DMD 1.038 and 2.022 releases

[John Reimer]

Hello Sean,

> bearophile wrote:
> 
>> Walter Bright:
>> 
>>> Excess isn't the problem, I want to see if import cycles is.
>>> 
>> Generally all the modules in my dlibs import each other. This is
>> nearly unavoidable, if a module contains string functions, and
>> another one contains math stuff, the string module will want to use
>> some math stuff and the math module may need string representations
>> and processing. In the D specs I haven't seen an advice to not use
>> cyclic imports, so I don't want such compiler flag, I prefer a
>> compiler able to manage such cyclic imports efficiently.
>> 
> Cyclic imports are a bad idea in general because of the impact they
> have on verifiability (unit testing).  But as you say, sometimes
> they're unavoidable.
> 
> Sean
> 


I'd going to wager that they are /often/ unavoidable, especially in ported 
projects from other languages that have either no concept or a different 
concept of modules/packages.

DWT is perhaps the single worse example of cyclic imports.  I'm not sure 
how the design could have been improved in Java's SWT.  All it takes is the 
need to reference one symbol in each module (because each object apparently 
needs to just "know" about the other) to create a cyclic import issue in D.  

Static initialization has also been a problem in DWT such that a few significant 
workarounds were necessary.

I agree that the interdepencies should be avoided in all new projects designed 
specifically for D.  I'm just not sure what the solution would be for the 
great mass of ported software.

-JJR