refactored SearchExpression

2026-09-15 13:18:09 +02:00
parent 1d53f6930a
commit 5b1b8f4ce5
21 changed files with 509 additions and 216 deletions
@@ -0,0 +1,50 @@
+namespace ParadoxSaveParser.Lib;
+
+/// <summary>
+///     One step of a compiled query. Each step points at the step its matched nodes
+///     are searched with, so the query runs in a single pass down the tree.
+/// </summary>
+public interface ISearchExpression
+{
+    /// <summary>Tests one node against this step of the query.</summary>
+    /// <param name="candidate">The node being tested, identified by its key or its position.</param>
+    /// <param name="nextSearchExpression">
+    ///     On a match, the step for the node's children, or <c>null</c> if the node is kept whole.
+    ///     Undefined when the method returns <c>false</c>.
+    /// </param>
+    /// <returns>true if the node is selected by this step</returns>
+    bool DoesMatch(MatchCandidate candidate, out ISearchExpression? nextSearchExpression);
+
+    /// <summary>
+    ///     Encodes the literal keys of this step and of every step below it.
+    ///     Called by <see cref="SearchExpressionCompilation" />, never during matching.
+    /// </summary>
+    void ReEncode(Encoding encoding);
+}
+
+/// <summary>
+///     A node the query is tested against: its raw key and its position in the parent.
+///     The key stays undecoded, so a rejected key never becomes a string.
+/// </summary>
+public readonly ref struct MatchCandidate
+{
+    /// <summary>Undecoded key of the node. Empty for list items.</summary>
+    public readonly ReadOnlySpan<byte> Key;
+
+    /// <summary>Position of the node among its siblings, counted from 0.</summary>
+    public readonly int Index;
+
+    /// <summary>A list item, which has a position but no key.</summary>
+    public MatchCandidate(int index)
+    {
+        Key = default;
+        Index = index;
+    }
+
+    /// <summary>A dictionary entry, which has both a key and a position.</summary>
+    public MatchCandidate(int index, ReadOnlySpan<byte> key)
+    {
+        Key = key;
+        Index = index;
+    }
+}