def Alias(newname, oldname):
"""Creates an alias for an existing element in a struct
:param newname: the new name
:param oldname: the name of an existing element
"""
return Value(newname, lambda ctx: ctx[oldname])
def If(predicate, subcon, elsevalue=None):
"""An if-then conditional construct: if the predicate indicates True,
subcon will be used; otherwise, `elsevalue` will be returned instead.
:param predicate: a function taking the context as an argument and returning True or False
:param subcon: the subcon that will be used if the predicate returns True
:param elsevalue: the value that will be used should the predicate return False.
by default this value is None.
"""
return IfThenElse(subcon.name, predicate, subcon,
Value("elsevalue", lambda ctx: elsevalue))
def Alias(newname, oldname):
"""creates an alias for an existing element in a struct
* newname - the new name
* oldname - the name of an existing element
"""
return Value(newname, lambda ctx: ctx[oldname])