newRPL: Alpha demo 0.9 released [UPDATED 2017-10-25]

[The Shadow]

Some suggested extended types:

Vectors as opposed to matrices.

Vectors and matrices that contain symbolics as opposed to those don't.

Vectors and matrices that contain complex numbers as opposed to those that only contain reals.

Algebraics that contain undefined variables (and thus can't be ->NUM'd) as opposed to those that don't. (Alternatively or in addition, algebraics that contain identifiers as opposed to those that only contain numbers and operators.)

Also, I just discovered that '0' counts as non-zero for purposes of IF, but not for NOT. I don't know if this is intended, but it's definitely unexpected.

To clarify, IF '0' THEN 1 ELSE 0 END and IF '0' NOT THEN 1 ELSE 0 END both return 1. You can fix it by doing EVAL or ->NUM on the '0' first, of course, but it's still unexpected. I'm guessing that any algebraic counts as "something"?

Likewise, IF 'X' THEN 1 ELSE 0 END returns 1, while oldRPL gives an undefined name error.

EDIT: I also just discovered that trying to find the inverse of the matrix:

[ [ 0 1 ] [ -1 0 ] ]

gives an 'Undefined result' error. If I then try to invert

[ [ '0' '1' ] [ '-1' '0' ] ]

I get

[ [ '0/0' '0/0'] [ '1' '0' ] ]

which may give some insight as to why this is happening.

EDIT:

I've emailed you two programs in which SAME, or possibly IFERR, is acting very oddly.