1 files changed, 32 insertions, 30 deletions

diff --git a/src/libexpr/value-to-json.cc b/src/libexpr/value-to-json.cc
index 7b35abca2..5dc453b2e 100644
--- a/src/libexpr/value-to-json.cc
+++ b/src/libexpr/value-to-json.cc
@@ -1,105 +1,107 @@
 #include "value-to-json.hh"
-#include "json.hh"
 #include "eval-inline.hh"
 #include "util.hh"
 
 #include <cstdlib>
 #include <iomanip>
+#include <nlohmann/json.hpp>
 
 
 namespace nix {
-
-void printValueAsJSON(EvalState & state, bool strict,
-    Value & v, const Pos & pos, JSONPlaceholder & out, PathSet & context)
+using json = nlohmann::json;
+json printValueAsJSON(EvalState & state, bool strict,
+    Value & v, const PosIdx pos, PathSet & context, bool copyToStore)
 {
     checkInterrupt();
 
     if (strict) state.forceValue(v, pos);
 
+    json out;
+
     switch (v.type()) {
 
         case nInt:
-            out.write(v.integer);
+            out = v.integer;
             break;
 
         case nBool:
-            out.write(v.boolean);
+            out = v.boolean;
             break;
 
         case nString:
             copyContext(v, context);
-            out.write(v.string.s);
+            out = v.string.s;
             break;
 
         case nPath:
-            out.write(state.copyPathToStore(context, v.path));
+            if (copyToStore)
+                out = state.copyPathToStore(context, v.path);
+            else
+                out = v.path;
             break;
 
         case nNull:
-            out.write(nullptr);
             break;
 
         case nAttrs: {
             auto maybeString = state.tryAttrsToString(pos, v, context, false, false);
             if (maybeString) {
-                out.write(*maybeString);
+                out = *maybeString;
                 break;
             }
             auto i = v.attrs->find(state.sOutPath);
             if (i == v.attrs->end()) {
-                auto obj(out.object());
+                out = json::object();
                 StringSet names;
                 for (auto & j : *v.attrs)
-                    names.insert(j.name);
+                    names.emplace(state.symbols[j.name]);
                 for (auto & j : names) {
                     Attr & a(*v.attrs->find(state.symbols.create(j)));
-                    auto placeholder(obj.placeholder(j));
-                    printValueAsJSON(state, strict, *a.value, *a.pos, placeholder, context);
+                    out[j] = printValueAsJSON(state, strict, *a.value, a.pos, context, copyToStore);
                 }
             } else
-                printValueAsJSON(state, strict, *i->value, *i->pos, out, context);
+                return printValueAsJSON(state, strict, *i->value, i->pos, context, copyToStore);
             break;
         }
 
         case nList: {
-            auto list(out.list());
-            for (auto elem : v.listItems()) {
-                auto placeholder(list.placeholder());
-                printValueAsJSON(state, strict, *elem, pos, placeholder, context);
-            }
+            out = json::array();
+            for (auto elem : v.listItems())
+                out.push_back(printValueAsJSON(state, strict, *elem, pos, context, copyToStore));
             break;
         }
 
         case nExternal:
-            v.external->printValueAsJSON(state, strict, out, context);
+            return v.external->printValueAsJSON(state, strict, context, copyToStore);
             break;
 
         case nFloat:
-            out.write(v.fpoint);
+            out = v.fpoint;
             break;
 
         case nThunk:
         case nFunction:
             auto e = TypeError({
                 .msg = hintfmt("cannot convert %1% to JSON", showType(v)),
-                .errPos = v.determinePos(pos)
+                .errPos = state.positions[v.determinePos(pos)]
             });
-            e.addTrace(pos, hintfmt("message for the trace"));
+            e.addTrace(state.positions[pos], hintfmt("message for the trace"));
+            state.debugThrowLastTrace(e);
             throw e;
     }
+    return out;
 }
 
 void printValueAsJSON(EvalState & state, bool strict,
-    Value & v, const Pos & pos, std::ostream & str, PathSet & context)
+    Value & v, const PosIdx pos, std::ostream & str, PathSet & context, bool copyToStore)
 {
-    JSONPlaceholder out(str);
-    printValueAsJSON(state, strict, v, pos, out, context);
+    str << printValueAsJSON(state, strict, v, pos, context, copyToStore);
 }
 
-void ExternalValueBase::printValueAsJSON(EvalState & state, bool strict,
-    JSONPlaceholder & out, PathSet & context) const
+json ExternalValueBase::printValueAsJSON(EvalState & state, bool strict,
+    PathSet & context, bool copyToStore) const
 {
-    throw TypeError("cannot convert %1% to JSON", showType());
+    state.debugThrowLastTrace(TypeError("cannot convert %1% to JSON", showType()));
 }