I agree that we should have wildcard patterns. I also think that array elisions are a non-solution, because you need a magnifier to read or count them, and they square oddly with optional commas in the end.
/Andreas On 29 April 2015 at 13:47, Elie Rotenberg <[email protected]> wrote: > Wow, thanks. I feel dumb for asking :D > > On Wed, Apr 29, 2015 at 1:43 PM, Sebastian McKenzie <[email protected]> > wrote: > >> The binding identifiers are optional. You can do what you want already >> with: >> >> const lastOfThree = ([,, third]) => { >> return third; >> } >> >> >> >> >> On Wed, Apr 29, 2015 at 12:40 PM, Elie Rotenberg <[email protected]> >> wrote: >> >>> Using array destructuring assignment and constraining linting rules, I >>> often find myself having to chose names for bindings I don't intent on >>> using. I usually end up using a conventional ignore name, such as _ignore, >>> which I "void" to shut up the linter without adding exceptions. Besides the >>> linting problem (which can be solved by refining the linting rules), it's >>> still a conceptually useless binding. >>> >>> Here's a contrived example: >>> >>> const lastOfThree = ([first, second, third]) => third; >>> >>> Which I usually end up rewriting: >>> >>> const lastOfThree = ([_ignore1, _ignore2, third]) => { >>> void _ignore1; >>> void _ignore2; >>> return third; >>> } >>> >>> This problem doesn't exist when using objects, since only the fields >>> specified on the LHS are bound. >>> >>> I realize the bigger topic behind non-binding match is refutable pattern >>> matching, as per >>> http://wiki.ecmascript.org/doku.php?id=strawman:pattern_matching, but >>> being able to dismiss a matched (or unmatched) value from a destructuring >>> assignment seems a very often desirable feature when programming in a >>> functional style (eg. working with lists represented as 2-element arrays). >>> Most functional-style languages have a non-binding matching feature. >>> >>> This topic has been discussed in the following topics: >>> - https://esdiscuss.org/topic/conditional-catch >>> - https://esdiscuss.org/notes/2014-07-30 >>> - https://esdiscuss.org/topic/conditional-catch-clause >>> >>> Does anyone else feel the need for a specific means of dismissing a >>> binding from a destructuring assignment? Is pattern matching still on >>> discussion? >>> >>> Regards, >>> >> >> > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > >
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