import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.misc.NotNull;
import org.antlr.v4.runtime.tree.ErrorNode;
import org.antlr.v4.runtime.tree.TerminalNode;
import org.antlr.v4.runtime.Token;
import org.antlr.v4.runtime.tree.ParseTreeProperty;
import java.util.*;
/**
* A listener mechanism for creating and naming the klasses in the symbol
* table. When the ParseTreeWalker visits a node in the parse tree,
* it calls the enterRule method associated with that node.
* It then does the same thing to all children of that node.
* When the ParseTreeWalker exits a node, it calls the exitRule
* method associated with that node.
*
* This class is listening for the ParseTreeWalker to visit each node.
* When the ParseTreeWalker enters a class declaration, the
* enterClassDeclaration method is called. All children are visited
* in the same manner and then the exitClassDeclaration method is called.
*
* This results in an in-order traversal of the parse tree.
*/
public class ClassNamer extends MinijavaBaseListener {
//The symbol-table collection of classes
private Map klasses;
//The parser that generated the parse tree that this listener
//is attached to. Useful for reporting the line number
//and column number of the offending token.
private MinijavaParser parser;
/**
* [ClassNamer description]
* @param klasses The symbol-table collection of classes
* @param parser The parser that generated the parse tree
* that this listener is attached to.
*/
public ClassNamer(Map klasses, MinijavaParser parser){
this.klasses = klasses;
this.parser = parser;
}
/**
* Creates a klass in the symbol-table with the name derived from the
* context. Prints a duplicateClassError if the symbol-table already
* contains a klass with that name.
*/
@Override public void enterClassDeclaration(@NotNull MinijavaParser.ClassDeclarationContext ctx) {
Klass currentKlass = new Klass(ctx.Identifier(0).getText());
if(klasses.put(currentKlass.getScopeName(), currentKlass)!=null){
ErrorPrinter.printDuplicateClassError(parser, ctx.Identifier(0).getSymbol(), currentKlass.getScopeName());
}
}
/**
* Adds the main class along with the primitive types to the symbol-table
*/
@Override public void enterMainClass(@NotNull MinijavaParser.MainClassContext ctx) {
Klass currentKlass;
currentKlass = new Klass("int[]");
klasses.put(currentKlass.getScopeName(),currentKlass);
currentKlass = new Klass("int");
klasses.put(currentKlass.getScopeName(),currentKlass);
//System.out.println("Klasses.get(\"int\" = " + klasses.get("int"));
currentKlass = new Klass("boolean");
klasses.put(currentKlass.getScopeName(),currentKlass);
currentKlass = new Klass(ctx.Identifier(0).getText());
klasses.put(currentKlass.getScopeName(), currentKlass);
}
}