On 5/15/21 4:25 AM, Chris Piker wrote:
> But, loops are bad.
I agree with Adam here. Although most of my recent code gravitates
towards long range expressions, I use 'foreach' (even 'for') when I
think it makes code more readable.
> Is there some obvious trick or way of looking at the problem that I'm
> missing?
The following are idioms that I use:
* The range is part of the type:
struct MyType(R) {
R myRange;
}
* If the type is too complicated as in your examples:
struct MyType(R) {
R myRange;
}
auto makeMyType(X, Y)(/* ... */) {
auto myArg = foo!X.bar!Y.etc;
return MyType!(typeof(myArg))(myArg);
}
* If my type can't be templated:
struct MyType {
alias MyRange = typeof(makeMyArg());
MyRange myRange;
}
// For the alias to work above, all parameters of this
// function must have default values so that the typeof
// expression is as convenient as above.
auto makeMyArg(X, Y)(X x = X.init, Y y = Y.init) {
// Then, you can put some condition checks here if
// X.init and Y.init are invalid values for your
// program.
return foo!X.bar!Y.etc;
}
I think that's all really.
And yes, sometimes there are confusing error messages but the compiler
is always right. :)
Ali
