[zahlman]

> Contrast an Algol-descendant like C, Pascal, Java, or even Python with a pure functional language like Haskell. In the former, control structure names are reserved words and control structures have a distinct syntax. In the latter, if you see `foo` in the body of a function definition you have no idea if it's a simple computation or some sophisticated and complex control structure just from what it looks like. The former provides more clues, which makes it easier to decipher at a glance. (Not knocking Haskell, here; it's an interesting language. But it's absolutely more challenging to read.)

For what it's worth, Python has been moving away from this, taking advantage of a new parser that can implement "soft keywords" like 3.10's "match" statement (which I'm pretty sure was the first application).

Believe it or not, the motivation for this is to avoid reverse compatibility breaks. Infamously, making `async` a keyword broke TensorFlow, which was using it as an identifier name in some places (https://stackoverflow.com/questions/51337939).

In my own language design, there's a metaprogramming facility that lets you define new keywords and associated control structures, but all keywords are chosen from a specific reserved "namespace" to avoid conflicts with identifiers.

[wduquette]

I don't have any real problem with words that are reserved absolutely and words that are reserved just in particular places. My point was more that in Algol-derived languages control structures look like control structures. And even in languages that implement `map()` and other higher-order functions, you can tell that it's a method/function call and that these things are being passed to it and those other things are not without going and looking up what `map()` does.