guix/corepkgs/derivation.nix

/* This is the implementation of the ‘derivation’ builtin function.
   It's actually a wrapper around the ‘derivationStrict’ primop. */

drvAttrs @ { outputs ? [ "out" ], ... }:

let

  strict = derivationStrict drvAttrs;

  commonAttrs = drvAttrs // (builtins.listToAttrs outputsList) //
    { all = map (x: x.value) outputsList;
      inherit drvAttrs;
    };

  outputToAttrListElement = outputName:
    { name = outputName;
      value = commonAttrs // {
        outPath = builtins.getAttr outputName strict;
        drvPath = strict.drvPath;
        type = "derivation";
        inherit outputName;
      };
    };

  outputsList = map outputToAttrListElement outputs;

in (builtins.head outputsList).value
-												* Simplify the implementation of "derivation" a bit: lift out the
  common attribution so that they're evaluated only once, etc.  Note
  that the default output is now the first element of the "outputs"
  attribute, rather than the first element of the sorted list of
  outputs.  This seems more user-friendly.


											
										
										
											2012-01-04 11:04:19 +00:00
+								/* This is the implementation of the ‘derivation’ builtin function.
 								   It's actually a wrapper around the ‘derivationStrict’ primop. */
 								drvAttrs @ { outputs ? [ "out" ], ... }:
-												* Move the implementation of the ‘derivation’ primop into a separate
  file.


											
										
										
											2012-01-03 14:01:47 +00:00
 								let
-												* Simplify the implementation of "derivation" a bit: lift out the
  common attribution so that they're evaluated only once, etc.  Note
  that the default output is now the first element of the "outputs"
  attribute, rather than the first element of the sorted list of
  outputs.  This seems more user-friendly.


											
										
										
											2012-01-04 11:04:19 +00:00
+								  strict = derivationStrict drvAttrs;
-												Make "nix-build -A <derivation>.<output>" do the right thing

For example, given a derivation with outputs "out", "man" and "bin":

  $ nix-build -A pkg

produces ./result pointing to the "out" output;

  $ nix-build -A pkg.man

produces ./result-man pointing to the "man" output;

  $ nix-build -A pkg.all

produces ./result, ./result-man and ./result-bin;

  $ nix-build -A pkg.all -A pkg2

produces ./result, ./result-man, ./result-bin and ./result-2.

											
										
										
											2012-11-26 14:39:10 +00:00
-												* Export the original input attributes of the derivation in
  ‘drvAttrs’.  This will simplify the implementation of functions such
  as ‘overrideDerivation’ in Nixpkgs, which need to filter out any
  added attributes such as outPath.


											
										
										
											2012-01-04 11:56:15 +00:00
+								  commonAttrs = drvAttrs // (builtins.listToAttrs outputsList) //
 								    { all = map (x: x.value) outputsList;
 								      inherit drvAttrs;
 								    };
-												* Simplify the implementation of "derivation" a bit: lift out the
  common attribution so that they're evaluated only once, etc.  Note
  that the default output is now the first element of the "outputs"
  attribute, rather than the first element of the sorted list of
  outputs.  This seems more user-friendly.


											
										
										
											2012-01-04 11:04:19 +00:00
-												* Drop the inefficient "Path" suffix in output attribute names.


											
										
										
											2012-01-03 15:27:18 +00:00
+								  outputToAttrListElement = outputName:
 								    { name = outputName;
-												* Simplify the implementation of "derivation" a bit: lift out the
  common attribution so that they're evaluated only once, etc.  Note
  that the default output is now the first element of the "outputs"
  attribute, rather than the first element of the sorted list of
  outputs.  This seems more user-friendly.


											
										
										
											2012-01-04 11:04:19 +00:00
+								      value = commonAttrs // {
-												* Drop the inefficient "Path" suffix in output attribute names.


											
										
										
											2012-01-03 15:27:18 +00:00
+								        outPath = builtins.getAttr outputName strict;
-												* Move the implementation of the ‘derivation’ primop into a separate
  file.


											
										
										
											2012-01-03 14:01:47 +00:00
+								        drvPath = strict.drvPath;
 								        type = "derivation";
-												* currentOutput -> outputName.  "current" implies some temporal
  aspect.


											
										
										
											2012-01-04 12:00:39 +00:00
+								        inherit outputName;
-												* Simplify the implementation of "derivation" a bit: lift out the
  common attribution so that they're evaluated only once, etc.  Note
  that the default output is now the first element of the "outputs"
  attribute, rather than the first element of the sorted list of
  outputs.  This seems more user-friendly.


											
										
										
											2012-01-04 11:04:19 +00:00
+								      };
-												* Move the implementation of the ‘derivation’ primop into a separate
  file.


											
										
										
											2012-01-03 14:01:47 +00:00
+								    };
-												Make "nix-build -A <derivation>.<output>" do the right thing

For example, given a derivation with outputs "out", "man" and "bin":

  $ nix-build -A pkg

produces ./result pointing to the "out" output;

  $ nix-build -A pkg.man

produces ./result-man pointing to the "man" output;

  $ nix-build -A pkg.all

produces ./result, ./result-man and ./result-bin;

  $ nix-build -A pkg.all -A pkg2

produces ./result, ./result-man, ./result-bin and ./result-2.

											
										
										
											2012-11-26 14:39:10 +00:00
-												* Simplify the implementation of "derivation" a bit: lift out the
  common attribution so that they're evaluated only once, etc.  Note
  that the default output is now the first element of the "outputs"
  attribute, rather than the first element of the sorted list of
  outputs.  This seems more user-friendly.


											
										
										
											2012-01-04 11:04:19 +00:00
+								  outputsList = map outputToAttrListElement outputs;
-												Make "nix-build -A <derivation>.<output>" do the right thing

For example, given a derivation with outputs "out", "man" and "bin":

  $ nix-build -A pkg

produces ./result pointing to the "out" output;

  $ nix-build -A pkg.man

produces ./result-man pointing to the "man" output;

  $ nix-build -A pkg.all

produces ./result, ./result-man and ./result-bin;

  $ nix-build -A pkg.all -A pkg2

produces ./result, ./result-man, ./result-bin and ./result-2.

											
										
										
											2012-11-26 14:39:10 +00:00
-												* Simplify the implementation of "derivation" a bit: lift out the
  common attribution so that they're evaluated only once, etc.  Note
  that the default output is now the first element of the "outputs"
  attribute, rather than the first element of the sorted list of
  outputs.  This seems more user-friendly.


											
										
										
											2012-01-04 11:04:19 +00:00
+								in (builtins.head outputsList).value