Add SQL RETURN statements

db/db.go

@@ -285,7 +285,12 @@ func (e *executor) execute(quit <-chan bool, send chan<- *Response) {
 			// the end of the transaction.
 
 			if txn != nil {
+				switch stm.(type) {
+				case *sql.ReturnStatement:
+					buf = clear(buf, rsp)
+				default:
 					buf = append(buf, rsp)
+				}
 				continue
 			}
 
@@ -333,6 +338,8 @@ func (e *executor) operate(txn kvs.TX, ast sql.Statement) (res []interface{}, er
 
 	case *sql.LetStatement:
 		res, err = e.executeLetStatement(txn, stm)
+	case *sql.ReturnStatement:
+		res, err = e.executeReturnStatement(txn, stm)
 
 	case *sql.SelectStatement:
 		res, err = e.executeSelectStatement(txn, stm)

db/return.go

@@ -0,0 +1,37 @@
+// Copyright © 2016 Abcum Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package db
+
+import (
+	"github.com/abcum/surreal/kvs"
+	"github.com/abcum/surreal/sql"
+)
+
+func (e *executor) executeReturnStatement(txn kvs.TX, ast *sql.ReturnStatement) (out []interface{}, err error) {
+
+	for _, w := range ast.What {
+
+		switch what := w.(type) {
+		default:
+			out = append(out, what)
+		case *sql.Param:
+			out = append(out, e.ctx.Get(what.ID).Data())
+		}
+
+	}
+
+	return
+
+}

sql/return.go

@@ -0,0 +1,48 @@
+// Copyright © 2016 Abcum Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sql
+
+func (p *parser) parseReturnStatement() (stmt *ReturnStatement, err error) {
+
+	stmt = &ReturnStatement{}
+
+	for {
+
+		tok, lit, err := p.shouldBe(NULL, NOW, DATE, TIME, TRUE, FALSE, STRING, NUMBER, DOUBLE, PARAM)
+		if err != nil {
+			return nil, err
+		}
+
+		val, err := p.declare(tok, lit)
+		if err != nil {
+			return nil, err
+		}
+
+		stmt.What = append(stmt.What, val)
+
+		// If the next token is not a comma then break the loop.
+		if _, _, exi := p.mightBe(COMMA); !exi {
+			break
+		}
+
+	}
+
+	if _, _, err = p.shouldBe(EOF, SEMICOLON); err != nil {
+		return nil, err
+	}
+
+	return
+
+}