def read_atom(reader):
token = reader.next()
if token == 'nil':
return NIL
elif token == 'true':
return TRUE
elif token == 'false':
return FALSE
elif re.match(r'-?\d+\.*\d*', token):
return make_number(token)
elif token.startswith('"'):
if not valid_string(token):
raise MalException('EOF')
return make_string(token)
elif token.startswith(':'):
return make_keyword(token)
elif re.match(r'.*', token):
return make_symbol(token)
raise MalException('Input/output error')
def read_list(tokens: Reader):
map = {"(": ")", "{": "}", "[": "]"}
out = list()
tokens.next()
while (tokens.peek() != ")" and tokens.peek() is not None):
out.append(read_form(tokens))
tokens.next()
if tokens.peek() is None:
raise MalException("missing closing )")
return out
def eval_ast(ast, env):
if isinstance(ast, Symbol):
out = env.get(str(ast))
if out is None:
raise MalException("symbol not found")
else:
return out
if isinstance(ast, list):
if len(ast) == 0:
return []
else:
out = list()
for x in ast:
out.append(EVAL(x, env))
return out
return ast
def read_atom(tokens: Reader):
token = tokens.peek()
int_re = re.compile(r"-?[0-9]+$")
float_re = re.compile(r"-?[0-9][0-9.]*$")
if token[0] == "\"":
if token[-1] == "\"":
return String(token[1:-1])
else:
raise MalException("missing closing \"")
if re.match(int_re, token): return Integer(int(token))
if re.match(float_re, token): return float(token)
if token == "true": return Bolean(True)
if token == "false": return Bolean(False)
if token == "nill": return Nill()
return Symbol(token)
def _check_position(self):
if self._position >= len(self._tokens):
raise MalException('EOF')
def throw(obj): raise MalException(obj) # String functions def pr_str(*args):
def _throw(val):
raise MalException(val)
def throw(exc):
raise MalException(exc)
def throw(exception: MalExpression) -> MalExpression:
raise MalException(exception)
def nth(a, b):
try:
return a[b]
except IndexError:
raise MalException("range")
def throw(x):
raise MalException(x)
def throw(obj):
raise MalException(obj)
def find(self, key):
if key in self.data:
return self
if self.outer is not None:
return self.outer.find(key)
raise MalException(MalString("'{}' not found".format(key)))
