def __call__(self, scope, *args):
# if scope.has_key("recur") and scope["recur"] == self:
# This is recursion, don't create a new scope
# local = scope
# else:
# Calling scope -> creating scope -> local scope
# Clone creation scope so its parent can be set to calling scope
creation = Scope()
creation.bindings = self.scope.bindings
creation.parent = scope
# Create a new scope
local = Scope(creation)
# Bind `recur` to self (to alow for recursion from anonymous functions)
local["recur"] = self
# Bind each argument to a binding
bi = ai = 0
bindings = self.bindings.data[:-1]
while bi != len(bindings) and ai != len(bindings):
# Optional argument
if bindings[bi] == Symbol("?"):
if ai >= len(args):
if bindings[bi + 1].__class__ == List:
# A default value is supplied
local[bindings[bi + 1].car().data] = bindings[bi + 1].cdr().car().evaluate(local)
else:
# Nothing supplied for this optional and no default value
local[bindings[bi + 1].data] = List([])
ai -= 1
bi += 1
else:
if bindings[bi + 1].__class__ == List:
# A default value is supplied, replace with just the symbol
local[bindings[bi + 1].car().data] = args[ai].evaluate(scope)
else:
local[bindings[bi + 1].data] = args[ai].evaluate(scope)
bi += 1
# continue
# Rest argument
elif bindings[bi] == Symbol("&"):
if ai == len(args):
# raise TypeError("expected at least %d arguments, got %d" % (bi + 1, ai))
local[bindings[bi + 1].data] = List([])
else:
local[bindings[bi + 1].data] = List([x.evaluate(scope) for x in args[ai:]] + [[]])
break
# Normal argument
else:
# Too many or too few arguments
if bi >= len(bindings) or ai >= len(args):
raise TypeError("expected %d arguments, got %d" % (len(bindings), len(args)))
local[bindings[bi].data] = args[ai].evaluate(scope)
ai += 1
bi += 1
# Evaluate each expression in the body (in local function scope)
for expression in self.body[:-1]:
expression.evaluate(local)
# Return the evaluated last expression
return self.body[-1].evaluate(local)
