com.alibaba.qlexpress4.runtime.instruction.ForEachInstruction Maven / Gradle / Ivy

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package com.alibaba.qlexpress4.runtime.instruction;

import com.alibaba.qlexpress4.QLOptions;
import com.alibaba.qlexpress4.exception.ErrorReporter;
import com.alibaba.qlexpress4.exception.QLErrorCodes;
import com.alibaba.qlexpress4.exception.QLRuntimeException;
import com.alibaba.qlexpress4.exception.UserDefineException;
import com.alibaba.qlexpress4.runtime.*;
import com.alibaba.qlexpress4.utils.PrintlnUtils;

import java.lang.reflect.Array;
import java.text.MessageFormat;
import java.util.Iterator;
import java.util.function.Consumer;

/**
 * Operation: process each element in iterable object on top of stack,
 * Input: 1
 * Output: 0
 *
 * Author: DQinYuan
 */
public class ForEachInstruction extends QLInstruction {

    private final QLambdaDefinition body;

    private final ErrorReporter targetErrorReporter;

    private final Class itCls;

    public ForEachInstruction(ErrorReporter errorReporter, QLambdaDefinition body,
            Class itCls, ErrorReporter targetErrorReporter) {
        super(errorReporter);
        this.body = body;
        this.itCls = itCls;
        this.targetErrorReporter = targetErrorReporter;
    }

    @Override
    public QResult execute(QContext qContext, QLOptions qlOptions) {
        Object mayBeIterable = qContext.pop().get();
        if (mayBeIterable != null && mayBeIterable.getClass().isArray()) {
            mayBeIterable = new ReflectArrayIterable(mayBeIterable);
        } else if (!(mayBeIterable instanceof Iterable)) {
            throw targetErrorReporter.report(QLErrorCodes.FOR_EACH_ITERABLE_REQUIRED.name(),
                    QLErrorCodes.FOR_EACH_ITERABLE_REQUIRED.getErrorMsg());
        }
        Iterable iterable = (Iterable) mayBeIterable;
        QLambda bodyLambda = body.toLambda(qContext, qlOptions, true);
        forEachBody:
        for (Object item : iterable) {
            try {
                QResult bodyResult = bodyLambda.call(item);
                switch (bodyResult.getResultType()) {
                    case RETURN:
                        return bodyResult;
                    case BREAK:
                        break forEachBody;
                }
            } catch (UserDefineException e) {
                throw errorReporter.reportFormat(QLErrorCodes.FOR_EACH_TYPE_MISMATCH.name(),
                        QLErrorCodes.FOR_EACH_TYPE_MISMATCH.getErrorMsg(), itCls.getName(),
                        item == null? "null": item.getClass().getName());
            } catch (Throwable t) {
                if (t instanceof QLRuntimeException) {
                    throw (QLRuntimeException) t;
                }
                // should not run there
                throw errorReporter.report(QLErrorCodes.FOR_EACH_UNKNOWN_ERROR.name(),
                        QLErrorCodes.FOR_EACH_UNKNOWN_ERROR.getErrorMsg());
            }
        }
        return QResult.NEXT_INSTRUCTION;
    }

    @Override
    public int stackInput() {
        return 1;
    }

    @Override
    public int stackOutput() {
        return 0;
    }

    @Override
    public void println(int index, int depth, Consumer debug) {
        PrintlnUtils.printlnByCurDepth(depth, index + ": ForEach", debug);
        body.println(depth+1, debug);
    }

    private static class ReflectArrayIterable implements Iterable