Re: Java moves to copying for substrings

[bearophile]

Jesse Phillips:

Somewhat interesting, Java has chosen to make substring result 
in a copy of the string data rather than returning a window of 
the underlying chars.

I presume in Java slices weren't very common, unlike in D. So I 
think this is the right design choice for Java (also because 
those Java strings are too much large, four instance fields), but 
D is better designed as it is.

On the other hand the idea of putting the hash code inside the 
string in D was not discussed enough :-)


From the discussion, Dmd associative arrays were designed like 
this:

In Java 8 an improved solution devised by Doug Lea is used. In 
this solution colliding but Comparable Map keys are placed in a 
tree rather than a linked listed. Performance degenerates to 
O(log n) for the collisions but this is usually small unless 
someone is creating keys which intentionally collide or has a 
very, very bad hashcode implementation, ie. "return 3".<

I am reminded of a denial of service attack that used 
intentionally colliding request field names/values to attack web 
servers and bringing down servers to their knees.<

Bye,
bearophile