001/*
002 * Copyright 2002-2014 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.expression.spel;
018
019/**
020 * Captures the possible configuration settings for a compiler that can be
021 * used when evaluating expressions.
022 *
023 * @author Andy Clement
024 * @since 4.1
025 */
026public enum SpelCompilerMode {
027
028        /**
029         * The compiler is switched off; this is the default.
030         */
031        OFF,
032
033        /**
034         * In immediate mode, expressions are compiled as soon as possible (usually after 1 interpreted run).
035         * If a compiled expression fails it will throw an exception to the caller.
036         */
037        IMMEDIATE,
038
039        /**
040         * In mixed mode, expression evaluation silently switches between interpreted and compiled over time.
041         * After a number of runs the expression gets compiled. If it later fails (possibly due to inferred
042         * type information changing) then that will be caught internally and the system switches back to
043         * interpreted mode. It may subsequently compile it again later.
044         */
045        MIXED
046
047}