def load(filename):
print "Loading and executing %s" % filename
rps = 0
full_line = ""
line_num = 1
for line in open(filename, "r"):
line = line.strip()
full_line += line
rps += line.count("(")-line.count(")")
if rps == 0 and full_line.strip() != "":
try:
tokens = tokenize(full_line)
while len(tokens) > 0:
val = eval(parse(tokens),global_env)
except SystemExit:
exit()
except:
print "\nAn error occurred on line %d:\n\t%s\n" % (line_num,full_line)
traceback.print_exc()
break
full_line = ""
line_num += 1
def repl(prompt='vernal> '):
try:
while True:
full_line = raw_input(prompt)
rps = full_line.count("(")-full_line.count(")")
while rps != 0 or full_line == "":
line = raw_input(">\t")
full_line += line
rps += line.count("(")-line.count(")")
try:
tokens = tokenize(full_line)
while len(tokens) > 0:
val = eval(parse(tokens),global_env)
if val is not None: print to_string(val)
except ValueError as e:
print e.message
except Exception as e:
raise e
except (KeyboardInterrupt, SystemExit):
pass
except:
print "\nFatal Error\n"
traceback.print_exc()
def begin(v,*x): val = 0 for e in x[:-1]: val = eval(e, v) return Tail(x[-1], v)
def vprint(v,e): val = eval(e, v) print to_string(val) return val
def cond(v,*x):
for (p, e) in x:
if eval(p, v):
return Tail(e, v)
raise ValueError("No Branch Evaluates to True")
def setvar(v,var,e): val = eval(e, v) env.find(var)[var] = val return val
def defvar(v,var,e): val = eval(e, v) v[var] = val return val
def closure(call_env, *args): new_env = Env(zip(vars,[eval(exp, call_env) for exp in args]), clos_env) new_env['%'] = call_env return Tail(body, new_env)
return Tail(e, v)
raise ValueError("No Branch Evaluates to True")
def begin(v,*x):
val = 0
for e in x[:-1]:
val = eval(e, v)
return Tail(x[-1], v)
def vprint(v,e):
val = eval(e, v)
print to_string(val)
return val
global_env = Env({
'+': lambda v,x,y:eval(x,v)+eval(y,v),
'-': lambda v,x,y:eval(x,v)-eval(y,v),
'*': lambda v,x,y:eval(x,v)*eval(y,v),
'/': lambda v,x,y:eval(x,v)/eval(y,v),
'>': lambda v,x,y:eval(x,v)>eval(y,v),
'<': lambda v,x,y:eval(x,v)<eval(y,v),
'>=': lambda v,x,y:eval(x,v)>=eval(y,v),
'<=': lambda v,x,y:eval(x,v)<=eval(y,v),
'=': lambda v,x,y:eval(x,v)==eval(y,v),
'eq?': lambda v,x,y:
(lambda vx,vy: (not isa(vx, list)) and (vx == vy))(eval(x,v),eval(y,v)),
'cons': lambda v,x,y:[eval(x,v)]+eval(y,v),
'car': lambda v,x:eval(x,v)[0],
'cdr': lambda v,x:eval(x,v)[1:],
'list': lambda v,*x:[eval(expr, v) for exp in x],
'append': lambda v,x,y:eval(x,v)+eval(y,v),
