Own-Programming-Language-Tutorial/src/com/annimon/ownlang/parser/ast/ForeachMapStatement.java

package com.annimon.ownlang.parser.ast;

import com.annimon.ownlang.lib.Value;
import com.annimon.ownlang.lib.Variables;
import java.util.Map;

/**
 *
 * @author aNNiMON
 */
public final class ForeachMapStatement implements Statement {
    
    public final String key, value;
    public final Expression container;
    public final Statement body;

    public ForeachMapStatement(String key, String value, Expression container, Statement body) {
        this.key = key;
        this.value = value;
        this.container = container;
        this.body = body;
    }

    @Override
    public void execute() {
        final Value previousVariableValue1 = Variables.isExists(key) ? Variables.get(key) : null;
        final Value previousVariableValue2 = Variables.isExists(value) ? Variables.get(value) : null;
        final Iterable<Map.Entry<Value, Value>> iterator = (Iterable<Map.Entry<Value, Value>>) container.eval();
        for (Map.Entry<Value, Value> entry : iterator) {
            Variables.set(key, entry.getKey());
            Variables.set(value, entry.getValue());
            try {
                body.execute();
            } catch (BreakStatement bs) {
                break;
            } catch (ContinueStatement cs) {
                // continue;
            }
        }
        // Восстанавливаем переменные
        if (previousVariableValue1 != null) {
            Variables.set(key, previousVariableValue1);
        }
        if (previousVariableValue2 != null) {
            Variables.set(value, previousVariableValue2);
        }
    }
    
    @Override
    public void accept(Visitor visitor) {
        visitor.visit(this);
    }

    @Override
    public String toString() {
        return String.format("for %s, %s : %s %s", key, value, container, body);
    }
}