added rtree support

drift_dev/lib/src/analyzer/options.dart

@@ -275,4 +275,8 @@ enum SqlModule {
   ///
   /// [math funs]: https://www.sqlite.org/lang_mathfunc.html
   math,
+
+  /// Enables support for the rtree module and its functions when parsing sql
+  /// queries.
+  rtree,
 }

drift_dev/lib/src/analyzer/options.g.dart

@@ -140,6 +140,7 @@ const _$SqlModuleEnumMap = {
   SqlModule.fts5: 'fts5',
   SqlModule.moor_ffi: 'moor_ffi',
   SqlModule.math: 'math',
+  SqlModule.rtree: 'rtree',
 };
 
 DialectOptions _$DialectOptionsFromJson(Map json) => $checkedCreate(

drift_dev/lib/src/analyzer/session.dart

@@ -45,6 +45,7 @@ class MoorSession {
         if (options.hasModule(SqlModule.json1)) const Json1Extension(),
         if (options.hasModule(SqlModule.moor_ffi)) const MoorFfiExtension(),
         if (options.hasModule(SqlModule.math)) const BuiltInMathExtension(),
+        if (options.hasModule(SqlModule.rtree)) const RTreeExtension(),
       ],
       version: options.sqliteVersion,
     );

sqlparser/lib/sqlparser.dart

@@ -7,6 +7,7 @@ export 'src/ast/ast.dart';
 export 'src/engine/module/fts5.dart' show Fts5Extension;
 export 'src/engine/module/json1.dart' show Json1Extension;
 export 'src/engine/module/math.dart' show BuiltInMathExtension;
+export 'src/engine/module/rtree.dart' show RTreeExtension;
 export 'src/engine/module/module.dart';
 export 'src/engine/options.dart';
 export 'src/engine/sql_engine.dart';

sqlparser/lib/src/engine/module/rtree.dart

@@ -0,0 +1,39 @@
+import 'package:sqlparser/sqlparser.dart';
+
+class RTreeExtension implements Extension {
+  const RTreeExtension();
+
+  @override
+  void register(SqlEngine engine) {
+    engine.registerModule(_RTreeModule());
+  }
+}
+
+class _RTreeModule extends Module {
+  _RTreeModule() : super('rtree');
+
+  @override
+  Table parseTable(CreateVirtualTableStatement stmt) {
+    final columnNames = stmt.argumentContent;
+
+    if (columnNames.length < 3 || columnNames.length > 11) {
+      throw ArgumentError(
+          'An rtree virtual table is supposed to have between 3 and 11 columns');
+    }
+
+    if (columnNames.length.isEven) {
+      throw ArgumentError(
+          'The rtree has not been initialized with a proper dimension. '
+          'Required is an index, follwoed by a even number of min/max pairs');
+    }
+
+    return Table(name: stmt.tableName, resolvedColumns: [
+      for (final columnName in columnNames)
+        //First column is always an integer primary key
+        //followed by n floating point values
+        (columnName == columnNames.first)
+            ? TableColumn(columnName, const ResolvedType(type: BasicType.int))
+            : TableColumn(columnName, const ResolvedType(type: BasicType.real))
+    ]);
+  }
+}

sqlparser/test/engine/module/rtree_test.dart

@@ -0,0 +1,65 @@
+import 'package:sqlparser/sqlparser.dart';
+import 'package:test/test.dart';
+
+final _rtreeOptions =
+    EngineOptions(enabledExtensions: const [RTreeExtension()]);
+
+void main() {
+  group('creating rtree tables', () {
+    final engine = SqlEngine(_rtreeOptions);
+
+    test('can create rtree table', () {
+      final result = engine.analyze('''
+CREATE VIRTUAL TABLE demo_index USING rtree(
+   id,              -- Integer primary key
+   minX, maxX,      -- Minimum and maximum X coordinate
+   minY, maxY       -- Minimum and maximum Y coordinate
+);''');
+
+      final table = const SchemaFromCreateTable()
+          .read(result.root as TableInducingStatement);
+
+      expect(table.name, 'demo_index');
+      final columns = table.resultColumns;
+      expect(columns, hasLength(5));
+      expect(columns.first.type.type, equals(BasicType.int));
+      expect(columns.last.type.type, equals(BasicType.real));
+    });
+  });
+
+  group('type inference for function arguments', () {
+    late SqlEngine engine;
+    setUp(() {
+      engine = SqlEngine(_rtreeOptions);
+      // add an fts5 table for the following queries
+      final result = engine.analyze('''
+CREATE VIRTUAL TABLE demo_index USING rtree(
+   id,              -- Integer primary key
+   minX, maxX,      -- Minimum and maximum X coordinate
+   minY, maxY       -- Minimum and maximum Y coordinate
+);''');
+
+      engine.registerTable(const SchemaFromCreateTable()
+          .read(result.root as TableInducingStatement));
+    });
+
+    test('insert', () {
+      final result = engine.analyze('INSERT INTO demo_index VALUES '
+          '(28215, -80.781227, -80.604706, 35.208813, 35.297367);');
+      expect(result.errors, isEmpty);
+    });
+
+    test('select', () {
+      final result = engine.analyze('''
+SELECT A.* FROM demo_index AS A, demo_index AS B
+ WHERE A.maxX>=B.minX AND A.minX<=B.maxX
+   AND A.maxY>=B.minY AND A.minY<=B.maxY
+   AND B.id=28269;''');
+
+      final columns = (result.root as SelectStatement).resolvedColumns;
+
+      expect(result.errors, isEmpty);
+      expect(columns, hasLength(5));
+    });
+  });
+}