Sigh, <> isn't the only way, D (as usual) has a very simple and clever solution f!(types)(parameter)

Maybe it's just my julia indoctrination speaking but I find that rather ugly.

In julia, f!(types)(parameter) means that f! is a mutating function acting on types which returns a closure which is then called on parameter.

We just write Type{paramemer}

> "We just write Type{paramemer}"

It seems odd to say "we just write" for some arbitrary choice with its own tradeoffs; {} mean a set in Python or a literal array initialiser in C# or a scriptblock in PowerShell or a dfn in Dyalog APL or a JSON dictionary, etc. With only a limited set of whatever symbols happened to end up on a US ASCII keyboard 40+ years ago, there is heavy competition for them, it's why J broke the symmetry of pairs and went for two-character symbols, why PowerShell went for comparators like -gt and -lt, why C# has => which is completely different from <=, why << is not a double application of less-than but is bit shifting ...

To act like there's an objectively better use for {} is to miss how many tradeoffs there are, and how many things people want symbols for out of a standard keyboard.

I never said it was objectively better.

My point was just that we find Type{parameter} to be nice pleasing syntax, and so reserved the curly braces for that.

Of course it’s not objectively better, that’s a dumb attitude towards syntax.

What's the difference to you for using {} vs <>?

< and > are comparison operators for checking if something is less than or greater than something else.

This is okay in a static language where there are special slots for a type where only a restricted subset of things can happen. You'd know at the parser level that the < and > are referring to the type meaning or the operator meaning.

In julia, types are values and values can live in types, and arbtrary operations can happen in a type.

E.g. I can write Tuple{1 < 2} which just becomes the type Tuple{true}, i.e. a Tuple Type with paramemter True.

I feel like this is a solvable problem. For instance you could require parens in the case of expressions using < or > characters.

Or you could just not use them for type parameters. That's also a solution for what it's worth. I think the curly braces look better as type params anyways imo.