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

问题描述

是否可以使用ANTLR 4在创建的分析树中存储行号?我遇到了这篇文章可以做到这一点，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(factory);

parser.setASTFactory(factory);

它似乎不适用于ANTLR 4. 我正在考虑使用

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

treenode.getLine()

treenode.getLine()

，就像我们可以拥有的

treenode.getChild()

treenode.getChild()

推荐答案

使用Antlr4，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(与访客一起)，我想保留由大写标识符(令牌定义中的UCASE_ID)定义的分配的位置.

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...

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，他发现这对于开始侦听器和访问者很有用... 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/

这篇关于在ANTLR解析树中存储行号的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！