undefined | Better HN

0 pointstxcwpalpha6y ago0 comments

> := is the assignment operator in tons of languages

It is? Which ones? Other than Go, I can not think of a single language that has ":=" as an operator. Java does not, JavaScript does not, C/C++ do not, Ruby does not, I don't think PHP does, Erlang/Elixir do not, Rust does not... (I could be wrong on these, but I've personally never seen it in any of these languages and I can't find any mention of it in these languages' docs).

I tried looking around the internet at various popular programming languages and the only ones I could find that use ":=" are: Pascal, Haskell (but it's used for something else than what Python uses it for), Perl (also used for something else), and Scala (but in Scala it isn't officially documented and doesn't have an 'official' use case).

I don't have a strong opinion about ":=" in Python but I do agree that it's unintuitive and thus not very "Pythonic".

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pavon6y ago

It was the assignment operator in Algol, which along with Fortran and Lisp was one of the most influential programming languages for decades. Its basic syntax was the prototypical "psuedo-code" in textbooks for decades after that.

The operator was inherited by Pascal, Ada, Delphi. That line of language syntax died off in the late 90's though, so I can see why younger (and in particular self-taught) programmers wouldn't be familiar with it.

hathawsh6y ago

See: https://en.wikipedia.org/wiki/Assignment_(computer_science)#...

At least 18 prominent languages use that syntax.

megla_6y ago

I genuinely haven't heard of 13 of those and I'd say I'm quite interested in learning about languages. The few that I know, were just briefly mentioned by a professor, so I don't know anything apart from the name.

What qualifies as prominent to you? How old are you? On Tiobe Index only Pascal and Go are in the first 50, while half of them aren't even listed in the first 100. Sure they're important and had an impact on new languages, but most of them were made ~50 years ago.

So many new languages were developed since then, which are far more useful and prominent than these legacy ones. If almost none of the modern ones have implemented it so far, is it really that useful/needed?

coldtea6y ago

>I genuinely haven't heard of at least a third of them and I'd say I'm quite interested in trying new (and possibly unusual) languages.

But perhaps not as interested in trying old and significant languages?

>What qualifies as prominent to you? On Tiobe Index only Pascal and Go are in the first 50, while half of them aren't even listed in the first 100. Sure they're important and had an impact on new languages, but most of them were made ~50 years ago.

Well, Lisp was made 60+ years ago, and C 50 years ago, so?

Besides Go, Smalltalk, Ada, and Pascal would be significant languages in any book, and I'd add Simula, Oberon, Eiffel, and Dylan to the list.

Seriously, if one haven't at least heard of Simula (the father language of OO) I'm not sure how qualified they are to pass PL judgement.

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Redoubts6y ago

> At least 18 prominent languages use that syntax.

There aren't even 18 prominent languages...

txcwpalphaOP6y ago

That's more than I was aware of, but I would hardly call 90% of those "prominent". Sorry to any fans of those languages, but I doubt even most people here on HN have even heard about over half of the languages in that ":=" list.

coldtea6y ago

If someone is not, not a user, but familiar with ALGOL, Simula, Pascal, Modula, Ada, PL/M, Smalltalk, Eiffel, and Oberon, they should not really promote their programming language ideas as relevant...

The fact that they use some "new languages" (e.g. whatever derivative stuff happens to be in fashion atm) and are not even aware of the debt of those languages to the list above, doesn't qualify them...

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dwohnitmok6y ago

It shows up fairly frequently in pseudocode, especially for BNF syntax rules. I also (probably as a result) have come across it often-ish in embedded DSLs if the host language already uses = for assignment.

So from the perspective of Python as executable pseudocode it makes some sense.

CraneWorm6y ago

Pascal uses := as an assignment operator.

Actually, there are a lot of other variants assignments get written in various computer languages. https://en.wikipedia.org/wiki/Assignment_(computer_science)#...

kxrm6y ago

Delphi uses this as an assignment operator but it certainly isn't a popular choice in most mainstream languages.

girzel6y ago

And Ocaml:

https://ocaml.org/learn/tutorials/structure_of_ocaml_program...

thestoicattack6y ago

In Ada, = is equals and := is assignment.

beachy6y ago

Oracle's PL/SQL uses it. I believe it was based on ADA... googles ... Yes ADA uses it as well.

j / k navigate · click thread line to collapse

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pavon6y ago

hathawsh6y ago

See: https://en.wikipedia.org/wiki/Assignment_(computer_science)#...

At least 18 prominent languages use that syntax.

megla_6y ago

coldtea6y ago

>I genuinely haven't heard of at least a third of them and I'd say I'm quite interested in trying new (and possibly unusual) languages.

But perhaps not as interested in trying old and significant languages?

Well, Lisp was made 60+ years ago, and C 50 years ago, so?

Besides Go, Smalltalk, Ada, and Pascal would be significant languages in any book, and I'd add Simula, Oberon, Eiffel, and Dylan to the list.

Seriously, if one haven't at least heard of Simula (the father language of OO) I'm not sure how qualified they are to pass PL judgement.

1 more reply

Redoubts6y ago

> At least 18 prominent languages use that syntax.

There aren't even 18 prominent languages...

txcwpalphaOP6y ago

coldtea6y ago

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dwohnitmok6y ago

So from the perspective of Python as executable pseudocode it makes some sense.

CraneWorm6y ago

Pascal uses := as an assignment operator.

Actually, there are a lot of other variants assignments get written in various computer languages. https://en.wikipedia.org/wiki/Assignment_(computer_science)#...

kxrm6y ago

Delphi uses this as an assignment operator but it certainly isn't a popular choice in most mainstream languages.

girzel6y ago

And Ocaml:

https://ocaml.org/learn/tutorials/structure_of_ocaml_program...

thestoicattack6y ago

In Ada, = is equals and := is assignment.

beachy6y ago

Oracle's PL/SQL uses it. I believe it was based on ADA... googles ... Yes ADA uses it as well.

j / k navigate · click thread line to collapse