# Copyright 2006-2007 Kevin Reid, under the terms of the MIT X license
# found at http://www.opensource.org/licenses/mit-license.html ................

pragma.syntax("0.9")

def EventuallyDeepFrozen :(<import:org.erights.e.elib.slot.Same>)[DeepFrozen."eventually"()] := DeepFrozen."eventually"()

def root implements DeepFrozen, ExitViaHere {
 /** Produces an object to serve as the root of 'extends' chains. It responds 'no such method' to everything, but refers to 'self' in the error instead of the  parent-most object. */
 to get(self) {
  return def root1 implements EventuallyDeepFrozen {

    method __optSealedDispatch(brand) :any {
      if (brand == EventuallyDeepFrozen.getPeekBrand()) {
        EventuallyDeepFrozen.getPeekSealer().seal(meta.getState())
      }
    }
    
    to __printOn(out :TextWriter) {
      out.write("<delegation root for ")
      out.quote(self)
      out.write(">")
    }
    
    match [=="__getAllegedType", []] {
      # Miranda __getAllegedType/0 invokes matchers
      null.__getAllegedType()
    }
    
    # match [=="__respondsTo", [verb, arity]] { # XXX not proven necessary yet
    
    match [verb, args] {
      # XXX typed exception
      # XXX have built-in no-such-method give this more useful error
      throw(`the ${self.__getAllegedType().getFQName()} ${E.toQuote(self)} does not understand $verb/${args.size()} $args`)
    }
  } 
}}