version 13 - []FR

General APL language issues

version 13 - []FR

Postby giangiquario on Mon Mar 28, 2011 3:33 pm

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
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Re: version 13 - []FR

Postby Morten|Dyalog on Tue Mar 29, 2011 7:13 am

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".
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Re: version 13 - []FR

Postby Erik.Friis on Tue Apr 05, 2011 1:48 am

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

Postby AndyS|Dyalog on Tue Apr 05, 2011 8:24 am

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 ..
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