rrrrrrrrrrrt posted:

lol, lens defense incoming!!

rrrrrrrrrrrt posted:

good god lens tutorials are the new monad tutorials

gonadic io posted:

cba, can somebody else say that yes those operators are excessive but they kinda make sense as a dsl?

VikingofRock posted:

Isn't next() is doing the same thing as dereferencing it?

rrrrrrrrrrrt posted:

I had you in mind when I wrote that.






Shameful.

horse mans posted:

fleshweasel posted:

you're making an assumption that inside the Iterator there is a chunk of memory and a pointer referencing a location in the memory, but an iterator could be doing anything to obtain the next element in its sequence.

code:

    class Fiberator implements Iterator<Integer> {
        private int secPrev = 0;
        private int prev = 0;
    
        public boolean hasNext() { return true; }
        public Integer next() {
            if (prev == 0) {
                prev = 1;
                return 1;
            }
            int current = secPrev + prev;
            secPrev = prev;
            prev = current;
            return current;
        }
        public void remove() {
            ;
        }
    }

I probably belong in this thread as well

gonadic io posted:

i know, who else would do it?

rrrrrrrrrrrt posted:

tbf i think lens is really cool but most of those operators... goddamn. pretty indefensible imo. and "it makes sense if you use them all the time and memorize these simple mnemonics!" is not a good defense.

Dessert Rose posted:

you are in this case "pointing" to the chunk of memory designated by "prev", though

iterators do whatever they want when you increment them and return whatever they want when you dereference them, you can give those operations different names if you want but that's what they do

Dessert Rose posted:

also idk if i would have put remove() on that interface and not on some other interface, FullAccessIterator or somesuch

Dessert Rose posted:

being able to define an entire iterator with a single method definition in c# is so amazing, like you don't have to janitor class definitions or state variables, just write the method that generates the next element and yield return it from the loop that you'd naturally write

VikingofRock posted:

drat that sounds sick

MononcQc posted:

FWIW, Python also does this too

code:

def fib():
    prev = 0
    prevn = 1
    while True:
        cur = prev + prevn
        prev, prevn = prevn, cur
        yield cur

>>> f = fib()
>>> next(f)
1
>>> next(f)
2
>>> next(f)
3
>>> next(f)
5
>>> next(f)
8

Dessert Rose posted:

fyi you missed the first "1", it goes 1, 1, 2, 3 ...

Bloody posted:

i want to make a program like gofmt for another language. i have a bnf grammar of the language and a vague idea of the things i would need to write to make it. this is the sort of thing that functional languages and pattern matching are good at, right? im thinking this may be an istp to learn f# with.

OldAlias posted:

it has a bad reputation. the main spots you'd go for perl knowledge are old as gently caress - design wise + if you aren't paying attention you're going to get advice from 15 years ago where people seemed to tolerate horseshit. perl is good at certain things and has been bludgeoned into other roles like any other plang. idk CPAN is at least sane to use.

Bloody posted:

i want to make a program like gofmt for another language. i have a bnf grammar of the language and a vague idea of the things i would need to write to make it. this is the sort of thing that functional languages and pattern matching are good at, right? im thinking this may be an istp to learn f# with.

abigserve posted:

Fair. It gets a lot of use still in the networking field to write scripts so I had to learn it and I like it!

JewKiller 3000 posted:

as an ocaml programmer, i recommend staying away from camlp4. it is very complicated and you probably don't need it

if you're interested in source code formatting in the ocaml world check out ocp-indent

Dessert Rose posted:

i cant decide whether it's an important difference in the java iterator interface vs the c# enumerator interface that the enumerator interface has MoveNext and Current, while the iterator interface just has next, so you can access the current value more than once with an IEnumerator

i guess it'd be easier to implement infinite sequences that conform to the java interface and it's not like it's a big deal that your calling code has to define the temp variable if it wants it

Soricidus posted:

I literally don't think I have ever used remove() on an iterator, or seen any code that uses it, or seen any iterator implementations outside the stdlib that support it

suffix posted:

i just give up every time i tr yto write a c++ iterator

afaict it's a terrible interface for anythig but iterating over an array

c++ also has weird rules for what can be initialized how, so it was hard to make temporary values with generic types iirc