Implemented "nix flake info"

src/libexpr/primops/flake.cc

@@ -141,19 +141,6 @@ static FlakeSourceInfo fetchFlake(EvalState & state, const FlakeRef & flakeRef)
     else abort();
 }
 
-struct Flake
-{
-    FlakeId id;
-    std::string description;
-    Path path;
-    std::vector<FlakeRef> requires;
-    std::unique_ptr<FlakeRegistry> lockFile;
-    Value * vProvides; // FIXME: gc
-    // commit hash
-    // date
-    // content hash
-};
-
 static Flake getFlake(EvalState & state, const FlakeRef & flakeRef)
 {
     auto sourceInfo = fetchFlake(state, flakeRef);

src/libexpr/primops/flake.hh

@@ -21,4 +21,18 @@ Value * makeFlakeRegistryValue(EvalState & state);
 
 Value * makeFlakeValue(EvalState & state, std::string flakeUri, Value & v);
 
+struct Flake
+{
+    FlakeId id;
+    std::string description;
+    Path path;
+    std::vector<FlakeRef> requires;
+    std::unique_ptr<FlakeRegistry> lockFile;
+    Value * vProvides; // FIXME: gc
+    // commit hash
+    // date
+    // content hash
+};
+
+static Flake getFlake(EvalState & state, const FlakeRef & flakeRef);
 }

src/nix/command.hh

@@ -34,6 +34,17 @@ struct Buildable
 
 typedef std::vector<Buildable> Buildables;
 
+struct FlakeCommand : virtual Args, StoreCommand, MixEvalArgs
+{
+  std::string flakeUri;
+
+public:
+  FlakeCommand()
+  {
+    expectArg("flake-uri", &flakeUri);
+  }
+};
+
 struct Installable
 {
     virtual std::string what() = 0;

src/nix/flake.cc

@@ -33,10 +33,31 @@ struct CmdFlakeList : StoreCommand, MixEvalArgs
     }
 };
 
+struct CmdFlakeInfo : FlakeCommand
+{
+    std::string name() override
+    {
+        return "info";
+    }
+
+    std::string description() override
+    {
+        return "list info about a given flake";
+    }
+
+    void run(nix::ref<nix::Store> store) override
+    {
+        auto evalState = std::make_shared<EvalState>(searchPath, store);
+        nix::Flake flake = nix::getFlake(*evalState, FlakeRef(flakeUri));
+        std::cout << "Location:    " << flake.path << "\n";
+        std::cout << "Description: " << flake.description << "\n";
+    }
+};
+
 struct CmdFlake : virtual MultiCommand, virtual Command
 {
     CmdFlake()
-        : MultiCommand({make_ref<CmdFlakeList>()})
+        : MultiCommand({make_ref<CmdFlakeList>(), make_ref<CmdFlakeInfo>()})
     {
     }