Method: BibTeX::Bibliography#query

Defined in:
lib/bibtex/bibliography.rb

#query(*arguments, &block) ⇒ Object Also known as: q

call-seq:

bib.query()          #=> returns all elements
bib.query('@book')   #=> returns all books
bib.query('@entry')  #=> returns all entries (books, articles etc.)
bib.query('@*')      #=> same as above
bib.query(:first, '@book, @article')
  #=> returns the first book or article or nil
bib.query('@book[year<=2011], @article)
  #=> returns all books published in 2011 or earlier and all articles
bib.query('@book, @article) { |o| o.year == '2011' }
  #=> returns all books and articles published in 2011
bib.query('@book[year=2011], @article[year=2011])
  #=> same as above without using a block

Returns objects in the Bibliography which match the given selector and, optionally, the conditions specified in the given block.

Queries offer syntactic sugar for common enumerator invocations:

>> bib.query(:all, '@book')
=> same as bib.select { |b| b.has_type?(:book) }
>> bib.query('@book')
=> same as above
>> bib.query(:first, '@book')
=> same as bib.detect { |b| b.has_type?(:book) }
>> bib.query(:none, '@book')
=> same as bib.reject { |b| b.has_type?(:book) }



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# File 'lib/bibtex/bibliography.rb', line 465

def query(*arguments, &block)
  case arguments.length
  when 0
    selector = :all
    q = nil
  when 1
    selector = :all
    q = arguments[0]
  when 2
    selector, q = arguments
  else
    raise ArgumentError, "wrong number of arguments (#{arguments.length} for 0..2)"
  end

  filter = block ? proc { |e| e.match?(q) && block.call(e) } :
    proc { |e| e.match?(q) }

  send(query_handler(selector), &filter)
end