Class Sequel::Postgres::PGArray::Parser
In: lib/sequel/extensions/pg_array.rb
Parent: 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

new   new_entry   parse  

Public Class methods

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.

[Source]

     # File lib/sequel/extensions/pg_array.rb, line 311
311:         def initialize(source, converter=nil)
312:           super(source)
313:           @converter = converter 
314:           @stack = [[]]
315:           @encoding = string.encoding
316:           @recorded = String.new.force_encoding(@encoding)
317:         end

Public Instance methods

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

[Source]

     # File lib/sequel/extensions/pg_array.rb, line 321
321:         def new_entry(include_empty=false)
322:           if !@recorded.empty? || include_empty
323:             entry = @recorded
324:             if entry == 'NULL' && !include_empty
325:               entry = nil
326:             elsif @converter
327:               entry = @converter.call(entry)
328:             end
329:             @stack.last.push(entry)
330:             @recorded = String.new.force_encoding(@encoding)
331:           end
332:         end

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

[Source]

     # File lib/sequel/extensions/pg_array.rb, line 336
336:         def parse
337:           raise Sequel::Error, "invalid array, empty string" if eos?
338:           raise Sequel::Error, "invalid array, doesn't start with {" unless scan(/((\[\d+:\d+\])+=)?\{/)
339: 
340:           while !eos?
341:             char = scan(/[{}",]|[^{}",]+/)
342:             if char == ','
343:               # Comma outside quoted string indicates end of current entry
344:               new_entry
345:             elsif char == '"'
346:               raise Sequel::Error, "invalid array, opening quote with existing recorded data" unless @recorded.empty?
347:               while true
348:                 char = scan(/["\\]|[^"\\]+/)
349:                 if char == '\\'
350:                   @recorded << getch
351:                 elsif char == '"'
352:                   n = peek(1)
353:                   raise Sequel::Error, "invalid array, closing quote not followed by comma or closing brace" unless n == ',' || n == '}'
354:                   break
355:                 else
356:                   @recorded << char
357:                 end
358:               end
359:               new_entry(true)
360:             elsif char == '{'
361:               raise Sequel::Error, "invalid array, opening brace with existing recorded data" unless @recorded.empty?
362: 
363:               # Start of new array, add it to the stack
364:               new = []
365:               @stack.last << new
366:               @stack << new
367:             elsif char == '}'
368:               # End of current array, add current entry to the current array
369:               new_entry
370: 
371:               if @stack.length == 1
372:                 raise Sequel::Error, "array parsing finished without parsing entire string" unless eos?
373: 
374:                 # Top level of array, parsing should be over.
375:                 # Pop current array off stack and return it as result
376:                 return @stack.pop
377:               else
378:                 # Nested array, pop current array off stack
379:                 @stack.pop
380:               end
381:             else
382:               # Add the character to the recorded character buffer.
383:               @recorded << char
384:             end
385:           end
386: 
387:           raise Sequel::Error, "array parsing finished with array unclosed"
388:         end

[Validate]