DIP60: @nogc attribute

[bearophile via Digitalmars-d]

Walter Bright:

> http://wiki.dlang.org/DIP60

Given the current strong constraints in the directions of D 
design, I like it.

But in DIPs I suggest to also write a list of the advantages of a 
proposal, and a list of all the disadvantages.

In this ER I suggested a @noheap, that is meant to also forbid 
the C memory allocation functions:
https://issues.dlang.org/show_bug.cgi?id=5219
But I guess there is no reliable way to catch those function 
calls too?
If the discussion is against @noheap then I'll close that ER as 
obsolete.

With @nogc D has most of the basic function effects covered. One 
missing effect that D is not yet putting under control is 
nontermination; to annotate functions that can not loop forever 
and never return (like a function with an infinite loop inside, 
etc). But for the kind of programs written in D, I presume this 
effect is not yet important enough to deserve an annotation like 
@terminates.

There is a language studied by Microsoft that faces the problem 
of effects algebra in a more discipled and high-level way. I 
don't know how much this can help D at its current development 
stage:
http://research.microsoft.com/en-us/projects/koka/
But in general reading research papers is useful to get in a good 
mindframe.
In Koka language the functions that can not terminate are 
annotated with "div", that means "divergence". But Koka has a 
good effect inference.

Bye,
bearophile