I can easily understand #members. It add members to the parser class. But what does scope mean?
scope Symbols{
Set types;
}
Is "Symbols" a member in parser class? I check the generated java file,
protected static class Symbols_scope {
Set types;
}
protected Stack Symbols_stack = new Stack();
The scope becomes an inner class and a Stack member.
And When I use Symbols::types in rule action, I see this in java file,
Symbols_stack.push(new Symbols_scope());
int translation_unit_StartIndex = input.index();
((Symbols_scope)Symbols_stack.peek()).types = new HashSet();
So, every time I refer to "symbol", it create a new instance of "Symbol" and push it into the stack?
And there are global and local scopes. What is the difference? In the java file they both generate an inner class and a Stack member. Then what make "global scope" global and make "local scope" local?
Related
I have a scripting system where depending on where the script is executed you have access to different variables. I also want to have inferred types for a type of Auto-Completion for the script editor.
But when the types are inferred during the compile phase, I have no way of giving a Binding which explains to the compilation phase what types those dynamic variables have.
I have currently solved this by:
Not compiling the code with either #TypeChecked nor #CompileStatic but later manually running a subclassed StaticCompilationVisitor on the dynamically typed codebase and manually filling in the StaticTypesMarker.INFERRED_TYPE inside visitVariableExpression() for the dynamic variables that I know exists.
However, this seems like the wrong way to go about it, and I would actually like to work with the VariableScope instead. But it seems to be under rough lockdown inside the VariableScopeVisitor, so it's difficult to pop in a CustomVariableScope that dynamically does the lookups. I have managed to do this with reflection, replacing the VariableScopeVisitor inside CompilationUnit and currentScope and such inside VaribleScopeVisitor. It works, but I don't like working against hard-coded private field names.
This might be a long-winded way of asking: Is there an official way of handling a situation of static typing with dynamic variables? I cannot do this by setting scriptBaseClass for reasons too complex to explain here.
If the question is unclear, please tell me and I'll try to edit in better explanations.
The answer was to add a GroovyTypeCheckingExtensionSupport to a StaticTypeCheckingVisitor and then use visitClass on the first ClassNode of the CompilationUnit.
final ClassNode classNode = this.compilationUnit.getFirstClassNode();
final StaticCompilationVisitor visitor = new StaticCompilationVisitor(this.sourceUnit, classNode);
visitor.addTypeCheckingExtension(new MyGroovyTypeCheckingExtensionSupport(visitor, this.compilationUnit));
visitor.visitClass(classNode);
visitor.performSecondPass();
And create something like the class below:
private static class MyGroovyTypeCheckingExtensionSupport extends GroovyTypeCheckingExtensionSupport {
private static final ClassNode CLASSNODE_OBJECT = ClassHelper.make(Object.class);
public MyGroovyTypeCheckingExtensionSupport(StaticTypeCheckingVisitor typeCheckingVisitor, CompilationUnit compilationUnit) {
super(typeCheckingVisitor, "", compilationUnit);
}
#Override
public boolean handleUnresolvedVariableExpression(VariableExpression vexp) {
final ClassNode type = this.getType(vexp);
if (type == null || type.equals(CLASSNODE_OBJECT)) {
if (vextp.getName().equals("something")) {
this.storeType(vexp, ClassHelper.make(SomeClass.class));
return true;
}
}
return false;
}
}
I have a functioning WCMUsePojo Groovy class which is called from a sightly html component. I am trying to create an instance of my WCMUsePojo class for testing based on the content from the Prosper setup method.
