Re: Releasing several Holds simultaneously
- To: mathgroup at smc.vnet.net
- Subject: [mg82285] Re: Releasing several Holds simultaneously
- From: Szabolcs Horvát <szhorvat at gmail.com>
- Date: Wed, 17 Oct 2007 03:53:28 -0400 (EDT)
- References: <ff1po5$90n$1@smc.vnet.net>
Andrew Moylan wrote: > Hold[a := Hold[1]] > > How can I release both of these Holds (and thus execute a:=1) > simultaneously? > > ReleaseHold[%] doesn't work; it evaluates a := Hold[1] before the other hold > is removed. > > % /. Hold[x_]:>x does the same thing, because /. only matches once per part. This should work for releasing all Holds in expr: Replace[expr, Hold[e___] :> e, {0, Infinity}, Heads -> True] -- Szabolcs