Opened 9 years ago
Closed 7 years ago
#9662 closed defect (invalid)
gp(string) always returns a value, even when it should not
Reported by: | jdemeyer | Owned by: | was |
---|---|---|---|
Priority: | major | Milestone: | sage-duplicate/invalid/wontfix |
Component: | interfaces | Keywords: | pari |
Cc: | Merged in: | ||
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
When executing a GP command using the Sage interface, a value of 0 is returned when None would be expected. For example, in a gp shell (started with sage -gp for example):
gp> kill(x) /* No output */
But in Sage:
sage: gp('kill(x)') 0
Change History (3)
comment:1 Changed 9 years ago by
comment:2 Changed 9 years ago by
- Keywords pari added
comment:3 Changed 7 years ago by
- Milestone changed from sage-5.11 to sage-duplicate/invalid/wontfix
- Resolution set to invalid
- Status changed from new to closed
I agree that this is invalid. Doing gp('kill(x)')
means to create an object "kill(x)" in gp, assign it to a variable, and return a object pointing to that variable.
sage: type(gp('kill(x)')) <class 'sage.interfaces.gp.GpElement'>
This is how it works for all the interfaces. If you just want to evaluate a command, then you can do
sage: gp.eval('kill(x)') ''
which appropriately returns an empty string.
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This is not easily fixed, it is due to the way how Expect assigns variables. In fact, one could argue that the observed behaviour is as expected, because in gp, we get
So, assigning a nil value makes it into a zero.