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From: Jeff Garland (jeff_at_[hidden])
Date: 2006-07-04 02:57:26

Shunsuke Sogame wrote:
> Jeff Garland wrote:

> I also can't wait for the future Boost.Range,
> I'm working for my own use:
> Note that they are not fully implemented yet.

Looks interesting.

>>> The following is possible today:
>>> std::string dst = range_construct(rng|to_upper);
>>> range_copy(rng|to_upper|to_lower|to_upper, dst);
>>> Note that '|to_upper' is lazy.
>> I have no idea what this code does? Construct a range from chars that have
>> been upper-cased and write it into dst. Then copy the rng to while converting
>> it to upper, then lower, then upper? This one isn't winning me over with code
>> clarity...
> '|to_upper' makes a range of 'transform_iterator'.

Honestly, that didn't clear it up for me. What does the rest of it do? This
code doesn't make sense to me: 'to_upper|to_lower|to_upper'
It's upper, then lower, then upper -- huh?

>>> Well, IMHO, I prefer free-functions for another readability:
>> or
>> s1.replace_all(s2, s3); //obvious which string is modified here
>> Of course, you want to be able to work consistently so you have to pull along
>> the functions with less arguments too.
> The main problem is that 's1' must be a 'super_string'.

Yep that's true it does. But, you know, that's what I'm writing code for --
strings of chars. I don't really need the particular code I'm writing to
handle every possible type in the world -- just strings of chars. If you
aren't processing strings, then don't use super_string. Pavol and John have
taken care of all the generic cases. I'm reducing things down to the common
and frequent thing that I need to do. And the thing is, there's still nothing
stopping me from writing

    super_string s(...);
    some_free_function_algorithm_here(s, ...);

So what have I lost? Nothing. I've gained cleaner, clearer code for the
things I do every day -- code I can explain to any programmer. There isn't a
single novel algorithm or function in super_string -- I've just optimized the
generic code for the common cases I need by wrapping up a couple of existing
Boost libraries.

> The 'Range' and 'Sequence' abstractions will disappear.
> How does this look? :-)
> replace_all(out(s1), in(s2), in(s3));

Better, but it's still ugly in comparison. I could give the first one to just
about any programmer (even non-c++) and they would get it. With your example
I'm sure lots of programmers will be scratching there heads. They'll be
distracted by the 'in' and 'out'. I certainly am.


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