From: Bulat Ziganshin <bulatz@...>
Date: 2002-10-07T14:44:17+09:00
Subject: Re: Specifying local and external block parameters (that old chestnut)

Hello Yukihiro,

Monday, October 07, 2002, 9:16:08 AM, you wrote:

YM> Hi,

YM> In message "Re: Specifying local and external block parameters (that old chestnut)"
YM>     on 02/10/07, "Bulat Ziganshin" <bulatz@integ.ru> writes:

YM> |i personally think that this usage will be very strange nad
YM> |untraditional. for me, it is better to use '=' for constant assignment
YM> |and ':=' for variable assignment, as done in algol-68 and in some
YM> |modern FP languages

YM> Could you describe "constant assignment" and "variable assignment" in
YM> algol-68 bit more in depth?

int a=1;    -- declaring a with type 'int' and value 1
int b:=2;   -- declaring b with type 'pointer to int' and value of
pointing to cell of type int, whose INITIAL VALUE will be 2

b:=3;  -- correct. b will point to the same cell which value is
however changed

a:=4; -- INCORRECT. we can't change value of a


well, a whole algol-68 is STRONG language (in two or more senses ;)

common idea is that after '=' we can't change value, but after ':=' we
can. btw, even subroutines declared in algol-68 with '=' to closures



-- 
Best regards,
 Bulat                            mailto:bulatz@integ.ru