def def_(args, scopes):
if len(args) != 2:
raise TypeError("def takes two arguments")
atom = args.first()
rhs = args.second()
if type(atom) is not Atom:
raise TypeError("First argument to def must be atom")
scopes[-1][atom.name()] = evaluate(rhs, scopes)
def evaluate(x, scopes):
if type(x) in (int, float):
return x
elif type(x) is Atom:
val = find_in_scopechain(scopes, x.name())
if not val:
raise UnknownVariable("Unknown variable: %s" % x.name())
else:
return val
elif type(x) is Keyword:
return x
elif type(x) is Vector:
return apply(Vector, [evaluate(el, scopes) for el in x])
elif type(x) is Map:
return Map(dict([(evaluate(k, scopes), evaluate(v, scopes))
for k, v in x.items()]))
elif type(x) is List:
contents = x
return eval_list(contents, scopes)
return x
def eval_list(contents, scopes):
if contents.empty():
return List() # ()
first = contents.first()
rest = contents.rest()
if type(first) is Map:
if not rest.rest().empty():
raise TypeError("Map lookup takes one argument")
return evaluate(first, scopes)[evaluate(rest.first(), scopes)]
elif type(first) is Atom:
name = first.name()
if name in BUILTIN_FUNCTIONS:
func = BUILTIN_FUNCTIONS[name]
return func(rest, scopes)
else:
val = find_in_scopechain(scopes, name)
if not val:
raise UnknownVariable("Function %s is unknown" % name)
if callable(val):
args = map((lambda obj: evaluate(obj, scopes)), rest)
return val(*args)
else:
raise TypeError("%s is not callable" % name)
def main():
global_scope = GlobalScope()
scopechain = [global_scope]
while True:
try:
txt = raw_input("pyclojure> ")
if re.search('^\s*$', txt):
continue
else:
print(tostring(evaluate(
parser.parse(txt, lexer=lexer), scopechain)))
except EOFError:
break
except KeyboardInterrupt:
print # Give user a newline after Cntrl-C for readability
break
except Exception, e:
print e
def evalparse(x):
return evaluate(parse(x), scopechain)
def evalparse(x):
return evaluate(parse(x), scopechain)
