parsing finished with array unclosed"
end