Move `PodIdx` to `pos-idx.hh` and `PosTable` to `pos-table.hh`

(cherry picked from commit c62c21e29af20f1c14a59ab37d7a25dd0b70f69e)
Change-Id: Id4ea2fc33b0874b2f1f2a32cabcbeb0afa26808f

1 files changed, 2 insertions, 84 deletions

diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh
index 4b41fe1fc..84f66ba4c 100644
--- a/src/libexpr/nixexpr.hh
+++ b/src/libexpr/nixexpr.hh
@@ -9,6 +9,8 @@
 #include "error.hh"
 #include "chunked-vector.hh"
 #include "position.hh"
+#include "pos-idx.hh"
+#include "pos-table.hh"
 
 namespace nix {
 
@@ -30,90 +32,6 @@ public:
     using EvalError::EvalError;
 };
 
-class PosIdx {
-    friend class PosTable;
-
-private:
-    uint32_t id;
-
-    explicit PosIdx(uint32_t id): id(id) {}
-
-public:
-    PosIdx() : id(0) {}
-
-    explicit operator bool() const { return id > 0; }
-
-    bool operator <(const PosIdx other) const { return id < other.id; }
-
-    bool operator ==(const PosIdx other) const { return id == other.id; }
-
-    bool operator !=(const PosIdx other) const { return id != other.id; }
-};
-
-class PosTable
-{
-public:
-    class Origin {
-        friend PosTable;
-    private:
-        // must always be invalid by default, add() replaces this with the actual value.
-        // subsequent add() calls use this index as a token to quickly check whether the
-        // current origins.back() can be reused or not.
-        mutable uint32_t idx = std::numeric_limits<uint32_t>::max();
-
-        // Used for searching in PosTable::[].
-        explicit Origin(uint32_t idx): idx(idx), origin{std::monostate()} {}
-
-    public:
-        const Pos::Origin origin;
-
-        Origin(Pos::Origin origin): origin(origin) {}
-    };
-
-    struct Offset {
-        uint32_t line, column;
-    };
-
-private:
-    std::vector<Origin> origins;
-    ChunkedVector<Offset, 8192> offsets;
-
-public:
-    PosTable(): offsets(1024)
-    {
-        origins.reserve(1024);
-    }
-
-    PosIdx add(const Origin & origin, uint32_t line, uint32_t column)
-    {
-        const auto idx = offsets.add({line, column}).second;
-        if (origins.empty() || origins.back().idx != origin.idx) {
-            origin.idx = idx;
-            origins.push_back(origin);
-        }
-        return PosIdx(idx + 1);
-    }
-
-    Pos operator[](PosIdx p) const
-    {
-        if (p.id == 0 || p.id > offsets.size())
-            return {};
-        const auto idx = p.id - 1;
-        /* we want the last key <= idx, so we'll take prev(first key > idx).
-           this is guaranteed to never rewind origin.begin because the first
-           key is always 0. */
-        const auto pastOrigin = std::upper_bound(
-            origins.begin(), origins.end(), Origin(idx),
-            [] (const auto & a, const auto & b) { return a.idx < b.idx; });
-        const auto origin = *std::prev(pastOrigin);
-        const auto offset = offsets[idx];
-        return {offset.line, offset.column, origin.origin};
-    }
-};
-
-inline PosIdx noPos = {};
-
-
 struct Env;
 struct Value;
 class EvalState;