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Elm for the Front End, Right Now

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Re: Elm for the Front End, Right Now

#41

Post by agumonkey »

striking wrote: post #37
agumonkey wrote: post #23

Earlier quoted context omitted.

Completely logical. Java, C, PHP are said to be algol descendants. In two words: curly braces. JS wasn't supposed to but ended up curly because social trends are that strong. Now imagine JS function being the only thing you use, then that language users and designers evolving a syntax for typed js-like functions, rince repeat, you get ML, Haskell, Elm. In time your brain realigns, depending on how much you appreciate…

Not quite. ALGOL doesn't have curly braces, just BEGIN and END blocks. BEGIN FILE F (KIND=REMOTE); EBCDIC ARRAY E [0:11]; REPLACE E BY "HELLO WORLD!"; WHILE TRUE DO BEGIN WRITE (F, *, E); END; END. I've heard it said that the languages you mentioned are inspired by C's syntax.

Wow, couldn't be more wrong. It's indeed C family (BCPL, B). Thanks a lot for the note.

Re: Elm for the Front End, Right Now

#42

Post by kcarnold »

I really want to like Elm. When I'm writing JS/React code, I sometimes think "this would be so much nicer in Elm!" - especially for architectural issues. But the few times I’ve actually tried doing something in it, I find that the parts of what I want to do that fit cleanly within Elm’s walls are really nice, but the parts that don’t quite fit get hard quickly. Suppose I want to do something with the DOM that doesn’t quite fit into virtual-dom’s model -- I suddenly have to make a complicated JS interop and work around things to get at the raw DOM node... whereas with React I can just hack something together, try it with users, and learn that I should actually be doing something completely different anyway. Or maybe I don’t actually know yet what I want to have happen in every possible condition? Maybe I feel this way because I just don’t have enough experience, but it may be a fundamental trade-off involved in how Elm makes it hard to do things wrong.

Has anyone had some positive experiences with prototyping / rapid design iteration with Elm and can share some tips / encouragement?

Re: Elm for the Front End, Right Now

#43

Post by mikekchar »

agumonkey wrote: post #41
striking wrote: post #37

Earlier quoted context omitted.

Not quite. ALGOL doesn't have curly braces, just BEGIN and END blocks. BEGIN FILE F (KIND=REMOTE); EBCDIC ARRAY E [0:11]; REPLACE E BY "HELLO WORLD!"; WHILE TRUE DO BEGIN WRITE (F, *, E); END; END. I've heard it said that the languages you mentioned are inspired by C's syntax.

Wow, couldn't be more wrong. It's indeed C family (BCPL, B). Thanks a lot for the note.

Well, I wouldn't be so hard on yourself. IIRC (and I hope someone corrects me if I'm wrong), algol introduced block scoping. Whether you use BEGIN/END or {/} I think is a pretty minor point.

C has braces to introduce a new scope. The irony is that JS (until recently) didn't have block scope. It just has braces :-).

Now this is where it gets screwy. You are supposed to (but don't have to usually) add a semi-colon on the end of each statement in Javascript.

a = 52;

This has a semi colon because it is a statement. There is another construct called an expression. An expression is anything that can evaluate to a value. An statement can be an expression (the statement "a = 52;" is an example of that because it also evaluates to 52 and is thus an expression). But there are expressions that are not statements. Here is an example of an expression

(5 * 27)

It evaluates to a value, but doesn't do anything so it is not a statement. Usually in computer languages, if "statements" are actually expressions. So you can say

if (1>0) {"Yay"} else {"Boo"}

evaluates to a value ("Yay" in this case), but doesn't do anything in and of itself. The blocks in the braces may contain statements, but the if is an expression, not a statement. Note the lack of semi-colon. Again, presumably because it is an expression, not a statement.

