prompto.java.JavaStatement Maven / Gradle / Ivy

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package prompto.java;

import java.util.HashMap;
import java.util.Map;
import java.util.function.Function;

import prompto.compiler.Flags;
import prompto.compiler.MethodInfo;
import prompto.compiler.Opcode;
import prompto.compiler.ResultInfo;
import prompto.error.NativeError;
import prompto.error.PromptoError;
import prompto.error.SyntaxError;
import prompto.runtime.Context;
import prompto.runtime.VoidResult;
import prompto.type.IType;
import prompto.type.VoidType;
import prompto.utils.CodeWriter;
import prompto.utils.Logger;
import prompto.value.IValue;
import prompto.value.NullValue;

public class JavaStatement {

	static Logger logger = new Logger();
	
	JavaExpression expression;
	boolean isReturn;
	
	public JavaStatement(JavaExpression expression,boolean isReturn) {
		this.expression = expression;
		this.isReturn = isReturn;
	}

	public IType check(Context context, IType returnType) {
		IType type = expression.check(context);
		if(type instanceof JavaClassType) 
			type = ((JavaClassType)type).convertJavaClassToPromptoType(context, returnType);
		return isReturn ? type : VoidType.instance();
	}

	public IValue interpret(Context context, IType returnType) throws PromptoError {
		Object result = interpret(context); 
		if(result==null) {
			if(isReturn) {
				if(returnType==null)
					return VoidResult.instance();
				else
					return NullValue.instance();
			} else 
				return null;
		} else {	
            IType type = expression.check(context);
            if (type instanceof JavaClassType)
                return ((JavaClassType)type).convertJavaValueToPromptoValue(context, result, returnType);
            else
            	// TODO warning or exception?
            	return VoidResult.instance();
		}
	}
	
	private Object interpret(Context context) {
		// map native error to Prompto one
		try {
			return expression.interpret(context);
		} catch(Throwable t) {
			logger.error(()->"While interpreting: " + this.toString(), t);
			throw new NativeError("While interpreting: " + this.toString(), t);
		}
	}

	@Override
	public String toString() {
		return "" + (isReturn ? "return " : "") + expression.toString() + ";";
	}

	public void toDialect(CodeWriter writer) {
		if(isReturn)
			writer.append("return ");
		expression.toDialect(writer);
		writer.append(';');
	}

	static Map, Function> resultConsumers = createResultConsumers();
	
	private static Map, Function> createResultConsumers() {
		Map, Function> map = new HashMap<>();
		return map;
	}

	public ResultInfo compile(Context context, MethodInfo method, Flags flags) {
		ResultInfo info = expression.compile(context, method);
		if(isReturn) {
			if(info.getType()==void.class)
				throw new SyntaxError("Cannot return void!"); // TODO add a test to ensure this has been caught earlier
			info = JavaValueConverter.convertResult(method, info);
			if(!flags.isInline())
				method.addInstruction(Opcode.ARETURN);
			return info;
		} else if(info.getType()!=void.class) {
			Function consumer = resultConsumers.get(info.getType());
			if(consumer!=null)
				info = consumer.apply(method);
			else
				method.addInstruction(Opcode.POP);
			return new ResultInfo(void.class);
		} else
			return info;
	}


}