package org.simantics.scl.compiler.elaboration.expressions.annotations;

import org.simantics.scl.compiler.constants.StringConstant;
import org.simantics.scl.compiler.elaboration.expressions.ELiteral;
import org.simantics.scl.compiler.elaboration.expressions.EStringLiteral;
import org.simantics.scl.compiler.elaboration.expressions.EVar;
import org.simantics.scl.compiler.elaboration.expressions.Expression;

public class AnnotationUtils {
    public static String extractString(Expression expression) {
        if(expression instanceof EVar)
            return ((EVar)expression).name;
        else if(expression instanceof EStringLiteral) {
            EStringLiteral literal = (EStringLiteral)expression;
            if(literal.strings.length == 1)
                return literal.strings[0];
        }
        else if(expression instanceof ELiteral) {
            ELiteral literal = (ELiteral)expression;
            if(literal.getValue() instanceof StringConstant) {
                StringConstant constant = (StringConstant)literal.getValue();
                return constant.getValue();
            }
        }
        return null;
    }
}