Unverified Commit 7eddbf56 authored by Silvan Mosberger's avatar Silvan Mosberger Committed by GitHub
Browse files

Merge pull request #265710 from ShamrockLee/lib-copy-function-args 

lib.mirrorFunctionArgs: init
parents 5d6c7322 b3e2c150

lib/customisation.nix

+10 −8
Original line number Diff line number Diff line
@@ -76,19 +76,22 @@ rec { 
     Type:

       makeOverridable :: (AttrSet -> a) -> AttrSet -> a

  */

  makeOverridable = f: lib.setFunctionArgs

    (origArgs: let

  makeOverridable = f:

    let

      # Creates a functor with the same arguments as f

      mirrorArgs = lib.mirrorFunctionArgs f;

    in

    mirrorArgs (origArgs:

    let

      result = f origArgs;



      # Creates a functor with the same arguments as f

      copyArgs = g: lib.setFunctionArgs g (lib.functionArgs f);

      # Changes the original arguments with (potentially a function that returns) a set of new attributes

      overrideWith = newArgs: origArgs // (if lib.isFunction newArgs then newArgs origArgs else newArgs);



      # Re-call the function but with different arguments

      overrideArgs = copyArgs (newArgs: makeOverridable f (overrideWith newArgs));

      overrideArgs = mirrorArgs (newArgs: makeOverridable f (overrideWith newArgs));

      # Change the result of the function call by applying g to it

      overrideResult = g: makeOverridable (copyArgs (args: g (f args))) origArgs;

      overrideResult = g: makeOverridable (mirrorArgs (args: g (f args))) origArgs;

    in

      if builtins.isAttrs result then

        result // {
@@ -102,8 +105,7 @@ rec { 
        lib.setFunctionArgs result (lib.functionArgs result) // {

          override = overrideArgs;

        }

      else result)

    (lib.functionArgs f);

      else result);





  /* Call the package function in the file `fn` with the required

lib/default.nix

+1 −1
Original line number Diff line number Diff line
@@ -74,7 +74,7 @@ let 
      importJSON importTOML warn warnIf warnIfNot throwIf throwIfNot checkListOfEnum

      info showWarnings nixpkgsVersion version isInOldestRelease

      mod compare splitByAndCompare

      functionArgs setFunctionArgs isFunction toFunction

      functionArgs setFunctionArgs isFunction toFunction mirrorFunctionArgs

      toHexString toBaseDigits inPureEvalMode;

    inherit (self.fixedPoints) fix fix' converge extends composeExtensions

      composeManyExtensions makeExtensible makeExtensibleWithCustomName;

lib/trivial.nix

+34 −0
Original line number Diff line number Diff line
@@ -448,6 +448,40 @@ rec { 
  isFunction = f: builtins.isFunction f ||

    (f ? __functor && isFunction (f.__functor f));



  /*

    `mirrorFunctionArgs f g` creates a new function `g'` with the same behavior as `g` (`g' x == g x`)

    but its function arguments mirroring `f` (`lib.functionArgs g' == lib.functionArgs f`).



    Type:

      mirrorFunctionArgs :: (a -> b) -> (a -> c) -> (a -> c)



    Example:

      addab = {a, b}: a + b

      addab { a = 2; b = 4; }

      => 6

      lib.functionArgs addab

      => { a = false; b = false; }

      addab1 = attrs: addab attrs + 1

      addab1 { a = 2; b = 4; }

      => 7

      lib.functionArgs addab1

      => { }

      addab1' = lib.mirrorFunctionArgs addab addab1

      addab1' { a = 2; b = 4; }

      => 7

      lib.functionArgs addab1'

      => { a = false; b = false; }

  */

  mirrorFunctionArgs =

    # Function to provide the argument metadata

    f:

    let

      fArgs = functionArgs f;

    in

    # Function to set the argument metadata to

    g:

    setFunctionArgs g fArgs;



  /*

    Turns any non-callable values into constant functions.

    Returns callable values as is.

pkgs/development/interpreters/python/python-packages-base.nix

+2 −2
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ let 


  # Derivations built with `buildPythonPackage` can already be overridden with `override`, `overrideAttrs`, and `overrideDerivation`.

  # This function introduces `overridePythonAttrs` and it overrides the call to `buildPythonPackage`.

  makeOverridablePythonPackage = f: origArgs:

  makeOverridablePythonPackage = f: lib.mirrorFunctionArgs f (origArgs:

    let

      args = lib.fix (lib.extends

        (_: previousAttrs: {
@@ -30,7 +30,7 @@ let 
        overridePythonAttrs = newArgs: makeOverridablePythonPackage f (overrideWith newArgs);

        __functor = self: result;

      }

      else result;

      else result);



  mkPythonDerivation = if python.isPy3k then

    ./mk-python-derivation.nix