Fix tests, parse delete statements

sqlparser/lib/src/ast/ast.dart

@@ -18,6 +18,7 @@ part 'expressions/simple.dart';
 part 'expressions/subquery.dart';
 part 'expressions/variables.dart';
 
+part 'statements/delete.dart';
 part 'statements/select.dart';
 part 'statements/statement.dart';
 
@@ -122,6 +123,7 @@ abstract class AstNode {
 abstract class AstVisitor<T> {
   T visitSelectStatement(SelectStatement e);
   T visitResultColumn(ResultColumn e);
+  T visitDeleteStatement(DeleteStatement e);
 
   T visitOrderBy(OrderBy e);
   T visitOrderingTerm(OrderingTerm e);
@@ -204,6 +206,9 @@ class RecursiveVisitor<T> extends AstVisitor<T> {
   @override
   T visitSelectStatement(SelectStatement e) => visitChildren(e);
 
+  @override
+  T visitDeleteStatement(DeleteStatement e) => visitChildren(e);
+
   @override
   T visitUnaryExpression(UnaryExpression e) => visitChildren(e);
 

sqlparser/lib/src/ast/statements/delete.dart

@@ -0,0 +1,17 @@
+part of '../ast.dart';
+
+class DeleteStatement extends Statement {
+  final TableReference from;
+  final Expression where;
+
+  DeleteStatement({@required this.from, this.where});
+
+  @override
+  T accept<T>(AstVisitor<T> visitor) => visitor.visitDeleteStatement(this);
+
+  @override
+  Iterable<AstNode> get childNodes => [from, if (where != null) where];
+
+  @override
+  bool contentEquals(DeleteStatement other) => true;
+}

sqlparser/lib/src/reader/parser/parser.dart

@@ -102,7 +102,8 @@ class Parser {
   }
 
   Statement statement() {
-    final stmt = select();
+    final stmt = select() ?? _deleteStmt();
+
     _matchOne(TokenType.semicolon);
     return stmt;
   }
@@ -218,12 +219,9 @@ class Parser {
   TableOrSubquery _tableOrSubquery() {
     //  this is what we're parsing: https://www.sqlite.org/syntax/table-or-subquery.html
     // we currently only support regular tables and nested selects
-    if (_matchOne(TokenType.identifier)) {
-      // ignore the schema name, it's not supported. Besides that, we're on the
-      // first branch in the diagram here
-      final tableName = (_previous as IdentifierToken).identifier;
-      final alias = _as();
-      return TableReference(tableName, alias?.identifier);
+    final tableRef = _tableReference();
+    if (tableRef != null) {
+      return tableRef;
     } else if (_matchOne(TokenType.leftParen)) {
       final innerStmt = select();
       _consume(TokenType.rightParen,
@@ -237,6 +235,17 @@ class Parser {
     _error('Expected a table name or a nested select statement');
   }
 
+  TableReference _tableReference() {
+    if (_matchOne(TokenType.identifier)) {
+      // ignore the schema name, it's not supported. Besides that, we're on the
+      // first branch in the diagram here
+      final tableName = (_previous as IdentifierToken).identifier;
+      final alias = _as();
+      return TableReference(tableName, alias?.identifier);
+    }
+    return null;
+  }
+
   JoinClause _joinClause(TableOrSubquery start) {
     var operator = _parseJoinOperatorNoComma();
     if (operator == null) {
@@ -375,7 +384,7 @@ class Parser {
   /// Parses a [Limit] clause, or returns null if there is no limit token after
   /// the current position.
   Limit _limit() {
-    if (!_match(const [TokenType.limit])) return null;
+    if (!_matchOne(TokenType.limit)) return null;
 
     final count = expression();
     Token offsetSep;
@@ -389,6 +398,23 @@ class Parser {
     return Limit(count: count, offsetSeparator: offsetSep, offset: offset);
   }
 
+  DeleteStatement _deleteStmt() {
+    if (!_matchOne(TokenType.delete)) return null;
+    _consume(TokenType.from, 'Expected a FROM here');
+
+    final table = _tableReference();
+    Expression where;
+    if (table == null) {
+      _error('Expected a table reference');
+    }
+
+    if (_matchOne(TokenType.where)) {
+      where = expression();
+    }
+
+    return DeleteStatement(from: table, where: where);
+  }
+
   /* We parse expressions here.
   * Operators have the following precedence:
   *  - + ~ NOT (unary)

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

@@ -141,9 +141,10 @@ class Scanner {
           _numeric(char);
         } else if (canStartColumnName(char)) {
           _identifier();
+        } else {
+          errors.add(TokenizerError(
+              'Unexpected character.', SourceLocation(_currentOffset)));
         }
-        errors.add(TokenizerError(
-            'Unexpected character.', SourceLocation(_currentOffset)));
         break;
     }
   }

