newRPL: Named subroutines proposal

[Claudio L.]

(10-15-2015 01:33 AM)Claudio L. Wrote:  In newRPL, the trailing dot was used to indicate numbers that want to be operated upon immediately (which I call approximated). This could be extended to commands and variables for example, to try to do what you suggest.
For example 'SIN(X)' would only evaluate X when you EVAL the expression, not when you enter it. But perhaps you could write 'SIN(X.)' to indicate you want X replaced immediately, and you'd see on the stack 'SIN(pi/2)' assuming 'pi/2' is the contents of X, and this could be recursive, if the contents is 'pi./2' then pi would be replaced immediately.

This thread

http://www.hpmuseum.org/forum/thread-4997.html

Seems to reinforce the idea that approx. Vs. Exact numbers (and eventually variables) needs to be indicated by the user. In existing systems the choice is made for you: if the number is integer is treated as exact and if it's real is approximated. I think the trailing dot in numbers actually improves on this, as you can have the CAS use reals as exact as well. For variable evaluation I think it will be a similar improvement, so I'm planning to move forward with this.