On Mon, Dec 10, 2012 at 5:33 AM, Doug McIlroy
Matlab exploits them heavily (though represented as doubles).
Not sure what you are referring to
I had in mind Matlab's frequent use of a Boolean array as a characteristic function describing some property of the elements of another array. Such arrays are used to control other array operations. In this usage, the characteristic array may be optimized out of existense, but it fosters higher-level thinking and concise code.
In which case it goes back to APL's compress operator ie 1960. http://www.aplusdev.org/APlusRefV2_8.html#HEADING179 Heres a session that demonstrates A+ Copyright (c) 1990-2008 Morgan Stanley. All rights reserved. This version is Release 4.22 a ← 1 2 3 4 5 b ← 1 0 1 1 0 b/a 1 3 4 b ← 1 0 2 1 0 b/a 1 3 3 4 -- http://www.the-magus.in http://blog.languager.org