version 13 - []FR

General APL language issues
Post Reply
User avatar
giangiquario
Posts: 46
Joined: Thu Nov 26, 2009 8:55 am
Location: Milano, Italia

version 13 - []FR

Post by giangiquario »

I'd like to know why the new system variable ⎕FR has a workspace scope.
Many other system vars (⎕IO ⎕ML ⎕PP .. )have a namespace scope.

Thank you,
Gianluigi Quario
User avatar
Morten|Dyalog
Posts: 460
Joined: Tue Sep 09, 2008 3:52 pm

Re: version 13 - []FR

Post by Morten|Dyalog »

We were in a lot of doubt as to whether we should allow you to switch floating-point representations AT ALL during a session. The system is not designed to allow "seamless" switching between the two representations. For example, the parser operates in the namespace where you "are", rather than the space that the expression will execute in. There are a number of situations where it would be unclear what precision a calculation is being done in.

There were strong arguments in favour of having different interpreters for DECF and DOUBLE, or at least a startup switch to select the representation for the session. In the end, "convenience" triumphed, to allows us to allow users to easily experiment with the effect of changing representations, and to help us more easily build and test the system - but we decided to limit it to session scope, in order to discourage people from getting into trouble by trying to write systems that switch between the representations "on the fly".
Erik.Friis
Posts: 66
Joined: Mon Apr 04, 2011 3:16 pm

Re: version 13 - []FR

Post by Erik.Friis »

When I mouse over the character in the APL char tape which is a quad overstruck with a colon I get "TRANSLATION ERROR" printed over and over again.
User avatar
AndyS|Dyalog
Posts: 263
Joined: Tue May 12, 2009 6:06 pm

Re: version 13 - []FR : problems with Variant

Post by AndyS|Dyalog »

Hi Erik

I suspect that you're running a Classic beta-test version of V13.0.

Variant (⍠) is not supported in the Classic version - for the simple reason that we've run out of free locations in ⎕AV and various fonts.

With the Classic version you should use ⎕OPT instead ..

With the full release of Dyalog APL V13.0 the Variant symbol no longer appears in the Language Bar ..
Post Reply