Opened 12 years ago

Last modified 12 years ago

#8317 new enhancement

Prevent assignments to special names

Reported by: olazo Owned by: olazo
Priority: major Milestone: sage-wishlist
Component: misc Keywords: assignation, names
Cc: Merged in:
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Description (last modified by olazo)

I'd like to propose that certain special names should be protected so that they could not become variable names (for example pi, e, and i)

if by accident you assign them like:

sage: e=factorial(10)

and then you need to need to use e with it's standard meaning, like

sage: e^100

you will have a very hard time finding the error ( factorial(10)^100 ).

this has been discussed in: http://groups.google.com/group/sage-support/browse_thread/thread/b391ed6bd14cdfd0

and

http://groups.google.com/group/sage-devel/browse_thread/thread/a8e1e4ffe24840dc

Change History (4)

comment:1 Changed 12 years ago by olazo

  • Component changed from misc to symbolics
  • Description modified (diff)

comment:2 Changed 12 years ago by was

his is something that can (and will) be made an optional mode. We'll have several -- implicit multiplication, automatic variable name creation, and protected names. Having them all on could be useful for people teaching, e.g., calculus labs. This protected mode, by the way, will in the long run use the same technique as automatic variable name creation: replacing the globals() dictionary by a customized wrapper. This has a slight performance penalty, so definitely can't be the default. But it is a fine idea for an optional mode.

comment:3 Changed 12 years ago by burcin

  • Component changed from symbolics to misc
  • Milestone set to sage-wishlist
  • Summary changed from Protecting special names against assignation to Prevent assignments to special names
  • Type changed from defect to enhancement

I see that this would be a desirable feature for users of symbolics. I don't think the implementation is related to the symbolics subsystem however. I'm assigning this back to the misc component.

comment:4 Changed 12 years ago by olazo

  • Description modified (diff)
  • Priority changed from minor to major
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