Examples with IterationKind com.github.anba.es6draft.ast.LegacyComprehensionFor.IterationKind used on opensource projects

Example 1 with IterationKind

use of com.github.anba.es6draft.ast.LegacyComprehensionFor.IterationKind in project es6draft by anba.

the class ComprehensionGenerator method visit.

/**
     * Runtime Semantics: ComprehensionComponentEvaluation
     * <p>
     * ComprehensionFor : for ( ForBinding of AssignmentExpression )
     */
@Override
public Void visit(LegacyComprehensionFor node, CodeVisitor mv) {
    Jump lblTest = new Jump(), lblLoop = new Jump(), lblFail = new Jump();
    Variable<ScriptIterator<?>> iter = iterators.next();
    ValType type = expressionBoxed(node.getExpression(), mv);
    if (type != ValType.Object) {
        // fail-safe behaviour for null/undefined values in legacy comprehensions
        Jump loopstart = new Jump();
        mv.dup();
        isUndefinedOrNull(mv);
        mv.ifeq(loopstart);
        mv.pop();
        mv.goTo(lblFail);
        mv.mark(loopstart);
    }
    IterationKind iterationKind = node.getIterationKind();
    if (iterationKind == IterationKind.Enumerate || iterationKind == IterationKind.EnumerateValues) {
        // legacy generator mode, both, for-in and for-each, perform Iterate on generators
        Jump l0 = new Jump(), l1 = new Jump();
        mv.dup();
        mv.instanceOf(Types.GeneratorObject);
        mv.ifeq(l0);
        mv.dup();
        mv.checkcast(Types.GeneratorObject);
        mv.invoke(Methods.GeneratorObject_isLegacyGenerator);
        mv.ifeq(l0);
        mv.loadExecutionContext();
        mv.lineInfo(node.getExpression());
        mv.invoke(Methods.ScriptRuntime_iterate);
        mv.goTo(l1);
        mv.mark(l0);
        mv.loadExecutionContext();
        mv.lineInfo(node.getExpression());
        if (iterationKind == IterationKind.Enumerate) {
            mv.invoke(Methods.ScriptRuntime_enumerate);
        } else {
            mv.invoke(Methods.ScriptRuntime_enumerateValues);
        }
        mv.mark(l1);
    } else {
        assert iterationKind == IterationKind.Iterate;
        mv.loadExecutionContext();
        mv.lineInfo(node.getExpression());
        mv.invoke(Methods.ScriptRuntime_iterate);
    }
    mv.store(iter);
    mv.nonDestructiveGoTo(lblTest);
    mv.mark(lblLoop);
    mv.load(iter);
    mv.lineInfo(node);
    mv.invoke(Methods.Iterator_next);
    new IterationGenerator<LegacyComprehensionFor>(codegen) {

        @Override
        protected Completion iterationBody(LegacyComprehensionFor node, Variable<ScriptIterator<?>> iterator, CodeVisitor mv) {
            // stack: [nextValue] -> []
            BindingInitialization(codegen, node.getBinding(), mv);
            elements.next().accept(ComprehensionGenerator.this, mv);
            return Completion.Normal;
        }

        @Override
        protected MutableValue<Object> enterIteration(LegacyComprehensionFor node, CodeVisitor mv) {
            return mv.enterIteration();
        }

        @Override
        protected List<TempLabel> exitIteration(LegacyComprehensionFor node, CodeVisitor mv) {
            return mv.exitIteration();
        }
    }.generate(node, iter, mv);
    mv.mark(lblTest);
    mv.load(iter);
    mv.lineInfo(node);
    mv.invoke(Methods.Iterator_hasNext);
    mv.ifne(lblLoop);
    mv.mark(lblFail);
    return null;
}