"map" keyword?

[vodish]

Why do we have to declare a map using the "map" keyword?

map[string]int{}

Why can't we just do it this way?

[string]int{}

[JalonSolov]

[]int{} means an int array.

[5]int{} means a fixed size int array.

[string]int{} is a syntax error, because string is not a literal.

In other words, it would be too confusing against other existing syntax.

[vodish]

It looks like a solvable problem.

If there are letters in square brackets, it's a map.

[JalonSolov]

Or just an error, because you typed the wrong thing.

This would add a lot of complexity to the parser, in place of just typing the 3 characters, map.

[vodish]

The parser handles capital letters for type names perfectly ))

[vodish]

map[string]map[Foo]map[int]Bar{} 

Or

[string][Foo][int]Bar{} 

[jorgeluismireles]

map's keys can be uppercase types for enums or alias. Would be practically impossible to differentiates complex groups.

enum Enum { a b c }
type Int = int

fn main() {
	mut m := map[Enum]string{}
	m[.a] = 'a'
	dump(m)
	mut n := map[Int]string{}
	n[0] = 'b'
	dump(n)
}

[vodish]

1. First, define the type
2. Then expand the values there

[gechandesu]

The syntax without the map keyword would be too implicit for the programmer. Just by looking at the map declaration, it's immediately clear what we're dealing with. Without it, it would be harder to distinguish map from an array.

[TypeA]TypeB{} // map with TypeA keys and TypeB values
[asize]TypeC{} // fixed size (asize) array of TypeC values

Yes, the case of the letters makes it clear that TypeA is a type, not a variable name, and asize is a variable. Anyone reading the code will have to think about this.

We'll save a few characters at the cost of code readability and parser complexity. I'd leave things as is.