The idea is that Parsec represents a grammar, similar to BNF with <|> giving alternative rules. So something like:

    atom =  many digit
        <|> identifier
        <|> stringLiteral
        <|> between (char '(') (char ')') expression

I can't imagine any way this would look better with a name instead of the <|> operator. You could write it something like:

    atom = many digit
        `or` identifier
        `or` stringLiteral
        `or` between (char '(') (char ')') expression

but that's no clearer and a bit harder to follow. With a much longer identifier than "or", it would be completely unreadable. If you had to make "or" prefix (the `` let you use a normal function in infix position), it would be even less readable. Combine the two (a longer, prefix identifier) and you have an even bigger mess!

The operators let you see the structure of an expression at a glance. You don't have to read the whole thing to figure out what's going on. Moreover, the <|> symbol is pretty intuitive--it's clearly based on | which usually represents some sort of alternation.

> chc: I do not think Parsec would be better off if "<|>" were renamed to "parsecOR"

> sanderjd: I do think Parsec would be better off if "<|>" were something like "parsecOR"

Do you think perhaps some people think about functions visually while others think about them auditorily?

An IDE could easily render function names however the human reader wants. The option whether to render function names as names or symbols would be customizable, just like the display colors for various element types are.

Within each option, there's further choices. For names, there could be a choice between various natural languages. For symbols, it could be restricted to ASCII e.g. <|>, or full Unicode, e.g. | enclosed by a non-spacing diamond.

If you're really interested in this, I'd encourage you to take some actual Parsec code and make this change, then compare the two for readability. My guess is that while it's conceptually nice, you'll find in practice it hampers readability more than it helps.