On 10-mar-10, at 23:52, bearophile wrote:
Fawzi Mohamed:
If you look at the allocations needed for a toString, one sees the
allocation of a lot of small strings, alloacation for the
concatenation
of a couple of the small strings, then again for the larger blocks
until you get the final string.
A possible idea is to replace the current object.toString:
string toString();
With something vaguely like (keeping it simple):
string toString(void delegate(string) sink=null);
If called with no arguments the toString has to output a string, as
now.
If called with a sink that is not null, the toString can choose to
use it for the output and return an empty string, or ignore it and
return a string.
The caller can give a sink or not. But even if gives a sink it has
to test if the return value is an nonempty string, because the
toString is free to ignore the given sink.
[Extra: if toString both returns a nonempty string and gives
something to the sink, then the caller can use a nice silver coin to
choose among the two.]
this makes the implementation of toString more complicated, I have
void desc(void delegate(string))
and actually normally I mixin serialization and then mixin a template
(printOut) that implements desc using Json serialization, and toString
by collecting desc into a GrowableArray...
