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From: Sam Halliday <sam.halliday@gmail.com>
To: help-gnu-emacs@gnu.org
Subject: destructuring-bind for subset of plist
Date: Wed, 25 May 2016 14:23:12 -0700 (PDT)	[thread overview]
Message-ID: <06aeb16e-843c-4964-bf31-09fe16e4488d@googlegroups.com> (raw)

Hi all,

This causes an error

  (cl-destructuring-bind
      (&key a b)
      '(:a "foo" :b 13 :c "bar")
    (list a b))

because the :c key/value is not handled in the pattern match.

Often I find myself wanting to extract some subset of keys/values from a plist, but cl-destructuring-bind isn't appropriate because of this limitation.

Is there a way to make cl-destructuring-bind simply ignore unmatched keys in the EXPR? I'm not sure what the official common lisp behaviour is supposed to be here, is the error in the spec?

Note that the dash library has some support for a similar destructuring with -let, but that requires some boilerplate to assign a symbol to each key.

Best regards,
Sam


             reply	other threads:[~2016-05-25 21:23 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-25 21:23 Sam Halliday [this message]
2016-05-26  1:30 ` destructuring-bind for subset of plist Barry Margolin

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