I've been programming professionally for 25 years using mostly C inspired languages, and I will still regularly write "if(foo = bar)" on a daily basis and not notice until there's an error. It's easily the most common syntax error I write, followed closely by using commas in my for-loop as apparently it looks like a function to my fingers: "for(x=0, x<10, x++)"
Why Does “=” Mean Assignment?
41–50 of 367 posts
Re: Why Does “=” Mean Assignment?
#42Is it really worth allowing assignment in places so weird that you also need ==? Wouldn't it be easier to use = for everything and get rid of those weird edge cases?
Yeah I was pretty surprised when I found out that assignment and equality can be totally syntactically separate and nonambiguous with miminal language-design effort. Just get rid of the silly idea of allowing expressions as statements.
Although even then it's nice to use different symbols because they are different meanings. I don't like it when a word has different meanings depending on context.
Re: Why Does “=” Mean Assignment?
#43because in math it means assignment. y = mx+b
That is an assignment. There is also a math symbol that specifically designates equivalence.
Re: Why Does “=” Mean Assignment?
#44I always read it with an implied "let" in front, so it has always sounded completely natural. It's also ergonomic to type, easy to read and while you can confuse := and = on account of : being a small glyph even in monospace fonts - you can mistake it for empty space if you're just skimming, == and = are harder to confuse since one is twice as long as the other.
Re: Why Does “=” Mean Assignment?
#45Should be ->
Or perhaps <-
Re: Why Does “=” Mean Assignment?
#46Bcpl still exists in 2018?
I worked two jobs where we used BCPL. Not since 1990 or so though..
Re: Why Does “=” Mean Assignment?
#47because in math it means assignment. y = mx+b That is an assignment. There is also a math symbol that specifically designates equivalence.
No. It does not.
Re: Why Does “=” Mean Assignment?
#48Another interesting way to think about it is as "match". That is try to match the stuff on the right with the stuff on the left. Take Erlang for example: 1> X = 1. 1 2> X = 2. ** exception error: no match of right hand side value 2 Notice variables are immutable (not just values themselves). Once X becomes 1, it can only match with 1 after that. You might think this is silly or annoying, why not just allow reassignme…
Some(all?) compilers transform your code into something like this internally. Its called static single assignment form. https://en.wikipedia.org/wiki/Static_single_assignment_form
Re: Why Does “=” Mean Assignment?
#49A coworker of mine once referred to := as the 'Zoidberg operator', and the name has stuck with me since.
Re: Why Does “=” Mean Assignment?
#50Earlier quoted context omitted.
From the article: > Looking at this as a whole, = was never “the natural choice” the assignment operator. Pretty much everybody used := for assignment instead, possibly because = was so associated with equality. Nowadays most languages use = entirely because C uses it, and we can trace C using it to CPL being such a clusterfuck.
And I dispute the "pretty much everybody used" part. In fact, I think the article contradicts that opinion. Algol used it, and so did Pascal. But Pascal was only a year old [Edit: at the time the choice was made for C] - it [Pascal] hadn't set the world on fire yet (to the degree that ever did). That leaves Algol using ":=", and FORTRAN, COBOL, and Lisp not using it. That's not "pretty much everybody used".
Yeah, it's probably more accurate to say that "everybody from the Algol line used := for assignment", with C being the first language of that line to stop.