Michael Heerdegen schrieb am Di., 7. Nov. 2017 um 14:29 Uhr: > Noam Postavsky writes: > > > Drew Adams writes: > > > > > Any news on this? There is no general, abstract > > > solution proposed, so far, to meet the needs met > > > by the specific alist <-> hash-table code I sent. > > > > Did you have any comments for my proposal in #29? > > That's clever. > > OTOH I'm not convinced that `map-into' is a good abstraction. Every > goal type might have an individual set of useful parameters, especially > when we want to add support for other map types in the future. Our > choice now to unite those in one conversion interface function might > result in quite a mess later. > I don't think a unified conversion interface is that important. The various structures used for mappings are just too different. For example, alists and plists aren't real types, they are only defined by their usage. Hash tables, on the other hand, are real types, with a per-object comparison function, a non-nil empty value, etc. These two kinds of objects are just too different to treat uniformly. Also, in most cases it is statically known which kinds of objects are involved, so a generic function that dynamically selects on the type of object isn't that useful. How about adding some simple conversion functions to subr.el such as (defun alist-to-hashtable (alist &rest keys) ...) (defun hashtable-to-alist (hashtable) ...)