(Curious) behavior of Reap
- To: mathgroup at smc.vnet.net
- Subject: [mg129947] (Curious) behavior of Reap
- From: Roger Wilson <rogerhw999 at gmail.com>
- Date: Wed, 27 Feb 2013 23:42:34 -0500 (EST)
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- Delivered-to: l-mathgroup@wolfram.com
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If tags are not specified when collecting results using Reap previously pushed into Sow the results are returned in a list of sublists...
Reap[Sow[1, a]; Sow[2, a]; Sow[3, b];]
{Null, {{1, 2}, {3}}}
If tags are specified the results are returned in nested sublists...
Reap[Sow[1, a]; Sow[2, a]; Sow[3, b];, {a, b}]
{Null, {{{1, 2}}, {{3}}}}
I would have expected no difference in the structure of the results returned.
Is this simply a historical inconsistency in Mathematica or is this behavior intended and if so what purpose does it serve?