Re: PATCH: Speed up direct string concatenation by 20+%!

Robin Becker wrote:
Larry Hastings wrote:
______
THE PATCH

The core concept: adding two strings together no longer returns a pure
"string" object. Instead, it returns a "string concatenation" object
which holds references to the two strings but does not actually
concatenate
them... yet. The strings are concatenated only when someone requests
the
string's value, at which point it allocates all the space it needs and
renders the concatenated string all at once.

More to the point, if you add multiple strings together (a + b + c),
it *doesn't* compute the intermediate strings (a + b).

Upsides to this approach:
........

wouldn't this approach apply to other additions eg list+list seq+seq etc
etc.

no, I think it depends on strings being immutable. If you do list1 +
list2 that way and list1 is mutated then the resulting list would be
changed too.

I suppose the utility of such an approach depends on the frequency with
which multiple strings/lists/sequences etc are added together in real
code.

I think there are quite a lot of string additions around, it's just that
people get told to use join all the time, so they are not written using "+".

Cheers,

Carl Friedrich

.

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