It's basically the same type of question as How can I create an instance of WCMUsePojo in a servlet for a specific page? But I don't see it answered and this is specifically about how to unit test methods in WCMUsePojo classes within the Prosper framework. Is there a Java or Groovy equivalent to Sightly's data-sly-use attribute?
def setupSpec() {
pageBuilder.content {
page_with_new_gridwrapper {
'jcr:content'{
'gridpar' {
'my_gridwrapper'('sling:resourceType':'my/components/my_gridwrapper') {
}
}
}
}
}
}
def "Test Page with New Grid Container"(){
Page page = pageManager.getPage("/content/page_with_new_gridwrapper")
// the following 2 lines return null :-(
// but I would prefer these to return an object with the type MyGridContainerHelper
MyGridContainerHelper cmp = page.getContentResource().getChild("gridpar/my_gridwrapper").adaptTo(MyGridContainerHelper.class)
Component cmp2 = WCMUtils.getComponent(page.getContentResource().getChild("gridpar/my_gridwrapper"))
expect:
page != null //passes
page.getContentResource().getChild("gridpar/my_gridwrapper") != null //passes
cmp != null // fails
cmp2 != null // fails
cmp.resourceType == "my/components/my_gridwrapper" // fails
}
To adapt an instance of MyGridContainerHelper from a resource object, you can implement your helper class using Sling Models rather than extending WCMUsePojo. Prosper supports registration of #org.apache.sling.models.annotations.Model-annotated classes by using the following syntax in the setupSpec block of your specification:
slingContext.addModelsForPackage("helper.class.package.name")
This eliminates the need to manually construct a Bindings object and initialize the POJO; the Sling model factory does all the work for you. Since Sightly's "use" attribute supports any class that is adaptable from a Resource or SlingHttpServletRequest, no additional changes are required for your existing Sightly template.
I ended up instantiating the object and calling the init method passing in a SimpleBindings object containing the resource I was testing with. This seems to work well for my purposes.
MyGridContainerHelper gridContainer = new MyGridContainerHelper();
SimpleBindings bindings = new SimpleBindings()
bindings.put("resource", page.getContentResource().getChild("gridpar/my_gridwrapper"))
gridContainer.init(bindings)
i want to parse a project in which some classes have inner classes.how can i extract inner classes name other information using eclips JDT?
You can traverse through the Compilation unit of the Java class and visit the TypeDeclaration AST node. The below code can then be used to check if it is not a top-level class, i.e an inner class.
public boolean visit(TypeDeclaration typeDeclarationStatement) {
if (!typeDeclarationStatement.isPackageMemberTypeDeclaration()) {
System.out.println(typeDeclarationStatement.getName());
// Get more details from the type declaration.
}
return true;
}
For getting anonymous inner classes use the below code too:
public boolean visit(AnonymousClassDeclaration anonyomousClassDeclaration) {
System.out.println(anonyomousClassDeclaration.toString());
return true;
}
Details on Class traversal using JDT can be found from below link:
Eclipse create CompilationUnit from .java file
If you have an IType instance (type) then you can query the inner classes by
type.getTypes();
which will give you an array of the immediate member types declared by this type.
i have a structure defined, which contains a public field and a public property named _one and One respectively, now i instantiate the struct in the main function (not creating new object), and called the Property from the struct, i am getting the compile time error saying use of unassigned local variable One, however when i called the field _one, it works pretty expected here what i am doing:
public struct myStruct
{
public int _one;
public int One
{
get { return _one; }
set { _one = value; }
}
public void Display()
{
Console.WriteLine(One);
}
}
static void Main(string[] args)
{
myStruct _struct;
_struct.One = 2; // Does not works
_struct._one = 2; // Works fine
}
can anyone explain whats the reason behind this, could not understand the concept.
You need to initialize the struct in order for the property to be accessible - _struct has a default value otherwise:
myStruct _struct = new myStruct();
By the way - mutable value types are evil.
This is unintuitive behavior, but it is permitted by the rules of Definite assignment checking. Described in excruciating detail in section 5.3 of the C# Language Specification. The key phrase, early in the chapter is:
In additional to the rules above, the following rules apply to struct-type variables and their instance variables:
- An instance variable is considered definitely assigned if its containing struct-type variable is considered definitely assigned.
- A struct-type variable is considered definitely assigned if each of its instance variables is considered definitely assigned.
