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Re: A plan for parameterized packages
From: |
Ludovic Courtès |
Subject: |
Re: A plan for parameterized packages |
Date: |
Mon, 16 Nov 2020 12:54:22 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) |
Hi,
zimoun <zimon.toutoune@gmail.com> skribis:
>> To me the requirements for package parameters are:
>>
>> 1. it must be possible to discover them and choose them from the UI;
>>
>> 2. they must contain on-line internationalized documentation such that
>> the UI can list a package’s parameters and their type;
>
> Except ’boolean’, which kind of type do you have in mind? Aside that
> you did not find examples of packages requiring parameters. ;-)
Another example would be enumerated types.
>> 3. the chosen parameters when installing a package in a profile must
>> be preserved;
>
> You mean track the parameters with ’properties’ in <profile>/manifest,
> right?
Yup!
>> 4. it must be possible to enumerate all the possible values of a
>> parameter, and thus to build the Cartesian product of all the
>> possible parameter combinations of a package (or of a package
>> graph!), so we can test those combinations as much as possible.
>
> The values of the option are therefore known at package time, right?
> However, this implies restricted possibility for the type, right?
The <package-parameter> record has to specify a type, and the type must
have a finite universe. So there cannot be an “integer” type, for
instance, but there can be “integer between 10 and 42”.
>> +(define (evaluate-parameter-specs specs proc)
>> + "Parse SPECS, a list of strings like \"bitlbee=purple=true\", and return a
>> +list of spec/procedure pairs, where (PROC PACKAGE PARAMETER VALUE) is called
>> +to return the replacement package. Raise an error if an element of SPECS
>> uses
>> +invalid syntax, or if a package it refers to could not be found."
>> + (map (lambda (spec)
>> + (match (string-tokenize spec %not-equal)
>> + ((spec name value)
>> + (define (replace old)
>> + (proc old name value))
>> +
>> + (cons spec replace))
>> + (_
>> + (raise
>> + (formatted-message
>> + (G_ "invalid package parameter specification: ~s")
>> + spec)))))
>> + specs))
>
> Here ’proc’ could be anything, right? But then…
>
>> +(define (transform-package-parameters replacement-specs)
>> + "Return a procedure that, when passed a package, replaces its direct
>> +dependencies according to REPLACEMENT-SPECS. REPLACEMENT-SPECS is a list of
>> +strings like \"guile-next=stable-3.0\" meaning that packages are built using
>> +'guile-next' from the latest commit on its 'stable-3.0' branch."
>> + (define (replace old name value)
>> + (set-package-parameter-value old name value))
>> +
>> + (let* ((replacements (evaluate-parameter-specs replacement-specs
>> + replace))
>> + (rewrite (package-input-rewriting/spec replacements)))
>> + (lambda (obj)
>> + (if (package? obj)
>> + (rewrite obj)
>> + obj))))
>
> … it is ’set-package-parameter-value’. It is not clear in my mind.
Yes I could have used ‘set-package-parameter-value’ directly instead of
adding this ‘proc’ parameter; it would have been more readable I guess!
Thanks,
Ludo’.
Re: A plan for parameterized packages, zimoun, 2020/11/15
- Re: A plan for parameterized packages,
Ludovic Courtès <=
Re: A plan for parameterized packages, Taylan Kammer, 2020/11/15
Re: A plan for parameterized packages, Danny Milosavljevic, 2020/11/15
Re: A plan for parameterized packages, raingloom, 2020/11/15
Re: A plan for parameterized packages, Denis 'GNUtoo' Carikli, 2020/11/19