Opened 10 years ago
Closed 10 years ago
#13586 closed defect (fixed)
BuiltinFunction expects to be instantiated only once
Reported by: | burcin | Owned by: | burcin |
---|---|---|---|
Priority: | major | Milestone: | sage-5.5 |
Component: | symbolics | Keywords: | symbolic function |
Cc: | Merged in: | sage-5.5.beta0 | |
Authors: | Burcin Erocal | Reviewers: | Karl-Dieter Crisman |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
From this ask.sagemath.org question:
sage: from sage.symbolic.function import BuiltinFunction sage: class AFunction(BuiltinFunction): ....: def __init__(self, name, exp=1): ....: self.exponent=exp ....: BuiltinFunction.__init__(self, name, nargs=1) ....: def _eval_(self, arg): ....: return arg**self.exponent ....: sage: p2 = AFunction('p2', 2) sage: p2(x) x^2 sage: p3 = AFunction('p3', 3) sage: p3(x) x^2
ATM, we only allow a BuiltinFunction
to be instantiated once.
Attachments (1)
Change History (6)
Changed 10 years ago by
comment:1 Changed 10 years ago by
- Status changed from new to needs_review
comment:2 follow-up: ↓ 3 Changed 10 years ago by
- Description modified (diff)
- Reviewers set to Karl-Dieter Crisman
- Status changed from needs_review to positive_review
comment:3 in reply to: ↑ 2 Changed 10 years ago by
Thanks for the quick review.
Replying to kcrisman:
Similarly, is this (new behavior, I think) ok? I think so, but just want to make sure.
sage: class MyFunction(BuiltinFunction): ....: def __init__(self,name): ....: self.exponent=1 ....: BuiltinFunction.__init__(self,name,nargs=1) ....: def _eval_(self,arg): ....: return arg**self.exponent ....: sage: MyFunction('p') p sage: p = MyFunction('p') sage: p p sage: p(2) 2 sage: p(3) 3 sage: q = MyFunction('q') sage: q(3) 3 sage: p p sage: q q
I think this is how it used to work without the patch as well. But I admit that I don't understand your question. Are you surprised that q
prints as q
not p
? We always use the user supplied name when printing the instance object. It's a different matter for the self
argument you have inside the _eval_()
function.
comment:4 Changed 10 years ago by
No, it's just that you said "ATM, we only allow a BuiltinFunction? to be instantiated once." Whereas now it can be instantiated more than once with or without different arguments etc. Probably this is ok, I just wanted to be sure. No problem.
comment:5 Changed 10 years ago by
- Merged in set to sage-5.5.beta0
- Resolution set to fixed
- Status changed from positive_review to closed
Nice work, Burcin. I guess this doesn't stop someone from doing
but I suppose that is the user's problem, since they are redefining the name
p2
. Similarly, is this (new behavior, I think) ok? I think so, but just want to make sure.Patchbot: Apply trac_13586-builtin_function.patch