> De: "John Rose" <john.r.r...@oracle.com> > À: "Daniel Heidinga" <daniel_heidi...@ca.ibm.com> > Cc: "amber-spec-experts" <amber-spec-experts@openjdk.java.net> > Envoyé: Mardi 14 Janvier 2020 23:49:54 > Objet: Re: [records] updates for Preview 9. hashCode
> On Jan 14, 2020, at 6:49 AM, Daniel Heidinga < [ > mailto:daniel_heidi...@ca.ibm.com | daniel_heidi...@ca.ibm.com ] > wrote: >> This gets a +1 from me. The format is clear - explained so it's easy >> to understand what the parts mean - and explicit that it may change. >> We can't ever stop users from parsing #toString but this is explicit >> that's a bad idea for them to do so. > OK, so I’ve updated the proposed doc change along those lines. > [ http://cr.openjdk.java.net/~jrose/draft/record-contract | > http://cr.openjdk.java.net/~jrose/draft/record-contract ] > (Previous versions are …/record-contract.{00,01}.) > I adapted the javadoc from AbstractMap::toString, and > then added some sample code, just for grins. It would be > fine to delete the sample code. > * @implNote > * The implicitly provided implementation returns a string which begins > * with the unqualified name of the record class and is immediately > * followed by a list of components, in declaration order, > * enclosed in square brackets ({@code "[]"}). Adjacent components > * are separated by the characters {@code ", "} (comma and space). > * Each component is rendered as the name followed by an equals sign > * ({@code "="}) followed by a string representing the associated value. > The language is intentionally vague about what is “a string representing > the associated value”. There are comments in the prototype that mention > maybe adding quotes to some values (Strings). So I left that open. This is almost OT but it's a question I was asked for twice, what is the rational to use the angle bracket instead of the parenthesis ? Using parenthesis makes the syntax and the returns of toString() more close together, the one mirroring the other. My answer is that a record is a named tuple, so the closest approximation we have is a list of entries (Map.Entry) hence the syntax. > — John Rémi
