def check_connect(self, src, dest, scope):
"""Check validity of connecting a source expression to a destination
expression, and determine if we need to create links to pseudocomps.
"""
if self.get_source(dest) is not None:
scope.raise_exception(
"'%s' is already connected to source '%s'" %
(dest, self.get_source(dest)), RuntimeError)
destexpr = ConnectedExprEvaluator(dest, scope, is_dest=True)
srcexpr = ConnectedExprEvaluator(src, scope, getter='get_attr_w_copy')
srccomps = srcexpr.get_referenced_compnames()
destcomps = list(destexpr.get_referenced_compnames())
if destcomps and destcomps[0] in srccomps:
raise RuntimeError("'%s' and '%s' refer to the same component." %
(src, dest))
try:
return srcexpr, destexpr, self._needs_pseudo(srcexpr, destexpr)
except AttributeError as err:
exc_type, value, traceback = sys.exc_info()
invalid_vars = srcexpr.get_unresolved() + destexpr.get_unresolved()
parts = invalid_vars[0].rsplit('.', 1)
parent = repr(scope.name) if scope.name else 'top level assembly'
vname = repr(parts[0])
if len(parts) > 1:
parent = repr(parts[0])
vname = repr(parts[1])
msg = "{parent} has no variable {vname}"
msg = msg.format(parent=parent, vname=vname)
raise AttributeError, AttributeError(msg), traceback
