2x 3r4 2 3r4 2x 3.3r4 |ill-formed number 2 3.3r4 2 0.825 Looks like it gets it's mouth set for integer once it sees the x but then gets the error when it encounters the decimal point. Seems to handle x and r mixed just fine.
On Wed, Feb 18, 2009 at 2:12 PM, Dan Bron <[email protected]> wrote: > Roger wrote: > > We are talking about the rules for numeric vector constants > > It would be helpful if these rules were spelled out. The rules for an > individual numeric constant are spelled out explicitly at > http://www.jsoftware.com/help/dictionary/dcons.htm . However, the > interpretation of those rules changes depending on the larger vector in > which the individual constant is embedded. > > This can be amusing [1], or confusing, as in this thread. It doesn't > bother me personally, per se; my interest in seeing the rules spelled out > is so I can create a J model of J's numeric constant interpreter (part of > my ongoing project to reimplement J in J). > > Right now, I could write the interpreter according to Constants, such that: > > numeric '1x1 1p1 16bcdef' > (1 * ^1), (1 * o.1), (16 #. '0123456789abcdefghijklmnopqrstuvwxyz' > i. > 'cdef') > > but since the interpretation changes with context in an unspecified manner, > the emulation wouldn't be faithful, which thwarts my purpose. > > -Dan > > [1] http://www.jsoftware.com/pipermail/programming/2006-July/002615.html > > > PS: There is a bit more information available on J's numeric constants, > for those who're interested: > > http://www.jsoftware.com/jwiki/Guides/Constants > > and some observations I wrote up a while back: > > http://www.jsoftware.com/pipermail/general/2006-June/027263.html > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