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

@@ -52,6 +52,7 @@ enum TokenType {
   identifier,
 
   select,
+  delete,
   distinct,
   all,
   from,
@@ -94,6 +95,7 @@ const Map<String, TokenType> keywords = {
   'AND': TokenType.and,
   'OR': TokenType.or,
   'BETWEEN': TokenType.between,
+  'DELETE': TokenType.delete,
   'FROM': TokenType.from,
   'NATURAL': TokenType.natural,
   'LEFT': TokenType.leftParen,

sqlparser/test/parser/delete_test.dart

@@ -0,0 +1,27 @@
+import 'package:sqlparser/src/reader/tokenizer/token.dart';
+import 'package:test/test.dart';
+import 'package:sqlparser/sqlparser.dart';
+import 'package:sqlparser/src/utils/ast_equality.dart';
+
+import 'utils.dart';
+
+void main() {
+  test('parses delete statements', () {
+    final parsed = SqlEngine().parse('DELETE FROM table WHERE id = 5').rootNode;
+
+    enforceEqual(
+      parsed,
+      DeleteStatement(
+        from: TableReference('table', null),
+        where: BinaryExpression(
+          Reference(columnName: 'id'),
+          token(TokenType.equal),
+          NumericLiteral(
+            5,
+            token(TokenType.numberLiteral),
+          ),
+        ),
+      ),
+    );
+  });
+}

sqlparser/test/parser/select/from_test.dart

@@ -16,14 +16,16 @@ void _enforceFrom(SelectStatement stmt, List<Queryable> expected) {
 void main() {
   group('from', () {
     test('a simple table', () {
-      final stmt = SqlEngine().parse('SELECT * FROM table') as SelectStatement;
+      final stmt =
+          SqlEngine().parse('SELECT * FROM table').rootNode as SelectStatement;
 
       enforceEqual(stmt.from.single, TableReference('table', null));
     });
 
     test('from more than one table', () {
-      final stmt = SqlEngine().parse('SELECT * FROM table AS test, table2')
-          as SelectStatement;
+      final stmt = SqlEngine()
+          .parse('SELECT * FROM table AS test, table2')
+          .rootNode as SelectStatement;
 
       _enforceFrom(
         stmt,
@@ -35,9 +37,10 @@ void main() {
     });
 
     test('from inner select statements', () {
-      final stmt = SqlEngine().parse(
+      final stmt = SqlEngine()
+          .parse(
               'SELECT * FROM table1, (SELECT * FROM table2 WHERE a) as "inner"')
-          as SelectStatement;
+          .rootNode as SelectStatement;
 
       _enforceFrom(
         stmt,
@@ -56,9 +59,11 @@ void main() {
     });
 
     test('from a join', () {
-      final stmt = SqlEngine().parse('SELECT * FROM table1 '
-          'INNER JOIN table2 USING (test) '
-          'LEFT OUTER JOIN table3 ON TRUE') as SelectStatement;
+      final stmt = SqlEngine()
+          .parse('SELECT * FROM table1 '
+              'INNER JOIN table2 USING (test) '
+              'LEFT OUTER JOIN table3 ON TRUE')
+          .rootNode as SelectStatement;
 
       _enforceFrom(stmt, [
         JoinClause(

sqlparser/test/parser/select/group_by_test.dart

@@ -7,9 +7,9 @@ import '../utils.dart';
 
 void main() {
   test('parses group by statements', () {
-    final stmt = SqlEngine().parse(
-            "SELECT * FROM test GROUP BY country HAVING country LIKE '%G%'")
-        as SelectStatement;
+    final stmt = SqlEngine()
+        .parse("SELECT * FROM test GROUP BY country HAVING country LIKE '%G%'")
+        .rootNode as SelectStatement;
 
     return enforceEqual(
       stmt.groupBy,

sqlparser/test/parser/select/limit_test.dart

@@ -8,8 +8,9 @@ import '../utils.dart';
 void main() {
   group('limit clauses', () {
     test('with just a limit', () {
-      final select = SqlEngine().parse('SELECT * FROM test LIMIT 5 * 3')
-          as SelectStatement;
+      final select = SqlEngine()
+          .parse('SELECT * FROM test LIMIT 5 * 3')
+          .rootNode as SelectStatement;
 
       enforceEqual(
         select.limit,
@@ -24,8 +25,9 @@ void main() {
     });
 
     test('with offset', () {
-      final select = SqlEngine().parse('SELECT * FROM test LIMIT 10 OFFSET 2')
-          as SelectStatement;
+      final select = SqlEngine()
+          .parse('SELECT * FROM test LIMIT 10 OFFSET 2')
+          .rootNode as SelectStatement;
 
       enforceEqual(
         select.limit,
@@ -38,8 +40,9 @@ void main() {
     });
 
     test('with offset as comma', () {
-      final select = SqlEngine().parse('SELECT * FROM test LIMIT 10, 2')
-          as SelectStatement;
+      final select = SqlEngine()
+          .parse('SELECT * FROM test LIMIT 10, 2')
+          .rootNode as SelectStatement;
 
       enforceEqual(
         select.limit,

sqlparser/test/parser/select/order_by_test.dart

@@ -7,8 +7,9 @@ import '../utils.dart';
 
 void main() {
   test('parses order by clauses', () {
-    final parsed = SqlEngine().parse('SELECT * FROM table ORDER BY -a, b DESC')
-        as SelectStatement;
+    final parsed = SqlEngine()
+        .parse('SELECT * FROM table ORDER BY -a, b DESC')
+        .rootNode as SelectStatement;
 
     enforceEqual(
       parsed.orderBy,