将 Antlr 语法树转换为有用的对象

发布于 2024-08-20 12:47:07 字数 1555 浏览 5 评论 0原文

我目前正在考虑如何最好地获取使用 Antlr 生成的 AST，并将其转换为可以在我的程序中使用的有用对象。

我语法的目的（除了学习之外）是创建一种可执行（运行时解释的）语言。

例如，我将如何获取属性子树并实例化特定的属性类。例如，

以下代码用我的语言：

Print(message:"Hello stackoverflow")

将产生以下 AST：

我目前的想法是工厂类可以读取树，提取名称（message）和类型（STRING）value（“Hello stackoverflow”）”）。现在，知道了类型，我可以实例化正确的类（例如 StringAttribute 类）并传入所需的属性数据 - name 和 value。

相同的方法可用于定义工厂，提取定义名称 (Print)，实例化 Print 类，然后传入从属性工厂生成的属性。

对于更复杂的程序，事情确实会变得更复杂：

Program(args:[1,2,3,4,5])
{
    If(isTrue:IsInArray(array:{Program.args} value:5))
    {
        Then {
            Print(message:"5 is in the array")
        } Else {
            Print(message:"More complex " + "message")
        }
    }
}

非常欢迎任何/所有帮助或想法。非常感谢。

我以前提出的相关问题（可能有用）：

原文

I'm currently pondering how best to take an AST generated using Antlr and convert it into useful objects which I can use in my program.

The purpose of my grammar (apart from learning) is to create an executable (runtime interpretted) language.

For example, how would I take an attribute sub-tree and have a specific Attribute class instanciated. E.g.

The following code in my language:

Print(message:"Hello stackoverflow")

would product the following AST:

My current line of thinking is that a factory class could read the tree, pull out the name (message), and type(STRING) value("Hello stackoverflow"). Now, knowing the type I could instanciate the correct class (e.g. A StringAttribute class) and pass in the required attribute data - the name and value.

The same approach could be used for a definition factory, pulling out the definition name (Print), instanciating the Print class, and then passing in the attributes generated from the attribute factory.

Things do get a bit more complicated with a more complicated program:

Program(args:[1,2,3,4,5])
{
    If(isTrue:IsInArray(array:{Program.args} value:5))
    {
        Then {
            Print(message:"5 is in the array")
        } Else {
            Print(message:"More complex " + "message")
        }
    }
}