Microfeatures I'd like to see in more languages

Post by Aaargh20318 » Thu, Jan 05, 2023, 11:33 PM UTC

amalgamated_inc wrote: post #45

Elixir's sigils are amazing. There are date sigils that allow you to do what the OP does: ~N[2023-01-01 12:00:00] But you can also define your own sigils to create new "custom syntax" for almost any struct. Kind of a special case of reader macros, I guess. Very convenient.

    extension Date: ExpressibleByStringLiteral {
        public init(stringLiteral value: String) {
             // parse the string here. 
        }

    }

    let happyNewYear: Date = “2023-01-01 12:00:00”

Post by duped » Thu, Jan 05, 2023, 11:41 PM UTC

robertlagrant wrote: post #150

duped wrote: post #64

> Second, what if parameter blocks were abstractable? Sounds like a great way to make unreadable code #define STANDARD_EXP_PARAMS ... // I hit gotodef on func(...) and got here. What are the arguments? void func (STANDARD_EXP_PARAMS) { // ... long function body ... x = y; // What is the type of x? Is it an argument or a local? } I'd really be irritated if someone ever used this feature, optimizing for lines written i…

You could say the same about a function call or a function that takes an object as an argument - who knows what code lies behind the impenetrable barrier of structured or object oriented programming?

Post by jlokier » Thu, Jan 05, 2023, 11:43 PM UTC

andix wrote: post #126

kaba0 wrote: post #118

Earlier quoted context omitted.

I really like Scala’s `val` vs `var`.

Okay, that would confuse me. Looks very similar and easy to overlook.

Post by krapp » Thu, Jan 05, 2023, 11:50 PM UTC

dragonwriter wrote: post #185

krapp wrote: post #181

Omitting parens in a function signature when calling with one or no arguments.

This means you can’t reference the function itself by name without some kind of quoting construct or other circumlocution; also, while the no-arg case might make sense as a special case, if you allow the one arg case, you might as well admit the general case.

Post by ablob » Thu, Jan 05, 2023, 11:51 PM UTC

masklinn wrote: post #97

unnouinceput wrote: post #69

Earlier quoted context omitted.

That's for languages that can't define arrays with custom start/stop indexes. But those that have custom indexes they can very easily expand/implement as helper class (for example array.indexFromLast(1) which means array[Length(array)]. This way you can have best of both worlds.

Surely if your language has custom indexes / ranges `Length(array)` is completely broken and the language provides something like "Index`Last" you can hook on? Because an array with indexes [3, 7) has length 4, but 4 is not the index of the last element.

  3 -> 0
  4 -> 1
  5 -> 2
  6 -> 3

  arr[(x,y)] = backing_array[x / 5 + y] //bounds checks omitted