class Sequel::Postgres::PGArray::Parser

  1. lib/sequel/extensions/pg_array.rb
Superclass: StringScanner

PostgreSQL array parser that handles PostgreSQL array output format. Note that does not handle all forms out input that PostgreSQL will accept, and it will not raise an error for all forms of invalid input.

Methods

Public Class

  1. new

Public Instance

  1. new_entry
  2. parse

Public Class methods

new(source, converter=nil)

Set the source for the input, and any converter callable to call with objects to be created. For nested parsers the source may contain text after the end current parse, which will be ignored.

[show source]
    # File lib/sequel/extensions/pg_array.rb
337 def initialize(source, converter=nil)
338   super(source)
339   @converter = converter 
340   @stack = [[]]
341   @encoding = string.encoding
342   @recorded = String.new.force_encoding(@encoding)
343 end

Public Instance methods

new_entry(include_empty=false)

Take the buffer of recorded characters and add it to the array of entries, and use a new buffer for recorded characters.

[show source]
    # File lib/sequel/extensions/pg_array.rb
347 def new_entry(include_empty=false)
348   if !@recorded.empty? || include_empty
349     entry = @recorded
350     if entry == 'NULL' && !include_empty
351       entry = nil
352     elsif @converter
353       entry = @converter.call(entry)
354     end
355     @stack.last.push(entry)
356     @recorded = String.new.force_encoding(@encoding)
357   end
358 end
parse()

Parse the input character by character, returning an array of parsed (and potentially converted) objects.

[show source]
    # File lib/sequel/extensions/pg_array.rb
362 def parse
363   raise Sequel::Error, "invalid array, empty string" if eos?
364   raise Sequel::Error, "invalid array, doesn't start with {" unless scan(/((\[\d+:\d+\])+=)?\{/)
365 
366   # simplecov:disable
367   while !eos?
368   # simplecov:enable
369     char = scan(/[{}",]|[^{}",]+/)
370     if char == ','
371       # Comma outside quoted string indicates end of current entry
372       new_entry
373     elsif char == '"'
374       raise Sequel::Error, "invalid array, opening quote with existing recorded data" unless @recorded.empty?
375       # simplecov:disable
376       while true
377       # simplecov:enable
378         char = scan(/["\\]|[^"\\]+/)
379         if char == '\\'
380           @recorded << getch
381         elsif char == '"'
382           n = peek(1)
383           raise Sequel::Error, "invalid array, closing quote not followed by comma or closing brace" unless n == ',' || n == '}'
384           break
385         else
386           @recorded << char
387         end
388       end
389       new_entry(true)
390     elsif char == '{'
391       raise Sequel::Error, "invalid array, opening brace with existing recorded data" unless @recorded.empty?
392 
393       # Start of new array, add it to the stack
394       new = []
395       @stack.last << new
396       @stack << new
397     elsif char == '}'
398       # End of current array, add current entry to the current array
399       new_entry
400 
401       if @stack.length == 1
402         raise Sequel::Error, "array parsing finished without parsing entire string" unless eos?
403 
404         # Top level of array, parsing should be over.
405         # Pop current array off stack and return it as result
406         return @stack.pop
407       else
408         # Nested array, pop current array off stack
409         @stack.pop
410       end
411     else
412       # Add the character to the recorded character buffer.
413       @recorded << char
414     end
415   end
416 
417   raise Sequel::Error, "array parsing finished with array unclosed"
418 end