You can try the above in Node and it will indeed return the value "Yay".

a = if(1>0) {"Yay"} else {"Nay"};

In this case the variable a should be assigned the value "Yay", because the if expression evaluates to a "Yay". For some strange reason (that I don't understand), Javascript (or at least Node, when I tried it) does not accept that. It gives you a syntax error. You can not use if "statements" as expressions in Javascript (which sucks quite a bit).

All of this to say that Javascript appears broken to me, no matter what geneology you assign to it :-D. I personally really like programming in JS (or actually CS), but it is a beast unto itself, I think.

I'd welcome comments illuminating this issue if I've made a mistake with the above! As I said, it's easy to do.

Re: Elm for the Front End, Right Now

#44

Post by kinkdr »

salimmadjd wrote: post #15
ggregoire wrote: post #6

From what languages is Elm inspired? I've a Java/C#/PHP/JS background and I feel really uncomfortable with Elm syntax.

when I spoke with Evan (you can usually meet him at the Elm SF meetup) I believe he said Elm was inspired more by OCaml than Haskell. But since many people might have heard of Haskell more than OCaml, Haskell is a better general answer.

The syntax is closer to Haskell than Ocaml.

Foe example types in Ocaml usually start with lower letter.

Also Elm has "Maybe", just like Haskell, instead of "option" of Ocaml.

Also in Elm, like in Haskell you would write "List Sometype", while in Ocaml it is "sometype list".

Re: Elm for the Front End, Right Now

#45

Post by agumonkey »

mikekchar wrote: post #43
agumonkey wrote: post #41

Earlier quoted context omitted.

Wow, couldn't be more wrong. It's indeed C family (BCPL, B). Thanks a lot for the note.

Well, I wouldn't be so hard on yourself. IIRC (and I hope someone corrects me if I'm wrong), algol introduced block scoping. Whether you use BEGIN/END or {/} I think is a pretty minor point. C has braces to introduce a new scope. The irony is that JS (until recently) didn't have block scope. It just has braces :-). Now this is where it gets screwy. You are supposed to (but don't have to usually) add a semi-colon on t…

True but my algol mention was strongly on syntax not semantics (big part of algol contribution).

Re: Elm for the Front End, Right Now

#46

Post by eastWestMath »

skybrian wrote: post #34
eastWestMath wrote: post #25

Earlier quoted context omitted.

Or maybe people could just become familiar with ML-style languages? The basic syntax shouldn't take more than an hour or two to pick up.

Well sure, but you could say the same thing about Lisp.

Well they're both the lambda calculus, Lisp just had parentheses.

Re: Elm for the Front End, Right Now

#49

Post by nv-vn »

matt4077 wrote: post #29
kinkdr wrote: post #22

Earlier quoted context omitted.

> it would sound like there was some critical change to the core functionality of the language No, I acknowledged early on, and many times, that it is a very minor thing. My only concern is that it is worrying for the future. (Using the word huge in the "huge red flag" was an exaggeration. I shouldn't have done so). > 1. It confuses newbies. Remove it from core language then. Having the prime character in my code, do…

> Remove it from core language then. Having the prime character in my code, doesn't confuse anyone but me. Until you take your personal style to Github, or coworkers... Evan is doing a pretty good job at managing Elm – in fact I don't know any other language except maybe Swift where the rollout is planned to such a depth.

If coworkers are unhappy with it, they can (and should) make guidelines for acceptable syntax. This is no different than using camel case in Java instead of snake case (or using the $ in identifiers, which is extremely rare). If it's a problem to use it in my code on Github, you can always use somebody else's code or fork mine to change it. Maybe we should use the compiler to force every line to have a comment so we don't have any undocumented code on Github too?

Re: Elm for the Front End, Right Now

#50

Post by kazinator »

eastWestMath wrote: post #46
skybrian wrote: post #34

Earlier quoted context omitted.

Well sure, but you could say the same thing about Lisp.

Well they're both the lambda calculus, Lisp just had parentheses.

Does lambda calculus have character strings, structures, exceptions, symbols, mutable variables, quoting code as data, macros and three different kinds of object equality?
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