def read_atom(readerInst):
""" this function will look at the contents of the token and return the appropriate scalar (simple/single) data type value. Initially, you can just implement numbers(integers) and symbols. This will allow you to proceed through the next couple of steps before you will need to implement the other fundamental MAL types: nil, true, false, and string. The remaining MAL types: keyword, vector, hash-map, and atom do not need to be implemented until step 9 (but can be implemented at any point between this step and that). BTW, symbol types are just objects that contain a single string name value."""
if not readerInst.has_token():
raise SyntaxError('reached EOF')
malItem = readerInst.next()
try:
intNum = int(malItem)
return parser.IntSymbol(intNum)
except ValueError:
#print ("malItem:", malItem)
#print ("len:", len(malItem))
if ((len(malItem) > 1) and (malItem[0] == '"')
and (malItem[-1] == '"')):
s = printer.unescape(malItem[1:-1])
#print ("making lisp string:", s)
#for i,c in enumerate(s):
# print (i, c)
return parser.LispString(s)
if ((len(malItem) > 1) and (malItem[0] == ':')):
s = malItem[1:]
return parser.LispKeyword(s)
if malItem == 'nil':
return parser.NilSymbol()
elif malItem == 'true':
return parser.TrueSymbol()
elif malItem == 'false':
return parser.FalseSymbol()
else:
return parser.StrSymbol(malItem)
def func_seq(arg):
if (isinstance(arg, parser.NilSymbol)):
return parser.NilSymbol()
if (isinstance(arg, parser.LispList)
or isinstance(arg, parser.LispVector)):
if len(arg.values) == 0:
return parser.NilSymbol()
return parser.LispList(arg.values)
if isinstance(arg, parser.LispString):
if len(arg.str) == 0:
return parser.NilSymbol()
return parser.LispList([parser.LispString(x) for x in list(arg.str)])
def func_readline(arg):
prompt = printer.pr_str(arg, False)
try:
if sys.version_info[0] >= 3:
#print(prompt, end='', flush=True)
in_str = input(prompt)
else:
in_str = raw_input(prompt)
return parser.LispString(in_str)
except EOFError:
return parser.NilSymbol()
def EVAL(ast, env):
while True:
#print ("evaluating", ast)
if not isinstance(ast, parser.LispList):
return eval_ast(ast, env)
if len(ast.values) == 0:
return ast
ast = macro_expand(ast, env)
if not isinstance(ast, parser.LispList):
return eval_ast(ast, env)
op = ast.values[0]
#print ("op", op)
if isinstance(op, parser.StrSymbol) and op.val == 'def!':
"""call the set method of the current environment (second parameter of
EVAL called env) using the unevaluated first parameter (second
list element) as the symbol key and the evaluated second
parameter as the value."""
val = EVAL(ast.values[2], env)
env.set(ast.values[1].val, val)
return val
if isinstance(op, parser.StrSymbol) and op.val == 'defmacro!':
val = EVAL(ast.values[2], env)
val.setMacro(True)
env.set(ast.values[1].val, val)
return val
elif isinstance(op, parser.StrSymbol) and op.val == 'let*':
newenv = environment.Environment(env, [], [])
for i in range(0, len(ast.values[1].values), 2):
name = ast.values[1].values[i].val
val = EVAL(ast.values[1].values[i+1], newenv)
newenv.set(name, val)
env = newenv
ast = ast.values[2]
continue
elif isinstance(op, parser.StrSymbol) and op.val == 'do':
ret = None
for t in ast.values[1:-1]:
#print ("evaluating",t)
ret = EVAL(t, env)
#print ("got ret")
#print ("env:", env)
ast = ast.values[-1]
continue
elif isinstance(op, parser.StrSymbol) and op.val == 'if':
#print ("evaluating if")
test = EVAL(ast.values[1], env)
#print ("test:", test)
if not (isinstance(test, parser.NilSymbol) or isinstance(test, parser.FalseSymbol)):
# true eval
#print ("test was true, evaluating", ast.values[2])
ast = ast.values[2]
continue
elif len(ast.values) > 3:
#print ("test was false, evaluating else", ast.values[3])
#else
ast = ast.values[3]
continue
else:
#print ("test was false, returning Nil")
return parser.NilSymbol()
elif isinstance(op, parser.StrSymbol) and op.val == 'fn*':
newenv = environment.Environment(env, [], [])
params = [x.val for x in ast.values[1].values]
body = ast.values[2]
#print ("making func", params, body)
funcClosure = parser.FuncClosure(newenv, params, body, EVAL)
return funcClosure
elif isinstance(op, parser.StrSymbol) and op.val == 'quote':
return ast.values[1]
elif isinstance(op, parser.StrSymbol) and op.val == 'quasiquote':
ast = quasiquote(ast.values[1])
continue
elif isinstance(op, parser.StrSymbol) and op.val == 'macroexpand':
return macro_expand(ast.values[1], env)
elif isinstance(op, parser.StrSymbol) and op.val == 'try*':
catchop = ast.values[2].values[0]
if isinstance(catchop, parser.StrSymbol) and catchop.val == 'catch*':
try:
return EVAL(ast.values[1], env)
except parser.MalException as me:
ex_label = ast.values[2].values[1].val
newenv = environment.Environment(env, [ex_label], [me.mal_obj])
return EVAL(ast.values[2].values[2], newenv)
except Exception as e:
ex_label = ast.values[2].values[1].val
ex_str = parser.LispString(str(e))
newenv = environment.Environment(env, [ex_label], [ex_str])
return EVAL(ast.values[2].values[2], newenv)
else:
return EVAL(ast.values[1], env)
else:
ast_list = eval_ast(ast, env)
if isinstance(ast_list.values[0], parser.FuncClosure):
func = ast_list.values[0]
ast = func.body
env = func.prepareEnv(ast_list.values[1:])
continue
#print ("about to call", ast_list.values[0])
return ast_list.values[0](*ast_list.values[1:])
def mainloop():
while True:
s = input("user> ")
try:
print (rep(s))
except ValueError as e:
print(e)
except IndexError as e:
print(e)
except parser.MalException as me:
print(me)
print(printer.pr_str(me.mal_obj, True))
if __name__ == "__main__":
if len(sys.argv) == 1:
mainloop()
else:
#print ("processing command line:", sys.argv)
fn = sys.argv[1]
#print ("processing file:", fn)
#print ("extra args:", sys.argv[2:])
argStrings = [parser.LispString(x) for x in sys.argv[2:]]
listObj = parser.LispList(argStrings)
repl_env.set('*ARGV*', listObj)
rep('(load-file "{0}")'.format(fn))
#print("Done")
def func_python_eval(arg):
s = printer.pr_str(arg, False)
val = str(eval(s))
return parser.LispString(val)
def func_slurp(arg):
if not isinstance(arg, parser.LispString):
raise ArgumentError("should be a string")
fn = arg.str
with open(fn) as fileObj:
return parser.LispString(fileObj.read())
def func_str(*args):
strings = [printer.pr_str(a, False) for a in args]
joined = "".join(strings)
return parser.LispString(joined)