From: Doug Beaver <doug@...>
Date: 2003-07-16T03:14:55+09:00
Subject: += vs << when appending arrays to an array

hello,

i'm looking for a nice idiomatic way to append to an array.  i'm porting
some encryption code from C to ruby, i don't have the code in front of
me but a relevant example is below:

def translate(str="")
  ret = []
  str.each_byte { |byte| ret << byte }
  ret
end

bytes = []
bytes << translate("foo")
bytes += translate("foo")

p bytes

i'm using ruby 1.6.8, btw...

elsewhere in my code, i'm using << to append bytes onto the bytes array,
but for the functions that return arrays of bytes, i have to use += to
make sure the flattened values get added to the target array.  if i use
<<, it appends the array returned from the function back onto the target
array.  i'd like to use << everywhere as it makes the code more readable
(imo), so is there some syntax i can throw in front of the translate()
call to make the << do the right thing?

i've considered both overloading Array.<< or making my own subclass and
making a smarter <<.  i realize that << can't tell if your intent is to
append the array itself ([1,2,3]) or its values (1,2,3).  i guess my
real question is, can i get the desired behavior without making a
subclass or redefining <<?  i hope my question is clear...

thanks,

doug

-- 
"Contrary to what most people say, the most dangerous animal in the
world is not the lion or the tiger or even the elephant.  It's a shark
riding on an elephant's back, just trampling and eating everything they
see." -- Jack Handey