Suggestion: Syntactic sugar for Exception handling in D2

[Tomasz Sowiñski]

I like it. Although it's only sugar you're right -- it helps reading a bit. But I would allow (or even require) "try" before a block of code:

if (condition) try {
    ...
} catch (Exception ex) {
    ...
}

Seeing "try" there cuts down on the gray matter needed to understand what it does. And just not to stray too much from the C-family.

Tomek

Ulrik Mikaelsson Wrote:

> One thing I often encounter in D, and other languages, is functions looking something like;
> 
> void myfunc(Obj input)
> {
>    try {
>      do_something(input);
>    } catch (SomeException e) {
>      handle_error(e);
>    }
> }
> 
> While there's no real problem with this code, I have some experience from Ruby, which has added some syntactic sugar regarding this, making all code-blocks a potential "try-clause", if there's a catch-block (or finally).
> 
> In D, it would look something like (and have the exact same semantic meaning of the code above);
> 
> void myfunc(Obj input)
> {
>    do_something(input);
> }
> catch (SomeException e)
> {
>    handle_error(e);
> }
> 
> IMHO, this syntactic addition gives a few advantages;
>   * Makes the code slightly more readable, since the "exceptional" code-paths are clearly separated
>   * Biases me as a programmer to think a little bit more of exactly what exceptions can be raised in a function, improving my code-quality.
>   * When I'm about to write a try-clause, makes me think twice if the code could not be extracted as a separate method instead (if I can only figure a good name for it), also improving readability and code-structure.
> 
> To sum up; while this is purely syntactic sugar, my personal experience from Ruby is that this syntax encourages better coding on my part, which I think would be a good thing to incorporate in D.
> 
> One thing, I'm pondering though, is exactly in what blocks this should be allowed, and what semantics should apply.
>   * Inner anonymous functions? 
>   * If statements?
>   * For-loops? If so, is the try for the entire loop, or per iteration?
>   * How does this relate to the contract-programming-features in D?
> 
> Comments / opinions on this, anyone?