如何在ANTLR4中生成AST? [英] How to generate AST in ANTLR4?

问题描述

我正在做一个项目，在该项目中我必须为给定的程序生成抽象语法树.这里的程序可以是任何主流编程语言.在 ANTLR4 中生成 AST 的标准方法应该是什么?我只知道 ANTLR4 的基础知识，并且能够为给定程序生成解析树.

I'm working on a project in which I have to generate Abstract Syntax Tree for a given program. Here program can be in any mainstream programming languages. What should be the standard way of generating AST in ANTLR4? I know only basics of ANTLR4 and I'm able to generate Parse tree for a given program.

推荐答案

ANTLR 4 自动生成解析树，而不是依赖手动构建的 AST.这一决定是在观察了多年开发后做出的，先前的方法遇到了极端的可维护性挑战，尤其是在涉及多个树解析器时.

ANTLR 4 automatically generates parse trees instead of relying on manually-structured ASTs. This decision was made after observing years of development with prior approaches encountering extreme maintainability challenges, especially when multiple tree parsers were involved.

如果您需要源代码的抽象表示，您应该创建一个对象模型来准确表示您的语言中的构造，而不是依赖弱类型和一般非结构化的 AST 节点.然后，您可以遍历解析树而不是 AST 来创建对象模型.

If you need an abstract representation of your source code, you should create an object model that accurately represents the constructs in your language, rather than rely on weakly typed and generally unstructured AST nodes. You then walk the parse trees instead of ASTs to create your object model.

我不建议在任何新项目中使用 ANTLR 3.

I would not advise going with ANTLR 3 for any new project.

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