Please do submit a PR for MapSet.is_member. Since then, we have added map related guards to Kernel, which also do duplicate existing functions in Map, So I think some of my original concerns are no longer relevant. There is also no need to deprecate any of the existing functions.
On Sat, Mar 2, 2024 at 00:30 Christopher Keele <christheke...@gmail.com> wrote: > MapSets are *very* useful constant time data structures; and I keep on > finding myself wishing there was a future-proof approved way to use them in > guards. Consider this my +1. > > I believe eksperimental's original rationale still holds: > > 1. :erlang.is_map_key/2, as well as :erlang.map_get/2, are awkward to use > guards (as of writing, by design, to encourage destructuring) > 2. a MapSet's .map is a private field and should not be > accessed/destructured directly (see: various pain points when the internal > implementation of Range fields changed) > > I'd like to re-open a proposal for a guard-safe MapSet.is_member/2, with > the implementation: > > defmodule MapSet do > defguard is_member(map_set, value) > when is_struct(map_set, __MODULE__) and > :erlang.is_map_key(value, map_set.map) > end > > This would bring the core conceit of MapSets (constant-time set > membership) into where they are very valuable (constant-time guard > operations for pattern matching against function heads). > > I am not convinced that deprecating MapSet.member?/2 adds much value if it > would force developers to require MapSet before using its core > functionality, so I'm content having a bit of duplication. Similarly, > checking the size of a MapSet is less core to its utility, and again I > wouldn't want to developers to have to require the module just to check the > size—so I'm proposing that addition. Just the single guard! > On Thursday, December 24, 2020 at 1:37:40 AM UTC-6 José Valim wrote: > >> Because if I have a MapSet, I would prefer to call MapSet API to make the >> intent clearer. >> >> On Thu, Dec 24, 2020 at 4:48 AM eksperimental <eksper...@autistici.org> >> wrote: >> >>> On Mon, 21 Dec 2020 22:37:53 -0500 >>> eksperimental <eksper...@autistici.org> wrote: >>> >>> > Hi list, >>> > I would like to propose to convert two existing functions to guards in >>> > the MapSet module. >>> > >>> > 1. Is MapSet.size/1. I found myself not being able to use this >>> > function in guards, and having to port my code, unless I want to get >>> > into the bad habit of reading the internal structure of the struct >>> > which is an opaque type. >>> > This guard can be implemented with :erlang.map_get/2 >>> > >>> > 2. Deprecate MapSet.member?/2 in favor of MapSet.is_member/2 >>> > >>> > Thank you for reading >>> > >>> >>> Actually, why are we having MapSet.member?/2 when we have >>> Enum.member?/2. It is redudant. >> >> >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "elixir-lang-core" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to elixir-lang-co...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/elixir-lang-core/5fe40f76.1c69fb81.f8161.5ba3SMTPIN_ADDED_MISSING%40gmr-mx.google.com >>> . >>> >> -- > You received this message because you are subscribed to the Google Groups > "elixir-lang-core" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to elixir-lang-core+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elixir-lang-core/93cec4b9-526c-48a9-9bb6-94c06c74827bn%40googlegroups.com > <https://groups.google.com/d/msgid/elixir-lang-core/93cec4b9-526c-48a9-9bb6-94c06c74827bn%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. To unsubscribe from this group and stop receiving emails from it, send an email to elixir-lang-core+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4LD7gfEj2kySpfoSebNQp4-tBPXseDZNs9VAR8UfaPVQQ%40mail.gmail.com.
