digitalmars.D - nogc hash
- Marco Leise (7/7) Sep 09 2016 What is the way forward with @nogc and hash tables?
- Guillaume Piolat (2/4) Sep 09 2016 It is with http://code.dlang.org/packages/emsi_containers
- Marco Leise (10/15) Sep 09 2016 It does not /allocate/ with the GC, but the methods are
- Guillaume Piolat (4/10) Sep 09 2016 But they are template functions.
- Basile B. (6/17) Sep 09 2016 Strangely you seemed to know, 1 month ago, about the annotation
- Guillaume Piolat (3/7) Sep 09 2016 Yes. But I instantly forget about it since I've implemented a
- Marco Leise (17/29) Sep 09 2016 Sorry, I didn't want to talk about the lack of attribute
- Guillaume Piolat (4/13) Sep 09 2016 Yeah it wouldn't be far-fetched to make toHash() @nogc nothrow.
What is the way forward with nogc and hash tables? At the moment it is - AFAICT - not possible to insert an element into a hash table in nogc code. Aggregate types work since you can always implement a nogc toHash and look for that, but other types don't. Or do I miss something? -- Marco
Sep 09 2016
On Friday, 9 September 2016 at 10:16:09 UTC, Marco Leise wrote:it is - AFAICT - not possible to insert an element into a hash table in nogc code.It is with http://code.dlang.org/packages/emsi_containers
Sep 09 2016
Am Fri, 09 Sep 2016 10:52:54 +0000 schrieb Guillaume Piolat <first.last gmail.com>:On Friday, 9 September 2016 at 10:16:09 UTC, Marco Leise wrote:It does not /allocate/ with the GC, but the methods are not /annotated/ nogc, e.g. insert(): https://github.com/economicmodeling/containers/blob/master/src/containers/hashmap.d#L338 It's plain simple not possible out of the box* at the moment. * writing your own hash function that covers every type is NOT "out of the box" :p -- Marcoit is - AFAICT - not possible to insert an element into a hash table in nogc code.It is with http://code.dlang.org/packages/emsi_containers
Sep 09 2016
On Friday, 9 September 2016 at 11:16:19 UTC, Marco Leise wrote:It does not /allocate/ with the GC, but the methods are not /annotated/ nogc, e.g. insert(): https://github.com/economicmodeling/containers/blob/master/src/containers/hashmap.d#L338 It's plain simple not possible out of the box* at the moment. * writing your own hash function that covers every type is NOT "out of the box" :pBut they are template functions. Maybe this is a case of https://p0nce.github.io/d-idioms/#Automatic-attribute-inference-fo -function-templates then?
Sep 09 2016
On Friday, 9 September 2016 at 11:35:58 UTC, Guillaume Piolat wrote:On Friday, 9 September 2016 at 11:16:19 UTC, Marco Leise wrote:Strangely you seemed to know, 1 month ago, about the annotation problem ! Wasn't this you "ponce" that opened this Q https://github.com/economicmodeling/containers/issues/60 ?It does not /allocate/ with the GC, but the methods are not /annotated/ nogc, e.g. insert(): https://github.com/economicmodeling/containers/blob/master/src/containers/hashmap.d#L338 It's plain simple not possible out of the box* at the moment. * writing your own hash function that covers every type is NOT "out of the box" :pBut they are template functions. Maybe this is a case of https://p0nce.github.io/d-idioms/#Automatic-attribute-inference-fo -function-templates then?
Sep 09 2016
Guillaume Piolat <first.last gmail.com> On Friday, 9 September 2016 at 12:31:04 UTC, Basile B. wrote:Strangely you seemed to know, 1 month ago, about the annotation problem ! Wasn't this you "ponce" that opened this Q https://github.com/economicmodeling/containers/issues/60 ?Yes. But I instantly forget about it since I've implemented a linear search instead since.
Sep 09 2016
Am Fri, 09 Sep 2016 11:35:58 +0000 schrieb Guillaume Piolat <first.last gmail.com>:On Friday, 9 September 2016 at 11:16:19 UTC, Marco Leise wrote:Sorry, I didn't want to talk about the lack of attribute inference for non-templated functions inside templates :p. Yes, that's why some of the methods in EMSI containers are annotated and I'm aware of that. The point is that TypeInfo_*.getHash() cannot be nogc, because a class or struct may implement a not- nogc toHash(). (Where I may add, that e.g. TypeInfo_Pointer.getHash() *could* be nogc, since all it returns is `cast(size_t)cast(void*)p`). The alternatives in core.internal.hash are supposed to be CTFE-able and albeit bytesHash itself does not seem to use the GC, the wrapper functions for different types may. And that is why nogc hash table implementations don't fly at the moment. -- MarcoIt does not /allocate/ with the GC, but the methods are not /annotated/ nogc, e.g. insert(): https://github.com/economicmodeling/containers/blob/master/src/containers/hashmap.d#L338 It's plain simple not possible out of the box* at the moment. * writing your own hash function that covers every type is NOT "out of the box" :pBut they are template functions. Maybe this is a case of https://p0nce.github.io/d-idioms/#Automatic-attribute-inference-fo -function-templates then?
Sep 09 2016
On Friday, 9 September 2016 at 12:31:34 UTC, Marco Leise wrote:The point is that TypeInfo_*.getHash() cannot be nogc, because a class or struct may implement a not- nogc toHash(). (Where I may add, that e.g. TypeInfo_Pointer.getHash() *could* be nogc, since all it returns is `cast(size_t)cast(void*)p`). The alternatives in core.internal.hash are supposed to be CTFE-able and albeit bytesHash itself does not seem to use the GC, the wrapper functions for different types may. And that is why nogc hash table implementations don't fly at the moment.Yeah it wouldn't be far-fetched to make toHash() nogc nothrow. A hash-table that allocates on lookup would negate any speed-advantage anyway.
Sep 09 2016