Thanks to you both. I'm happy to have it confirmed as a no-op. Integer-boolean conversion, not needed here though perhaps in an earlier version of J, or indeed APL. That makes sense.
Cheers. On Wed, Feb 3, 2016 at 10:35 AM, Roger Hui <[email protected]> wrote: > I don't think it's that significant. In 1=?s$2 the 1= is a no-op. It's > there possibly because: > > - Muscle memory. In APL, in 1-origin, the 1= is needed to convert integers > to booleans. > - There's a lot of cut-and-paste in making the test scripts. Could have > been cut and pasted from somewhere else. > - Phrase of the moon. > > If anyone knows, I should know (I wrote the test script), and I don't > know/remember. > > > > On Tue, Feb 2, 2016 at 2:22 PM, Matthew Baulch <[email protected]> > wrote: > > > I've been reading the tests in the J engine source. Have learned quite a > > bit while doing so! Anyhow, I've become perplexed by one particular line. > > > > In the 'Boolean' section of the tests for 'x i. y' (test/gi.ijs), a > random > > table is constructed with > > > > a=:1=?10 5$2 > > > > > > My question is, why is a=:?10 5$2 not sufficient. Can someone tell be if > > these are equivalent, or if not, why? > > > > > > I should note that 1=?70$3 is used in the same file, and it's clear to me > > that '1=' affects the probability distribution for rolls over a domain > > larger than two, so it serves a purpose. > > > > > > Sorry if source would have been a better forum for this post. I'm not > sure > > if this is an error in the test, or simply a deficiency in my > understanding > > of J. > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
