Groups > comp.soft-sys.math.mathematica > #1998

HoldAll/HoldRest // updated

From	"Scot T. Martin" <smartin@seas.harvard.edu>
Newsgroups	comp.soft-sys.math.mathematica
Subject	HoldAll/HoldRest // updated
Date	2011-04-29 11:34 +0000
Organization	Steven M. Christensen and Associates, Inc and MathTensor, Inc.
Message-ID	<ipe7o9$r36$1@smc.vnet.net> (permalink)

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Fixing small but important typos from email of a few minutes ago.... and re-posting:



Some kind of issue going on here between the interactions of HoldAll and HoldRest of ValueQ[...], If[...], and Function[...]. Anyone know the solution so that Out[3] results in 5?



In[1]:= valueQ = If[ValueQ[#], #, False] &



Out[1]= If[ValueQ[#1], #1, False] &



In[2]:= x = 5



Out[2]= 5



In[3]:= valueQ[x]



Out[3]= False



In[4]:= If[ValueQ[x], x, False]



Out[4]= 5

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HoldAll/HoldRest // updated "Scot T. Martin" <smartin@seas.harvard.edu> - 2011-04-29 11:34 +0000

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