jynx.lib.javaparser – Java parser for Jython

A java parser is used by Jynx. A Java parser was necessary to acquire used type declarations in Java classes and those determined single-named imports in generated Java code.

functions

parse(string) - > AST

The parse function keeps a string argument and produces an AST which corresponds to the CompilationUnit AST node.

Information extraction

Information extraction from AST nodes is visitor based. A typical visitor looks like this

@JavaClass
class TypeVisitor(VoidVisitorAdapter):
    nodes = jproperty("Vector", initializer = "new Vector()")

    @signature("public Vector _()")
    def getNodes(self):
        return self.nodes

    @Override
    @signature("public void _(ReferenceType, Object)", overload = True)
    def visit(self, n, arg):
        self.nodes.add(n)

    @Override
    @signature("public void visit(TypeParameter, Object)", overload = True)
    def visit(self, n, arg):
        self.nodes.add(n)

    ....

Notice the user of method overloading.

Known issues

I observed problems ( RuntimeError exceptions to be precise ) when calling super in a visit method

@JavaClass
class MyVisistor(VoidVisitorAdapter):

    def visit(self, n, arg):
        super(MyVisitor, self).visit(n, arg)
        ...

In some cases the problem can be removed by moving back to explicit super-class calls

@JavaClass
class MyVisistor(VoidVisitorAdapter):

    def visit(self, n, arg):
        VoidVisitorAdapter.visit(self, n, arg)
        ...

However, even this won’t prevent all recursion errors.