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Comment by agentgt | Hacker News Reader

I have the same problem with almost all new languages including Rust: everything should be an expression and not a statement.

Even conditional logic constructs (if/else) should be an expression (i.e. return a value).

The language doesn't even have to be pure or hard core FP to follow this philosophy.

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Actually, in Nim almost everything is an expression, including if blocks, case, and even except blocks.

Together with immutable "variables" (let) this encourages a pretty functional style. I'd just wish their support for lambdas and list comprehensions would be a bit better.

I highly agree, especially about the if/else. The more I code, the more I try to elimante branching. If statements as expressions would be ideal.

Most mainstream languages (C, Java, etc) have this. The ternary operator ?:

That's like farting in the bathtub and calling it a hot tub.

Why? It is an expression, not a statement regardless of your farting nonsense.

Because they aren't the same thing.

Based on my understanding, Rust is an expressive language. What have you seen that is not expressive?

You are mistaken about rust. I can't think of a construct that is not an expression.

    let x = 5;

(That said, very nearly everything is an expression, yes)

I don't know about Rust; but in ML family, everything in top level is a binding. Whether it's a variable, function, type or structure.

SML is explicit about it and its syntax makes it clear what type of binding is going on.

val x = 5

fun f = fn x => x * x

datatype weekend = Sat | Sun

So while on top level not everything is an expression, everything on the RHS is an expression.

In rust, assignment isn't an expression, but everything else is.

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