Factor out `InstallableStorePath` to its own file, dedup

`nix app` had something called `InstallableDerivedPath` which is
actually the same thing. We go with the later's name because it has
become more correct.

I originally did this change (more hurriedly) as part of #6225 --- a
mini store-only Nix and a full Nix need to share this code. In the first
RFC meeting for https://github.com/NixOS/rfcs/pull/134 we discussed how
some splitting of the massive `installables.cc` could begin prior, as
that is a good thing anyways. (@edolstra's words, not mine!) This would
be one such PR.

1 files changed, 2 insertions, 25 deletions

diff --git a/src/nix/app.cc b/src/nix/app.cc
index 08cd0ccd4..5cd65136f 100644
--- a/src/nix/app.cc
+++ b/src/nix/app.cc
@@ -1,4 +1,5 @@
 #include "installables.hh"
+#include "installable-derived-path.hh"
 #include "store-api.hh"
 #include "eval-inline.hh"
 #include "eval-cache.hh"
@@ -8,30 +9,6 @@
 
 namespace nix {
 
-struct InstallableDerivedPath : Installable
-{
-    ref<Store> store;
-    const DerivedPath derivedPath;
-
-    InstallableDerivedPath(ref<Store> store, const DerivedPath & derivedPath)
-        : store(store)
-        , derivedPath(derivedPath)
-    {
-    }
-
-    std::string what() const override { return derivedPath.to_string(*store); }
-
-    DerivedPathsWithInfo toDerivedPaths() override
-    {
-        return {{derivedPath}};
-    }
-
-    std::optional<StorePath> getStorePath() override
-    {
-        return std::nullopt;
-    }
-};
-
 /**
  * Return the rewrites that are needed to resolve a string whose context is
  * included in `dependencies`.
@@ -146,7 +123,7 @@ App UnresolvedApp::resolve(ref<Store> evalStore, ref<Store> store)
 
     for (auto & ctxElt : unresolved.context)
         installableContext.push_back(
-            std::make_shared<InstallableDerivedPath>(store, ctxElt));
+            std::make_shared<InstallableDerivedPath>(store, DerivedPath { ctxElt }));
 
     auto builtContext = Installable::build(evalStore, store, Realise::Outputs, installableContext);
     res.program = resolveString(*store, unresolved.program, builtContext);