add LIST parsing to the sqlparser

sqlparser/lib/src/analysis/steps/column_resolver.dart

@@ -320,6 +320,8 @@ class ColumnResolver extends RecursiveVisitor<void, void> {
         });
 
         if (target != null) resultColumn.resultSet = target.resultSet.resultSet;
+      } else if (resultColumn is NestedQueryColumn) {
+        _resolveSelect(resultColumn.select);
       }
     }
 

sqlparser/lib/src/ast/ast.dart

@@ -18,6 +18,7 @@ export 'moor/declared_statement.dart';
 export 'moor/import_statement.dart';
 export 'moor/inline_dart.dart';
 export 'moor/moor_file.dart';
+export 'moor/nested_query_column.dart';
 export 'moor/nested_star_result_column.dart';
 export 'node.dart';
 export 'statements/block.dart';

sqlparser/lib/src/ast/moor/nested_query_column.dart

@@ -0,0 +1,38 @@
+import '../../../sqlparser.dart';
+import '../ast.dart' show ResultColumn, Renamable;
+import '../node.dart';
+import '../visitor.dart';
+import 'moor_file.dart';
+
+/// A nested query column, denoted by `LIST(...)` in user queries.
+///
+/// Nested query columns take a select query and execute it for every result
+/// returned from the main query. Nested query columns can only be added to a
+/// top level select query, because the result of them can only be computed
+/// in dart.
+class NestedQueryColumn extends ResultColumn
+    implements MoorSpecificNode, Renamable, Referencable {
+  @override
+  final String? as;
+
+  SelectStatement select;
+
+  NestedQueryColumn({required this.select, this.as});
+
+  @override
+  Iterable<AstNode> get childNodes => [select];
+
+  @override
+  void transformChildren<A>(Transformer<A> transformer, A arg) {
+    select = transformer.transformChild(select, this, arg);
+  }
+
+  @override
+  R accept<A, R>(AstVisitor<A, R> visitor, A arg) {
+    return visitor.visitMoorSpecificNode(this, arg);
+  }
+
+  // idk is this required?
+  @override
+  bool get visibleToChildren => false;
+}

sqlparser/lib/src/reader/parser.dart

@@ -1933,6 +1933,34 @@ class Parser {
       _current = positionBefore;
     }
 
+    // parsing for the nested query column
+    if (enableMoorExtensions && _matchOne(TokenType.list)) {
+      final list = _previous;
+
+      _consume(
+        TokenType.leftParen,
+        'Expected opening parenthesis after LIST',
+      );
+
+      // or _fullSelect but I don't think with support is required here because
+      // with statements can be added to the main select statement
+      final statement = select();
+      if (statement == null || statement is! SelectStatement) {
+        _error(
+          'Expected a select statement but found ${statement?.toString()}',
+        );
+      }
+
+      _consume(
+        TokenType.rightParen,
+        'Expected closing parenthesis to finish LIST expression',
+      );
+
+      final as = _as();
+      return NestedQueryColumn(select: statement, as: as?.identifier)
+        ..setSpan(list, _previous);
+    }
+
     final tokenBefore = _peek;
 
     final expr = expression();

sqlparser/lib/src/reader/tokenizer/token.dart

@@ -218,6 +218,7 @@ enum TokenType {
   import,
   json,
   required,
+  list,
 
   /// A `**` token. This is only scanned when scanning for moor tokens.
   doubleStar,
@@ -413,6 +414,7 @@ const Map<String, TokenType> moorKeywords = {
   'JSON': TokenType.json,
   'MAPPED': TokenType.mapped,
   'REQUIRED': TokenType.required,
+  'LIST': TokenType.list,
 };
 
 /// A set of [TokenType]s that can be parsed as an identifier.

sqlparser/lib/src/utils/ast_equality.dart

@@ -443,6 +443,12 @@ class EqualityEnforcingVisitor implements AstVisitor<void, void> {
     _checkChildren(e);
   }
 
+  void visitMoorNestedQueryColumn(NestedQueryColumn e, void arg) {
+    final current = _currentAs<NestedQueryColumn>(e);
+    _assert(current.as == e.as, e);
+    _checkChildren(e);
+  }
+
   @override
   void visitMoorSpecificNode(MoorSpecificNode e, void arg) {
     if (e is DartPlaceholder) {
@@ -459,6 +465,8 @@ class EqualityEnforcingVisitor implements AstVisitor<void, void> {
       return visitMoorStatementParameter(e, arg);
     } else if (e is MoorTableName) {
       return visitMoorTableName(e, arg);
+    } else if (e is NestedQueryColumn) {
+      return visitMoorNestedQueryColumn(e, arg);
     }
   }
 

sqlparser/test/parser/select/nested_query_test.dart

@@ -0,0 +1,42 @@
+import 'package:sqlparser/sqlparser.dart';
+import 'package:sqlparser/src/utils/ast_equality.dart';
+import 'package:test/test.dart';
+
+import '../utils.dart';
+
+void main() {
+  test('parses nested query statements', () {
+    final stmt = SqlEngine(EngineOptions(useMoorExtensions: true))
+        .parse('SELECT LIST(SELECT * FROM test) FROM test')
+        .rootNode as SelectStatement;
+
+    enforceHasSpan(stmt);
+    return enforceEqual(
+      stmt.columns[0],
+      NestedQueryColumn(
+        select: SelectStatement(
+          columns: [StarResultColumn(null)],
+          from: TableReference('test'),
+        ),
+      ),
+    );
+  });
+
+  test('parses nested query statements with as', () {
+    final stmt = SqlEngine(EngineOptions(useMoorExtensions: true))
+        .parse('SELECT LIST(SELECT * FROM test) AS newname FROM test')
+        .rootNode as SelectStatement;
+
+    enforceHasSpan(stmt);
+    return enforceEqual(
+      stmt.columns[0],
+      NestedQueryColumn(
+        as: 'newname',
+        select: SelectStatement(
+          columns: [StarResultColumn(null)],
+          from: TableReference('test'),
+        ),
+      ),
+    );
+  });
+}