Mercurial > hg > graal-jvmci-8
view graal/com.oracle.truffle.api/src/com/oracle/truffle/api/TruffleLanguage.java @ 21468:99942eac9c6d
Introducing TruffleVM - a central place to invoke code in any registered TruffleLanguage.
author | Jaroslav Tulach <jaroslav.tulach@oracle.com> |
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date | Fri, 22 May 2015 13:41:10 +0200 |
parents | |
children | bb51b9a142b3 |
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/* * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.oracle.truffle.api; import com.oracle.truffle.api.impl.Accessor; import com.oracle.truffle.api.source.Source; import com.oracle.truffle.api.vm.TruffleVM; import com.oracle.truffle.api.vm.TruffleVM.Language; import java.io.IOException; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; /** * An entry point for everyone who wants to implement a Truffle based language. By providing * implementation of this type and registering it using {@link Registration} annotation, your * language becomes accessible to users of the {@link TruffleVM Truffle virtual machine} - all they * will need to do is to include your JAR into their application and all the Truffle goodies (multi * language support, multi tennat hosting, debugging, etc.) will be made available to them. */ public abstract class TruffleLanguage { private Env env; /** * The annotation to use to register your language to the {@link TruffleVM Truffle} system. By * annotating your implementation of {@link TruffleLanguage} by this annotation you are just a * <em>one JAR drop to the classpath</em> away from your users. Once they include your JAR in * their application, your language will be available to the {@link TruffleVM Truffle virtual * machine}. */ @Retention(RetentionPolicy.SOURCE) @Target(ElementType.TYPE) public @interface Registration { /** * Unique name of your language. This name will be exposed to users via the * {@link Language#getName()} getter. * * @return identifier of your language */ String name(); /** * List of mimetypes associated with your language. Users will use them (directly or * inderectly) when {@link TruffleVM#eval(java.lang.String, java.lang.String) executing} * their code snippets or their {@link TruffleVM#eval(java.net.URI) files}. * * @return array of mime types assigned to your language files */ String[] mimeType(); } @SuppressWarnings("all") void attachEnv(Env env) { this.env = env; } protected final Env env() { if (this.env == null) { throw new NullPointerException("Accessing env before initialization is finished"); } return this.env; } protected abstract Object eval(Source code) throws IOException; /** * Called when some other language is seeking for a global symbol. This method is supposed to do * lazy binding, e.g. there is no need to export symbols in advance, it is fine to wait until * somebody asks for it (by calling this method). * <p> * The exported object can either be <code>TruffleObject</code> (e.g. a native object from the * other language) to support interoperability between languages or one of Java primitive * wrappers ( {@link Integer}, {@link Double}, {@link Short}, etc.). * * @param globalName the name of the global symbol to find * @return an exported object or <code>null</code>, if the symbol does not represent anything * meaningful in this language */ protected abstract Object findExportedSymbol(String globalName); /** * Returns global object for the language. * <p> * The object is expected to be <code>TruffleObject</code> (e.g. a native object from the other * language) but technically it can be one of Java primitive wrappers ({@link Integer}, * {@link Double}, {@link Short}, etc.). * * @return the global object or <code>null</code> if the language does not support such concept */ protected abstract Object getLanguageGlobal(); /** * Checks whether the object is provided by this language. * * @param object the object to check * @return <code>true</code> if this language can deal with such object in native way */ protected abstract boolean isObjectOfLanguage(Object object); /** * Represents execution environment of the {@link TruffleLanguage}. Each active * {@link TruffleLanguage} receives instance of the environment before any code is executed upon * it. The environment has knowledge of all active languages and can exchange symbols between * them. */ public static final class Env { private final TruffleVM vm; private final TruffleLanguage lang; Env(TruffleVM vm, TruffleLanguage lang) { this.vm = vm; this.lang = lang; } /** * Asks the environment to go through other registered languages and find whether they * export global symbol of specified name. The expected return type is either * <code>TruffleObject</code>, or one of wrappers of Java primitive types ({@link Integer}, * {@link Double}). * * @param globalName the name of the symbol to search for * @return object representing the symbol or <code>null</code> */ public Object importSymbol(String globalName) { return API.importSymbol(vm, lang, globalName); } } private static final AccessAPI API = new AccessAPI(); private static final class AccessAPI extends Accessor { @Override protected Env attachEnv(TruffleVM vm, TruffleLanguage l) { Env env = new Env(vm, l); l.attachEnv(env); return env; } @Override public Object importSymbol(TruffleVM vm, TruffleLanguage queryingLang, String globalName) { return super.importSymbol(vm, queryingLang, globalName); } @Override protected Object eval(TruffleLanguage l, Source s) throws IOException { return l.eval(s); } @Override protected Object findExportedSymbol(TruffleLanguage l, String globalName) { return l.findExportedSymbol(globalName); } @Override protected Object languageGlobal(TruffleLanguage l) { return l.getLanguageGlobal(); } } }