Method: Array#fetch

Defined in:

ext/enterprise_script_service/mruby/mrbgems/mruby-array-ext/mrblib/array.rb

#fetch(n = nil, ifnone = NONE, &block) ⇒ Object

call-seq:

   ary.fetch(index)                    -> obj
   ary.fetch(index, default)           -> obj
   ary.fetch(index) { |index| block }  -> obj

Tries to return the element at position +index+, but throws an IndexError
exception if the referenced +index+ lies outside of the array bounds.  This
error can be prevented by supplying a second argument, which will act as a
+default+ value.

Alternatively, if a block is given it will only be executed when an
invalid +index+ is referenced.

Negative values of +index+ count from the end of the array.

   a = [ 11, 22, 33, 44 ]
   a.fetch(1)               #=> 22
   a.fetch(-1)              #=> 44
   a.fetch(4, 'cat')        #=> "cat"
   a.fetch(100) { |i| puts "#{i} is out of bounds" }
                            #=> "100 is out of bounds"

# File 'ext/enterprise_script_service/mruby/mrbgems/mruby-array-ext/mrblib/array.rb', line 304

def fetch(n=nil, ifnone=NONE, &block)
  warn "block supersedes default value argument" if !n.nil? && ifnone != NONE && block

  idx = n
  if idx < 0
    idx += size
  end
  if idx < 0 || size <= idx
    return block.call(n) if block
    if ifnone == NONE
      raise IndexError, "index #{n} outside of array bounds: #{-size}...#{size}"
    end
    return ifnone
  end
  self[idx]
end