[a_lieb]

I've always wondered if a good way to do infix would be to simply have the ability to mark an item with a character that means "move this to the front of the expression." Let's say the char is ":". Then this:

  (1 :+ 2)

Would be converted to this:

  (+ 1 2)

It would also allow for arbitrary placement, so you can do goofy stuff like pretend to be Forth without writing custom macros for the situation:

  (1 2 3 4 5 :+)

Whether or not that part is an advantage is another story ;)

This doesn't solve the "too many parens" problem, because you still have parens, but it does solve the "prefix math looks weird" problem. It's quite a bit simpler than what Dylan does, in that there's no special concept of "binary operators" and it's obvious at a glance how everything converts to sexps.

[hyperion2010]

Racket currently has something like this for certain operators. `. -> . ` will allow the arrow to sit in between inputs and outputs in contracts.

[darkpuma]

> for certain operators

AFAIK it works for any operator that takes two operands (or more, but it makes less sense to be using it with three or more operands.)

e.g:

    > '(arg0 . operator . arg1 arg2)
    '(operator arg0 arg1 arg2)

[a_lieb]

Ah, interesting—thanks for pointing that out. That is practically the same thing. I only wonder if the fact that it's two dots tends to discourage it from general use for things like arithmetic, compared to a single character.

[slaymaker1907]

You could do this in Racket by messing with #%app. Supporting arbitrary infix operators could be a bit tricky, but just doing standard math ones wouldn’t be too difficult.

[breck]

That’s an interesting idea. “Markfix” Notation?

How would it work if you had 2+ operators in one line?

[a_lieb]

Good question--just stack them up on the left on the same order as they appear in the expression, I guess.