Feature #1174
package of a function --> of an identifier!
Description
How to have a function that says in which package is in the input?
Why does not describe have this feature?!
2021-01 PackageOf("<name>");
describe cannot know the package, because it receives the evaluated object, and not its name/identifier.
Related issues
History
#1
Updated by John Abbott about 6 years ago
Updated by - Related to Feature #346: Describe should indicate package name added
#2
Updated by Anna Maria Bigatti over 5 years ago
Updated by - Category set to CoCoA-5 function: new
- Assignee set to Anna Maria Bigatti
- Target version set to CoCoA-5.2.4
Waiting for a proper implementation in C++, we can do something like starting.
#3
Updated by Anna Maria Bigatti over 5 years ago
- Related to Bug #1200: Package exported function: wrong package name added
#4
Updated by Anna Maria Bigatti over 5 years ago
- Target version changed from CoCoA-5.2.4 to CoCoA-5.3.0
#5
Updated by John Abbott over 4 years ago
- Priority changed from Normal to High
- Target version changed from CoCoA-5.3.0 to CoCoA-5.4.0
#6
Updated by John Abbott about 4 years ago
As Anna said in comment 2: the function starting is able to get the information. So we should look there to see how to do it.
#7
Updated by John Abbott over 3 years ago
Anna has a prototype in coclib.cpkg5. Currently commented out -- how long has it been there??
If it were built-in then it could be used by describe.
#8
Updated by Anna Maria Bigatti over 3 years ago
- Status changed from New to In Progress
- % Done changed from 0 to 50
#9
Updated by Anna Maria Bigatti over 3 years ago
- % Done changed from 50 to 60
should the name be PackageOf?
I have investigated: belonging to a package (variable) is a property of the variable (VariableSlot), not of the value of the variable.
Now I have written a function in Interpreter.C taking a string (the variable name).
There was a function called findOwner (now FindOwnerPkg) in Interpreter.C in anonymous name space. I used it.
Can I make PackageOf take a variable? will see
#10
Updated by Anna Maria Bigatti over 3 years ago
- Related to Feature #531: Package protected variables should know which package protected them added
#11
Updated by Anna Maria Bigatti over 3 years ago
Example:
/**/ anna := starting;
/**/ PackageOf("starting");
$coclib
/**/ PackageOf("anna");
<not in a package>
So, to have it working with the variable, not the string with the variable name, the argument should not be evaluated, as it happens for IsDefined (only case like that)
#12
Updated by John Abbott over 3 years ago
Well done! I suggest we accept the version taking a string for the time being (unless you can easily make a fn like IsDefined).
When exactly is it useful to find the package? I think I use it only when debugging (or perhaps if the documentation seems unclear, and I want to see what the code actually does).
Other things which do not evaluate a variable are: describe, (un)protect.
#13
Updated by Anna Maria Bigatti over 3 years ago
- Subject changed from package of a function to package of a function --> of an identifier!
#14
Updated by Anna Maria Bigatti about 3 years ago
- Description updated (diff)
- Status changed from In Progress to Feedback
- % Done changed from 60 to 90
I'm now convinced that the only exception to the evaluation of the argument of a function should be IsDefined. There is no point in making an exception for such a small function as PackageOf.
So, in conclusion, the only great advantage of PackageOf vs starting is the good name ;-)
It is also faster, but it's pretty irrelevant for its tipical use (i.e. not within loops).
#15
Updated by Anna Maria Bigatti about 3 years ago
- Status changed from Feedback to Closed
- % Done changed from 90 to 100