def apply(self, args, call_env):
if len(args) != 1:
raise Exception("Arity error")
tgt = args[0].evaluate(call_env)
if not isinstance(tgt, types.List):
raise SyntaxError("rest only accepts a list")
return types.List(*tgt.elements[1:])
def apply(self, args, call_env):
if len(args) != 2:
raise Exception("Arity error")
elem = args[0].evaluate(call_env)
tgt = args[1].evaluate(call_env)
if not isinstance(tgt, types.List):
raise SyntaxError("the second argument of cons must be a list")
return types.List(elem, *tgt.elements)
def backquote_evaluate(self, expr, env):
if isinstance(expr, types.List):
if len(expr) > 0:
if (isinstance(expr.elements[0], types.Symbol) and
isinstance(env.get_form(expr.elements[0]), UnQuoteForm)):
return expr.evaluate(env)
ret = []
for e in expr.elements:
ret.append(self.backquote_evaluate(e, env))
return types.List(*ret)
return expr
def parse_list(self, token):
lst = []
next_token = self.get_token()
if next_token is None:
raise self.ParseError("Expected end of list before end of input")
while next_token.type != PLispTokens.END_EXPR:
lst.append(self.parse_expression(next_token))
next_token = self.get_token()
if next_token is None:
raise self.ParseError(
"Expected end of list before end of input")
return types.List(*lst)
def apply(self, args, call_env):
res = types.List()
for expr in args:
res = expr.evaluate(call_env)
return res
def apply(self, args, call_env):
if len(args) == 0:
return types.List()
return self.backquote_evaluate(args[0], call_env)
def apply(self, args, call_env):
if len(args) == 0:
return types.List()
return args[0].evaluate(call_env)
def apply(self, args, call_env):
string = ' '.join([str(a.evaluate(call_env)) for a in args])
print(string)
return types.List()
def apply(self, args, call_env):
return types.List(*[e.evaluate(call_env) for e in args])
def parse_unquote(self, token):
body = self.parse_expression(self.get_token())
if body is None:
raise self.ParseError("Invalid body for unquote")
return types.List(types.Symbol("unquote"), body)