It is the latter rule that permits this. In other words, you can also initialize a struct by assigning all of its variables. You can see this by trying these snippets:
myStruct _struct = new myStruct();
_struct.Display(); // fine by the 1st bullet
myStruct _struct;
_struct.Display(); // bad
myStruct _struct;
_struct._one = 2;
_struct.Display(); // fine by the 2nd bullet
So you don't get CS0165 by assigning the field because that would disallow initializing the structure by assigning its variables.
The reasons which would favor using read-write properties instead of exposed fields in class definitions do not apply to structures, since they can support neither inheritance nor update notifications, and the mutability of a struct's field depends upon the mutability of the struct instance, regardless of whether the field is exposed or not. If a struct is supposed to represent a group of related but freely-independently-modifiable variables, it should simply expose those variables as fields. If a property with a backing field is supposed to be read-only, the constructor should set the backing field directly, rather than via property setter.
UPDATE
I have to apologize for confusing the readers. After I got totally lost in the code, I reverted all my changes from Mercurial repo, carefully applied the same logic as before -- and it worked. The answers below helped me understand the (new to me) concept better, and for that I gave them upvotes.
Bottom line: if a call to a missing method happens within a closure, and resolution set to DELEGATE_FIRST, methodMissing() will be called on the delegate. If it doesn't -- check you own code, there is a typo somewhere.
Thanks a lot!
Edit:
OK, now that you've clarified what your are doing (somewhat ;--))
Another approach (one that I use for DSLs) is to parse your closure group to map via a ClosureToMap utility like this:
// converts given closure to map method => value pairs (1-d, if you need nested, ask)
class ClosureToMap {
Map map = [:]
ClosureToMap(Closure c) {
c.delegate = this
c.resolveStrategy = Closure.DELEGATE_FIRST
c.each{"$it"()}
}
def methodMissing(String name, args) {
if(!args.size()) return
map[name] = args[0]
}
def propertyMissing(String name) { name }
}
// Pass your closure to the utility and access the generated map
Map map = new ClosureToMap(your-closure-here)?.map
Now you can iterate through the map, perhaps adding methods to applicable MCL instance. For example, some of my domains have dynamic finders like:
def finders = {
userStatusPaid = { Boolean active = true->
eq {
active "$active"
paid true
}
}
}
I create a map using the ClosureToMap utility, and then iterate through, adding map keys (methods, like "userStatus") and values (in this case, closure "eq") to domain instance MCL, delegating the closure to our ORM, like so:
def injectFinders(Object instance) {
if(instance.hasProperty('finders')) {
Map m = ClosureToMap.new(instance.finders).map
m?.each{ String method, Closure cl->
cl.delegate = instance.orm
cl.resolveStrategy = Closure.DELEGATE_FIRST
instance.orm.metaClass."$method" = cl
}
}
}
In this way in controller scope I can do, say:
def actives = Orders.userStatusPaid()
and "eq" closure will delegate to the ORM and not domain Orders where an MME would occur.
Play around with it, hopefully I've given you some ideas for how to solve the problem. In Groovy, if you can't do it one way, try another ;--)
Good luck!
Original:
Your missingMethod is defined on string metaclass; in order for it to be invoked, you need "someString".foo()
If you simply call foo() by itself within your closure it will fail, regardless of delegation strategy used; i.e. if you don't use the (String) delegate, good luck. Case in point, do "".foo() and it works.
I don't fully understand the issue either, why will you not have access to the closure's delegate? You are setting the closure's delegate and will invoke the closure, which means you will have access to the delegate within the closure itself (and can just delegate.foo())
nope, you will not catch a missing method and redirect it to the delegate with metaclass magic.
the closure delegate is the chance to capture those calls and adapt them to the backing domain.
that means...
you should create your own delegate with the methods required by the dsl.
do not try to force a class to do delegate work if it's not designed for the task, or the code will get really messy in not time.
keep everything dsl related in a set of specially designed delegate classes and everything will suddenly become ridiculously simple and clear.