for – if

gensrc.java

package tmp;

final class forIf_ {
    
    private forIf_() {
    }
    
    static .ceylon.language.Iterable<? extends .java.lang.Object, ? extends .java.lang.Object> forIf(final .ceylon.language.Iterable<? extends .ceylon.language.String, ? extends .java.lang.Object> x) {
        return new .com.redhat.ceylon.compiler.java.language.AbstractIterable<.ceylon.language.String, .java.lang.Object>(.com.redhat.ceylon.compiler.java.runtime.model.TypeDescriptor.union(.ceylon.language.Null.$TypeDescriptor$, .ceylon.language.String.$TypeDescriptor$), .ceylon.language.Null.$TypeDescriptor$){
            
            public final .ceylon.language.Iterator<.ceylon.language.String> iterator() {
                return new .com.redhat.ceylon.compiler.java.language.AbstractIterator<.ceylon.language.String>(.com.redhat.ceylon.compiler.java.runtime.model.TypeDescriptor.union(.ceylon.language.Null.$TypeDescriptor$, .ceylon.language.String.$TypeDescriptor$)){
                    {
                        $iterator$0 = x.iterator();
                    }
                    private final .ceylon.language.Iterator<? extends .ceylon.language.String> $iterator$0;
                    private .ceylon.language.String y;
                    private boolean y$exhausted$;
                    
                    private final boolean y() {
                        final .java.lang.Object $ceylontmp$item$0 = $iterator$0.next();
                        y$exhausted$ = $ceylontmp$item$0 == .ceylon.language.finished_.get_();
                        if (y$exhausted$) {
                            return false;
                        } else {
                            y = (.ceylon.language.String)$ceylontmp$item$0;
                            return true;
                        }
                    }
                    private .java.lang.String y$2;
                    
                    private final boolean $next$1() {
                        while (true) {
                            if (!this.y()) break;
                            .ceylon.language.String y$1 = null;
                            if ((y$1 = y) != null) {
                                y$2 = y$1.toString();
                                break;
                            }
                        }
                        return !y$exhausted$;
                    }
                    
                    public final .java.lang.Object next() {
                        if (this.$next$1()) {
                            final .ceylon.language.String y = this.y;
                            final .java.lang.String y$2 = this.y$2;
                            return .ceylon.language.String.instance(y$2);
                        } else return .ceylon.language.finished_.get_();
                    }
                };
            }
        };
    }
}

src.ceylon

@noanno
{Anything*} forIf({String?*} x) {
  return { for (y in x) if (exists y) y };
}

stacktrace.md

An exception has occurred in the compiler (ceylonc 1.0.0 (No More Mr Nice Guy)). java.lang.AssertionError: Unknown symbol type tmp.package_ kind: 31 at com.sun.tools.javac.comp.Check.checkFlags(Check.java:934) at com.sun.tools.javac.comp.Enter.visitClassDef(Enter.java:402) at com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:593) at com.sun.tools.javac.comp.Enter.classEnter(Enter.java:262) at com.redhat.ceylon.compiler.java.loader.CeylonEnter.classEnter(CeylonEnter.java:279) at com.sun.tools.javac.comp.Enter.classEnter(Enter.java:276) at com.sun.tools.javac.comp.Enter.visitTopLevel(Enter.java:336) at com.sun.tools.javac.tree.JCTree$JCCompilationUnit.accept(JCTree.java:459) at com.sun.tools.javac.comp.Enter.classEnter(Enter.java:262) at com.redhat.ceylon.compiler.java.loader.CeylonEnter.classEnter(CeylonEnter.java:274) at com.sun.tools.javac.comp.Enter.classEnter(Enter.java:276) at com.sun.tools.javac.comp.Enter.complete(Enter.java:497) at com.sun.tools.javac.comp.Enter.main(Enter.java:482) at com.redhat.ceylon.compiler.java.loader.CeylonEnter.main(CeylonEnter.java:197) at com.sun.tools.javac.main.JavaCompiler.enterTrees(JavaCompiler.java:930) at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:824) at com.redhat.ceylon.compiler.java.tools.LanguageCompiler.compile(LanguageCompiler.java:223) at com.redhat.ceylon.compiler.java.launcher.Main.compile(Main.java:638) at com.redhat.ceylon.compiler.java.launcher.Main.compile(Main.java:553) at com.redhat.ceylon.compiler.java.launcher.Main.compile(Main.java:543) at com.redhat.ceylon.compiler.CeylonCompileTool.run(CeylonCompileTool.java:443) at com.redhat.ceylon.common.tools.CeylonTool.run(CeylonTool.java:343) at com.redhat.ceylon.common.tools.CeylonTool.execute(CeylonTool.java:283) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at com.redhat.ceylon.launcher.Launcher.run(Launcher.java:89) at com.redhat.ceylon.launcher.Launcher.main(Launcher.java:21) ceylon compile: Fatal error: The compiler exited abnormally (4) due to a bug in the compiler.