Move /src to /subprojects

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

src/libcmd/installable-value.hh

@@ -1,121 +0,0 @@
-#pragma once
-///@file
-
-#include "installables.hh"
-#include "flake/flake.hh"
-
-namespace nix {
-
-struct PackageInfo;
-struct SourceExprCommand;
-
-namespace eval_cache { class EvalCache; class AttrCursor; }
-
-struct App
-{
-    std::vector<DerivedPath> context;
-    Path program;
-    // FIXME: add args, sandbox settings, metadata, ...
-};
-
-struct UnresolvedApp
-{
-    App unresolved;
-    App resolve(ref<Store> evalStore, ref<Store> store);
-};
-
-/**
- * Extra info about a \ref DerivedPath "derived path" that ultimately
- * come from a Nix language value.
- *
- * Invariant: every ExtraPathInfo gotten from an InstallableValue should
- * be possible to downcast to an ExtraPathInfoValue.
- */
-struct ExtraPathInfoValue : ExtraPathInfo
-{
-    /**
-     * Extra struct to get around C++ designated initializer limitations
-     */
-    struct Value {
-        /**
-         * An optional priority for use with "build envs". See Package
-         */
-        std::optional<NixInt::Inner> priority;
-
-        /**
-         * The attribute path associated with this value. The idea is
-         * that an installable referring to a value typically refers to
-         * a larger value, from which we project a smaller value out
-         * with this.
-         */
-        std::string attrPath;
-
-        /**
-         * \todo merge with DerivedPath's 'outputs' field?
-         */
-        ExtendedOutputsSpec extendedOutputsSpec;
-    };
-
-    Value value;
-
-    ExtraPathInfoValue(Value && v)
-        : value(v)
-    { }
-
-    virtual ~ExtraPathInfoValue() = default;
-};
-
-/**
- * An Installable which corresponds a Nix language value, in addition to
- * a collection of \ref DerivedPath "derived paths".
- */
-struct InstallableValue : Installable
-{
-    ref<EvalState> state;
-
-    InstallableValue(ref<EvalState> state) : state(state) {}
-
-    virtual ~InstallableValue() { }
-
-    virtual std::pair<Value *, PosIdx> toValue(EvalState & state) = 0;
-
-    /**
-     * Get a cursor to each value this Installable could refer to.
-     * However if none exists, throw exception instead of returning
-     * empty vector.
-     */
-    virtual std::vector<ref<eval_cache::AttrCursor>>
-    getCursors(EvalState & state);
-
-    /**
-     * Get the first and most preferred cursor this Installable could
-     * refer to, or throw an exception if none exists.
-     */
-    virtual ref<eval_cache::AttrCursor>
-    getCursor(EvalState & state);
-
-    UnresolvedApp toApp(EvalState & state);
-
-    static InstallableValue & require(Installable & installable);
-    static ref<InstallableValue> require(ref<Installable> installable);
-
-protected:
-
-    /**
-     * Handles either a plain path, or a string with a single string
-     * context elem in the right format. The latter case is handled by
-     * `EvalState::coerceToDerivedPath()`; see it for details.
-     *
-     * @param v Value that is hopefully a string or path per the above.
-     *
-     * @param pos Position of value to aid with diagnostics.
-     *
-     * @param errorCtx Arbitrary message for use in potential error message when something is wrong with `v`.
-     *
-     * @result A derived path (with empty info, for now) if the value
-     * matched the above criteria.
-     */
-    std::optional<DerivedPathWithInfo> trySinglePathToDerivedPaths(Value & v, const PosIdx pos, std::string_view errorCtx);
-};
-
-}