__traits for checking if a type is dynamic array (slice)
https://forum.dlang.org/post/ptgud7$16f6$1...@digitalmars.com On Monday, 26 November 2018 at 14:02:15 UTC, Andrei Alexandrescu wrote: On 11/26/18 4:04 AM, Per Nordlöw wrote: Why is there no - __traits(isArray, T) alongside - __traits(isStaticArray, T) and - __traits(isAssociativeArray, T) Thanks for bringing this to my attention, Per. The core idea is to have __traits "primitive and ugly" and std.traits "convenient and nice". From that viewpoint, if isArray can be implemented as a library feature using primitives provided by traits, there is no need for making it. when dmd already has `ENUMTY.Tarray` alongside - ENUMTY.Tsarray and - ENUMTY.Taarray Justifying the feature by means of a detail in the compiler implementation is definitely undesirable. and std.traits already has a wrapper for this at https://dlang.org/phobos/std_traits.html#isDynamicArray ? If the wrapper works well, use it and move on. Thanks, Andrei I am in disagreement. The is expressions are complicated both for a developer and the compiler. If one promotes a wrapper template that shows just that the way of expressing it is too complicated. low level tools should be simple, because if they are not simple they can't be low-level.
Re: __traits for checking if a type is dynamic array (slice)
On 11/26/18 4:04 AM, Per Nordlöw wrote: Why is there no - __traits(isArray, T) alongside - __traits(isStaticArray, T) and - __traits(isAssociativeArray, T) Thanks for bringing this to my attention, Per. The core idea is to have __traits "primitive and ugly" and std.traits "convenient and nice". From that viewpoint, if isArray can be implemented as a library feature using primitives provided by traits, there is no need for making it. when dmd already has `ENUMTY.Tarray` alongside - ENUMTY.Tsarray and - ENUMTY.Taarray Justifying the feature by means of a detail in the compiler implementation is definitely undesirable. and std.traits already has a wrapper for this at https://dlang.org/phobos/std_traits.html#isDynamicArray ? If the wrapper works well, use it and move on. Thanks, Andrei
Re: __traits for checking if a type is dynamic array (slice)
On Monday, 26 November 2018 at 10:53:25 UTC, Eduard Staniloiu wrote: I would like to see this in the compiler traits :D https://github.com/dlang/dmd/pull/9014
Re: __traits for checking if a type is dynamic array (slice)
On Monday, 26 November 2018 at 09:28:37 UTC, Basile B. wrote: On Monday, 26 November 2018 at 09:04:25 UTC, Per Nordlöw wrote: Why is there no - __traits(isArray, T) alongside - __traits(isStaticArray, T) and - __traits(isAssociativeArray, T) when dmd already has `ENUMTY.Tarray` alongside - ENUMTY.Tsarray and - ENUMTY.Taarray and std.traits already has a wrapper for this at https://dlang.org/phobos/std_traits.html#isDynamicArray ? Should we add this new builtin trait and use it in std.traits.isDynamicArray? If so, should we call it - __traits(isDynamicArray) or - __traits(isArray) or - __traits(isArraySlice) or - __traits(isSlice) or something else? Yeah maybe just try, although i see some alias this implication in the current std.traits implementation. Adding a new trait is rarely a big deal as far as i could see in the past (i.e no big never endings discussions). This would be a nice addition, imho. As Basile B is saying, there is quite a bit of work done for the `isDynamicArray` implementation. If you have the time to drill down from https://github.com/dlang/phobos/blob/master/std/traits.d#L6618 I was expecting the `isArray` check to be something like `enum isArray(T) = is(T == U[], U)` I would like to see this in the compiler traits :D
Re: __traits for checking if a type is dynamic array (slice)
On Monday, 26 November 2018 at 09:04:25 UTC, Per Nordlöw wrote: Why is there no - __traits(isArray, T) alongside - __traits(isStaticArray, T) and - __traits(isAssociativeArray, T) when dmd already has `ENUMTY.Tarray` alongside - ENUMTY.Tsarray and - ENUMTY.Taarray and std.traits already has a wrapper for this at https://dlang.org/phobos/std_traits.html#isDynamicArray ? Should we add this new builtin trait and use it in std.traits.isDynamicArray? If so, should we call it - __traits(isDynamicArray) or - __traits(isArray) or - __traits(isArraySlice) or - __traits(isSlice) or something else? Yeah maybe just try, although i see some alias this implication in the current std.traits implementation. Adding a new trait is rarely a big deal as far as i could see in the past (i.e no big never endings discussions).
__traits for checking if a type is dynamic array (slice)
Why is there no - __traits(isArray, T) alongside - __traits(isStaticArray, T) and - __traits(isAssociativeArray, T) when dmd already has `ENUMTY.Tarray` alongside - ENUMTY.Tsarray and - ENUMTY.Taarray and std.traits already has a wrapper for this at https://dlang.org/phobos/std_traits.html#isDynamicArray ? Should we add this new builtin trait and use it in std.traits.isDynamicArray? If so, should we call it - __traits(isDynamicArray) or - __traits(isArray) or - __traits(isArraySlice) or - __traits(isSlice) or something else?
