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RE: [Caml-list] String to list to string
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Date: -- (:)
From: brogoff <brogoff@s...>
Subject: RE: [Caml-list] String to list to string
On Thu, 10 Feb 2005, Harrison, John R wrote:
> | > Haskell treats strings as lists of chars by default.
> |
> | Just goes to show you that even really smart people can do some
> amazingly
> | dumb things.
> That's far too categorical; opinions differ on this subject.
> I'd be
> quite
> happy with strings as lists of characters, and I consider OCaml's
> mutable
> strings a far worse design error.

I disagree. Given strings as lists, or even something not as ridiculous, like
ropes (which Pierre Weis said existed in an older Caml) the programmer can
not write an efficient mutable string over it.  And, mutability aside, string
algorithms usually view strings as arrays, not lists. At least the other lazy
language gets this right. You would penalize almost all nontrivial string
manipulation programs if we fixed this "design error" with the approach you
find less odious.

IMO, the problem is that no one string (or array) type suffices for all or even
most purposes, and without some kind of overloading, having say five or six
different string types becomes notationally heavy.

So, while I'd love to have immutable strings, if there is going to be just one
privileged string type in OCaml, I think mutable strings are a reasonable
choice, not an error. Error is far too categorical.

> And yes, I use "implode" and "explode" all the time,

Have you no shame, to broadcast these perversions in a group which may have
young programmers? Really! ;-)

> because lists of
> characters are often simple and convenient to deal with in a functional
> style, and string manipulations are almost never performance-critical
> in the kind of code I write.

And you can (but shouldn't!) write those functions in your sleep in a few lines
of ML, over the existing mutable strings.

My preference for functional string processing is, as I said, substrings.
They are convenient, and encapsulate the index manipulations in the
data type. I'm almost certain you've seen them, what's your issue?

-- Brian