lib: Make overrideScope' which takes arguments in the conventional order

The `overrideScope` bound by `makeScope` (via special `callPackage`)
took an override in the form `super: self { … }`. But this is
dangerously close to the `self: super { … }` form used by *everything*
else, even other definitions of `overrideScope`! Since that
implementation did not even share any code either until I changed it
recently in 3cf43547f4, this inconsistency
is almost certainly an oversight and not intentional.

Unfortunately, just as the inconstency is hard to debug if one just
assumes the conventional order, any sudden fix would break existing
overrides in the same hard-to-debug way. So instead of changing the
definition a new `overrideScope'` with the conventional order is added,
and old `overrideScope` deprecated with a warning saying to use
`overrideScope'` instead. That will hopefully get people to stop using
`overrideScope`, freeing our hand to change or remove it in the future.
This commit is contained in:
John Ericson 2018-09-23 11:07:35 -04:00
parent 84c8e397d2
commit b9dce11712
3 changed files with 9 additions and 9 deletions

View file

@ -643,15 +643,15 @@ cp ${myEmacsConfig} $out/share/emacs/site-lisp/default.el
required dependencies manually - but it's tedious and there is always a
possibility that an unwanted dependency will sneak in through some other
package. To completely override such a package you can use
<varname>overrideScope</varname>.
<varname>overrideScope'</varname>.
</para>
<screen>
overrides = super: self: rec {
overrides = self: super: rec {
haskell-mode = self.melpaPackages.haskell-mode;
...
};
((emacsPackagesNgGen emacs).overrideScope overrides).emacsWithPackages (p: with p; [
((emacsPackagesNgGen emacs).overrideScope' overrides).emacsWithPackages (p: with p; [
# here both these package will use haskell-mode of our own choice
ghc-mod
dante

View file

@ -185,7 +185,7 @@ rec {
/* Make a set of packages with a common scope. All packages called
with the provided `callPackage' will be evaluated with the same
arguments. Any package in the set may depend on any other. The
`overrideScope' function allows subsequent modification of the package
`overrideScope'` function allows subsequent modification of the package
set in a consistent way, i.e. all packages in the set will be
called with the overridden packages. The package sets may be
hierarchical: the packages in the set are called with the scope
@ -195,10 +195,10 @@ rec {
let self = f self // {
newScope = scope: newScope (self // scope);
callPackage = self.newScope {};
# TODO(@Ericson2314): Haromonize argument order of `g` with everything else
overrideScope = g:
makeScope newScope
(lib.fixedPoints.extends (lib.flip g) f);
overrideScope = g: lib.warn
"`overrideScope` (from `lib.makeScope`) is deprecated. Do `overrideScope' (self: self: { })` instead of `overrideScope (super: self: { })`. All other overrides have the parameters in that order, including other definitions of `overrideScope`. This was the only definition violating the pattern."
(makeScope newScope (lib.fixedPoints.extends (lib.flip g) f));
overrideScope' = g: makeScope newScope (lib.fixedPoints.extends g f);
packages = f;
};
in self;

View file

@ -21,7 +21,7 @@ set which contains `emacsWithPackages`. For example, to override
`emacsPackagesNg.emacsWithPackages`,
```
let customEmacsPackages =
emacsPackagesNg.overrideScope (super: self: {
emacsPackagesNg.overrideScope' (self: super: {
# use a custom version of emacs
emacs = ...;
# use the unstable MELPA version of magit