• Mark (4/4) Feb 24 2021 Is there a way to obtain a list, at compile-time, of all the
• SealabJaster (11/15) Feb 24 2021 I don't believe that there's any built-in way, as that'd mean
• SealabJaster (4/5) Feb 24 2021 Just realised that can include duplicates, but there's
• Dennis (4/7) Feb 24 2021 No, since this is not known at compile-time.
• James Blachly (6/11) Feb 25 2021 Crazy idea:
• Arafel (11/24) Feb 25 2021 You'd hit a very big wall with separate compilation unless you can

Mark <smarksc gmail.com> writes:

Is there a way to obtain a list, at compile-time, of all the 
exception types that a function might throw (directly or through 
a call to another function)?

Thanks.

SealabJaster <sealabjaster gmail.com> writes:

On Wednesday, 24 February 2021 at 19:38:53 UTC, Mark wrote:
 Is there a way to obtain a list, at compile-time, of all the 
 exception types that a function might throw (directly or 
 through a call to another function)?

 Thanks.

I don't believe that there's any built-in way, as that'd mean 
that functions would have to define what they throw as part of 
their signature (like in Java).

But you can semi-emulate it with metaprogramming, it's just that 
you'll have to manually keep all the information up to date.

Here's an example: https://run.dlang.io/is/UUHumO

Which supports saying what a function directly throws 
(` Throws`), and also saying what functions it calls that may 
also throw well-defined exceptions (` ThrowsInclude`), and 
results in `(Exception, MyExcept)`

SealabJaster <sealabjaster gmail.com> writes:

On Wednesday, 24 February 2021 at 19:58:41 UTC, SealabJaster 
wrote:
 ...

Just realised that can include duplicates, but there's 
std.meta.NoDuplicates to solve that.

Dennis <dkorpel gmail.com> writes:

On Wednesday, 24 February 2021 at 19:38:53 UTC, Mark wrote:
 Is there a way to obtain a list, at compile-time, of all the 
 exception types that a function might throw (directly or 
 through a call to another function)?

No, since this is not known at compile-time.

See: 
https://forum.dlang.org/post/qnarroejixxtqxjiwvhy forum.dlang.org

James Blachly <james.blachly gmail.com> writes:

On 2/24/21 2:38 PM, Mark wrote:
 Is there a way to obtain a list, at compile-time, of all the exception 
 types that a function might throw (directly or through a call to another 
 function)?
 
 Thanks.

Crazy idea:

Could a program import its own source file as a string (`string source = 
import('thisfile.d')`) and `-J<path>` , then use a lexer/parser to 
generate AST of the source code and extract exceptions potentially 
thrown by given functions -- all at compile  time?

Arafel <er.krali gmail.com> writes:

You'd hit a very big wall with separate compilation unless you can 
inspect all the code, and know where to find it.

But you'd have a problem, for instance, if you are writing a plugin (.so 
/ DLL) for a product for which you only have .di files.

Or even worse the other way round: if you want to allow people to write 
plugins for your product, you can't know what they'll throw, even if 
they have your code, unless you enforce a `nothrow` interface.

But I guess that if you're not doing any of this, it should be 
possible... although I'd still do it as a separate pre-compilation step, 
so it could be cached.

On 26/2/21 3:21, James Blachly wrote:
 On 2/24/21 2:38 PM, Mark wrote:
 Is there a way to obtain a list, at compile-time, of all the exception 
 types that a function might throw (directly or through a call to 
 another function)?

 Thanks.

 
 Crazy idea:
 
 Could a program import its own source file as a string (`string source = 
 import('thisfile.d')`) and `-J<path>` , then use a lexer/parser to 
 generate AST of the source code and extract exceptions potentially 
 thrown by given functions -- all at compile  time?