Move /src to /subprojects

This will facilitate breaking up Nix into multiple packages for each
component with Meson.

src/libexpr/json-to-value.cc

@@ -1,180 +0,0 @@
-#include "json-to-value.hh"
-#include "value.hh"
-#include "eval.hh"
-
-#include <limits>
-#include <variant>
-#include <nlohmann/json.hpp>
-
-using json = nlohmann::json;
-
-namespace nix {
-
-// for more information, refer to
-// https://github.com/nlohmann/json/blob/master/include/nlohmann/detail/input/json_sax.hpp
-class JSONSax : nlohmann::json_sax<json> {
-    class JSONState {
-    protected:
-        std::unique_ptr<JSONState> parent;
-        RootValue v;
-    public:
-        virtual std::unique_ptr<JSONState> resolve(EvalState &)
-        {
-            throw std::logic_error("tried to close toplevel json parser state");
-        }
-        explicit JSONState(std::unique_ptr<JSONState> && p) : parent(std::move(p)) {}
-        explicit JSONState(Value * v) : v(allocRootValue(v)) {}
-        JSONState(JSONState & p) = delete;
-        Value & value(EvalState & state)
-        {
-            if (!v)
-                v = allocRootValue(state.allocValue());
-            return **v;
-        }
-        virtual ~JSONState() {}
-        virtual void add() {}
-    };
-
-    class JSONObjectState : public JSONState {
-        using JSONState::JSONState;
-        ValueMap attrs;
-        std::unique_ptr<JSONState> resolve(EvalState & state) override
-        {
-            auto attrs2 = state.buildBindings(attrs.size());
-            for (auto & i : attrs)
-                attrs2.insert(i.first, i.second);
-            parent->value(state).mkAttrs(attrs2);
-            return std::move(parent);
-        }
-        void add() override { v = nullptr; }
-    public:
-        void key(string_t & name, EvalState & state)
-        {
-            attrs.insert_or_assign(state.symbols.create(name), &value(state));
-        }
-    };
-
-    class JSONListState : public JSONState {
-        ValueVector values;
-        std::unique_ptr<JSONState> resolve(EvalState & state) override
-        {
-            auto list = state.buildList(values.size());
-            for (const auto & [n, v2] : enumerate(list))
-                v2 = values[n];
-            parent->value(state).mkList(list);
-            return std::move(parent);
-        }
-        void add() override {
-            values.push_back(*v);
-            v = nullptr;
-        }
-    public:
-        JSONListState(std::unique_ptr<JSONState> && p, std::size_t reserve) : JSONState(std::move(p))
-        {
-            values.reserve(reserve);
-        }
-    };
-
-    EvalState & state;
-    std::unique_ptr<JSONState> rs;
-
-public:
-    JSONSax(EvalState & state, Value & v) : state(state), rs(new JSONState(&v)) {};
-
-    bool null() override
-    {
-        rs->value(state).mkNull();
-        rs->add();
-        return true;
-    }
-
-    bool boolean(bool val) override
-    {
-        rs->value(state).mkBool(val);
-        rs->add();
-        return true;
-    }
-
-    bool number_integer(number_integer_t val) override
-    {
-        rs->value(state).mkInt(val);
-        rs->add();
-        return true;
-    }
-
-    bool number_unsigned(number_unsigned_t val_) override
-    {
-        if (val_ > std::numeric_limits<NixInt::Inner>::max()) {
-            throw Error("unsigned json number %1% outside of Nix integer range", val_);
-        }
-        NixInt::Inner val = val_;
-        rs->value(state).mkInt(val);
-        rs->add();
-        return true;
-    }
-
-    bool number_float(number_float_t val, const string_t & s) override
-    {
-        rs->value(state).mkFloat(val);
-        rs->add();
-        return true;
-    }
-
-    bool string(string_t & val) override
-    {
-        rs->value(state).mkString(val);
-        rs->add();
-        return true;
-    }
-
-#if NLOHMANN_JSON_VERSION_MAJOR >= 3 && NLOHMANN_JSON_VERSION_MINOR >= 8
-    bool binary(binary_t&) override
-    {
-        // This function ought to be unreachable
-        assert(false);
-        return true;
-    }
-#endif
-
-    bool start_object(std::size_t len) override
-    {
-        rs = std::make_unique<JSONObjectState>(std::move(rs));
-        return true;
-    }
-
-    bool key(string_t & name) override
-    {
-        dynamic_cast<JSONObjectState*>(rs.get())->key(name, state);
-        return true;
-    }
-
-    bool end_object() override {
-        rs = rs->resolve(state);
-        rs->add();
-        return true;
-    }
-
-    bool end_array() override {
-        return end_object();
-    }
-
-    bool start_array(size_t len) override {
-        rs = std::make_unique<JSONListState>(std::move(rs),
-            len != std::numeric_limits<size_t>::max() ? len : 128);
-        return true;
-    }
-
-    bool parse_error(std::size_t, const std::string&, const nlohmann::detail::exception& ex) override {
-        throw JSONParseError("%s", ex.what());
-    }
-};
-
-void parseJSON(EvalState & state, const std::string_view & s_, Value & v)
-{
-    JSONSax parser(state, v);
-    bool res = json::sax_parse(s_, &parser);
-    if (!res)
-        throw JSONParseError("Invalid JSON Value");
-}
-
-}