<@U3E25GSEP> And I think you can replace `claims.m...

# advent-of-code

[karelpeeters]

@robin And I think you can replace claims.map { it.cells }.reduce { ... } with claims.flatMap { }.

[robin]

Oh wow, you're right! I use flatMap so often I'm surprised I didn't think of that 😄 It even speeds up my solution almost 2x

[karelpeeters]

And other suggestion (but maybe you just prefer it this way) x..(y-1) is x until y.

[robin]

Right! I added the -1 later when I realized I had an off-by-one, so didn't think to switch to until

[karelpeeters]

Idea should have a warning for this 😉

[robin]

It does! It just doesn't seem to get triggered if the second argument is in parens 😄

[karelpeeters]

I don't even want to know what the code for inspections looks like if parenthesis break it.

[robin]

Probably works on the AST, and just evaluates the top-level expression that makes up the righthand operator, und doesn't evaluate subexpressions for performance reasons or something like that. Although allowing parenthesis around it seems trivial

[karelpeeters]

But why are parentheses part of the AST 🙁

[robin]

Because it's the Abstract Syntax Tree, and parens are part of the language syntax 🤷

[karelpeeters]

Well it's also the Abstract Syntax Tree 🧌

[karelpeeters]

Haha I remember reading this on wikipedia:

The syntax is "abstract" in the sense that it does not represent every detail appearing in the real syntax, but rather just the structural, content-related details. For instance, grouping parentheses are implicit in the tree structure [...]

[karelpeeters]

Maybe it's different for an IDE because it actually needs to know about them.

[robin]

Yeah, there are also inspections like "remove unnecessary parenthesis" so IntelliJ definitely needs to know about them in the source representation it uses for inspections. Maybe that's a separate stage before the AST though, no idea.