ANTLR Parser Java API

Q

Where is ANTLR API for Java integration?

✍: FYIcenter

A

ANTLR API for Java is available at https://www.antlr.org/api/Java/.

To integrate the lexer and parser generated from ANTLR into your Java application, you can follow these steps:

1. Create a character stream (org.antlr.v4.runtime.CharStream) object from the your source code string to be parsed with the org.antlr.v4.runtime.CharStreams.fromString() method. For example:

CharStream stream = CharStreams.fromString("x = a");

2. Create your own lexer object from the character stream. For example:

arithmeticLexer lexer = new arithmeticLexer(stream);

3. Create a token stream (org.antlr.v4.runtime.CommonTokenStream) object from your lexer. For example:

CommonTokenStream tokens = new CommonTokenStream(lexer);

4. Create your own parser object from the token stream. For example:

arithmeticParser parser = new arithmeticParser(tokens);

5. Create a syntax tree (org.antlr.v4.runtime.tree.ParseTree) object by calling the grammar rule as a parser method. For example:

ParseTree tree = parser.equation();

6. Dump the syntax tree in LISP style. For example:

System.out.println(tree.toStringTree(parser));

If there is any syntax error in the source code, the parser.equation() method will generated error messages to the console.

 

ANTLR "Arithmeic" Grammar Java Test

ANTLR "Arithmetic" Grammar - Graphical Output

ANTLR Commands and Examples

⇑⇑ FAQ for ANTLR Parser Generator

2020-12-26, 6500👍, 0💬