Initial flake support

2 files changed, 67 insertions, 37 deletions

diff --git a/src/nix/flake.cc b/src/nix/flake.cc
new file mode 100644
index 000000000..98cd90c64
--- /dev/null
+++ b/src/nix/flake.cc
@@ -0,0 +1,65 @@
+#include "command.hh"
+#include "common-args.hh"
+#include "shared.hh"
+#include "progress-bar.hh"
+#include "eval.hh"
+
+using namespace nix;
+
+struct CmdFlakeList : StoreCommand, MixEvalArgs
+{
+    std::string name() override
+    {
+        return "list";
+    }
+
+    std::string description() override
+    {
+        return "list available Nix flakes";
+    }
+
+    void run(nix::ref<nix::Store> store) override
+    {
+        auto evalState = std::make_shared<EvalState>(searchPath, store);
+
+        auto registry = evalState->getFlakeRegistry();
+
+        stopProgressBar();
+
+        for (auto & entry : registry.entries) {
+            std::cout << entry.first << " " << entry.second.uri << "\n";
+        }
+    }
+};
+
+struct CmdFlake : virtual MultiCommand, virtual Command
+{
+    CmdFlake()
+        : MultiCommand({make_ref<CmdFlakeList>()})
+    {
+    }
+
+    std::string name() override
+    {
+        return "flake";
+    }
+
+    std::string description() override
+    {
+        return "manage Nix flakes";
+    }
+
+    void run() override
+    {
+        if (!command)
+            throw UsageError("'nix flake' requires a sub-command.");
+        command->run();
+    }
+
+    void printHelp(const string & programName, std::ostream & out) override
+    {
+        MultiCommand::printHelp(programName, out);
+    }
+};
+
+static RegisterCommand r1(make_ref<CmdFlake>());
diff --git a/src/nix/installables.cc b/src/nix/installables.cc
index 0c1ad3ab3..9b7b96c25 100644
--- a/src/nix/installables.cc
+++ b/src/nix/installables.cc
@@ -26,47 +26,12 @@ Value * SourceExprCommand::getSourceExpr(EvalState & state)
 {
     if (vSourceExpr) return vSourceExpr;
 
-    auto sToplevel = state.symbols.create("_toplevel");
-
     vSourceExpr = state.allocValue();
 
     if (file != "")
         state.evalFile(lookupFileArg(state, file), *vSourceExpr);
-
-    else {
-
-        /* Construct the installation source from $NIX_PATH. */
-
-        auto searchPath = state.getSearchPath();
-
-        state.mkAttrs(*vSourceExpr, searchPath.size() + 1);
-
-        mkBool(*state.allocAttr(*vSourceExpr, sToplevel), true);
-
-        std::unordered_set<std::string> seen;
-
-        for (auto & i : searchPath) {
-            if (i.first == "") continue;
-            if (seen.count(i.first)) continue;
-            seen.insert(i.first);
-#if 0
-            auto res = state.resolveSearchPathElem(i);
-            if (!res.first) continue;
-            if (!pathExists(res.second)) continue;
-            mkApp(*state.allocAttr(*vSourceExpr, state.symbols.create(i.first)),
-                state.getBuiltin("import"),
-                mkString(*state.allocValue(), res.second));
-#endif
-            Value * v1 = state.allocValue();
-            mkPrimOpApp(*v1, state.getBuiltin("findFile"), state.getBuiltin("nixPath"));
-            Value * v2 = state.allocValue();
-            mkApp(*v2, *v1, mkString(*state.allocValue(), i.first));
-            mkApp(*state.allocAttr(*vSourceExpr, state.symbols.create(i.first)),
-                state.getBuiltin("import"), *v2);
-        }
-
-        vSourceExpr->attrs->sort();
-    }
+    else
+        state.evalFile(lookupFileArg(state, "<nix/default-installation-source.nix>"), *vSourceExpr);
 
     return vSourceExpr;
 }