在 ANTLR 解析树中存储行号 [英] Storing line number in ANTLR Parse Tree

问题描述

有没有办法使用 ANTLR 4 在创建的解析树中存储行号?我遇到了 这篇 文章，它确实做到了，但我认为它适用于较旧的 ANTLR 版本，因为

Is there any way of storing line numbers in the created parse tree, using ANTLR 4? I came across this article, which does it but I think it's for older ANTLR version, because

parser.setASTFactory(工厂);

parser.setASTFactory(factory);

它似乎不适用于 ANTLR 4.我正在考虑像

It does not seem to be applicable to ANTLR 4. I am thinking of having something like

treenode.getLine()

treenode.getLine()

，就像我们可以有

treenode.getChild()

treenode.getChild()

推荐答案

使用 Antlr4，您通常可以实现侦听器或访问者.

With Antlr4, you normally implement either a listener or a visitor.

两者都为您提供了一个上下文，您可以在其中找到令牌的位置.

Both give you a context where you find the location of the tokens.

例如(对于访问者)，我想保留由大写标识符(我的令牌定义中的 UCASE_ID)定义的分配位置.

For example (with a visitor), I want to keep the location of an assignment defined by a Uppercase identifier (UCASE_ID in my token definition).

您感兴趣的是...

ctx.UCASE_ID().getSymbol().getLine()

访客看起来像......

The visitor looks like ...

static class TypeAssignmentVisitor extends ASNBaseVisitor<TypeAssignment> {
    @Override
    public TypeAssignment visitTypeAssignment(TypeAssignmentContext ctx) {
        String reference = ctx.UCASE_ID().getText();
        int line = ctx.UCASE_ID().getSymbol().getLine();
        int column = ctx.UCASE_ID().getSymbol().getCharPositionInLine()+1;

        Type type = ctx.type().accept(new TypeVisitor());
        TypeAssignment typeAssignment = new TypeAssignment();
        typeAssignment.setReference(reference);
        typeAssignment.setReferenceToken(new Token(ctx.UCASE_ID().getSymbol().getLine(), ctx.UCASE_ID().getSymbol().getCharPositionInLine()+1));
        typeAssignment.setType(type);
        return typeAssignment;
    }
}

我是 Antlr4 的新手，发现这对开始使用听众和访问者很有用...https://github.com/JakubDziworski/AntlrListenerVisitorComparison/

I was new to Antlr4 and found this useful to get started with listeners and visitors ... https://github.com/JakubDziworski/AntlrListenerVisitorComparison/

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