def first(x):
# print('x.data', x.data)
if isinstance(x, mal_types.MalNil):
return mal_types.MalNil()
elif isinstance(x, mal_types.list_types) and len(x) == 0:
return mal_types.MalNil()
return x[0]
def EVAL(ast, env):
while True:
if not isinstance(ast, mal_types.list_types):
return eval_ast(ast, env)
elif not ast:
return ast
elif isinstance(ast, mal_types.list_types):
if len(ast) == 0:
return ast
if isinstance(ast[0], mal_types.MalSymbol):
if ast[0].data == 'def!':
value = EVAL(ast[2], env)
env.set(ast[1].data, value)
return value
elif ast[0].data == 'let*':
let_env = Env(outer=env)
for k, v in zip(ast[1][::2], ast[1][1::2]):
let_env.set(k, EVAL(v, let_env))
ast, env = ast[2], let_env
continue
elif ast[0].data == 'do':
ast = eval_ast(ast[1:], env)[-1]
return ast
elif ast[0].data == 'if':
if EVAL(ast[1], env):
ast = ast[2]
continue
else:
if len(ast) == 4:
ast = ast[3]
continue
return mal_types.MalNil()
elif ast[0].data == 'fn*':
def fn(*exprs):
new_env = Env(outer=env, binds=ast[1], exprs=exprs)
return EVAL(ast[2], new_env)
return mal_types.MalFn(ast=ast[2],
params=ast[1],
env=env,
fn=fn)
# apply
evaluated_ast = eval_ast(ast, env)
if callable(evaluated_ast[0]):
f, args = evaluated_ast[0], evaluated_ast[1:]
if isinstance(f, mal_types.MalFn):
ast = f.ast
env = Env(outer=f.env, binds=f.params, exprs=args)
# print(f)
continue
else:
return f(*args)
return evaluated_ast
return mal_types.MalNil()
def read_atom(reader):
token = reader.peek()
try:
val = int(token)
return mal_types.MalNumber(val)
except ValueError:
pass
if token in _quote_mapping:
reader.next()
return mal_types.MalList(
[mal_types.MalSymbol(_quote_mapping[token]),
read_form(reader)])
elif token == '^':
reader.next()
meta_data = read_form(reader)
reader.next()
lst = read_form(reader)
return mal_types.MalList(
[mal_types.MalSymbol("with-meta"), lst, meta_data])
elif token.startswith('"') and token.endswith('"'):
return mal_types.MalString(
bytes(token[1:-1], "utf-8").decode("unicode_escape"))
elif token.startswith(":"):
return mal_types.MalKeyword(token)
elif token in ('true', 'false'):
if token == 'true':
return mal_types.MalBool(True)
return mal_types.MalBool(False)
elif token == 'nil':
return mal_types.MalNil()
return mal_types.MalSymbol(token) # symbol?
def EVAL(ast, env):
# print('EVAL', ast)
if not isinstance(ast, mal_types.list_types):
return eval_ast(ast, env)
elif not ast:
return ast
elif isinstance(ast, mal_types.list_types):
if len(ast) == 0:
return ast
if isinstance(ast[0], mal_types.MalSymbol):
if ast[0].data == 'def!':
value = EVAL(ast[2], env)
env.set(ast[1].data, value)
return value
elif ast[0].data == 'let*':
let_env = Env(outer=env)
for k, v in zip(ast[1][::2], ast[1][1::2]):
let_env.set(k, EVAL(v, let_env))
return EVAL(ast[2], let_env)
elif ast[0].data == 'do':
return eval_ast(ast[1:], env)[-1] # fixme
elif ast[0].data == 'if':
if EVAL(ast[1], env):
return EVAL(ast[2], env)
else:
if len(ast) == 4:
return EVAL(ast[3], env)
return mal_types.MalNil()
elif ast[0].data == 'fn*':
def closure(*exprs):
new_env = Env(outer=env, binds=ast[1], exprs=exprs)
# print(new_env.data)
# print(ast[2])
return EVAL(ast[2], new_env)
return closure
evaluated_ast = eval_ast(ast, env)
if callable(evaluated_ast[0]):
return evaluated_ast[0](*evaluated_ast[1:]) # apply
return evaluated_ast
return mal_types.MalNil()
def seq(x):
if not x.data:
return mal_types.MalNil()
elif isinstance(x, mal_types.MalList):
return x
elif isinstance(x, mal_types.MalVector):
return mal_types.MalList(x.data)
elif isinstance(x, mal_types.MalString):
return mal_types.MalList([mal_types.MalString(i) for i in x.data])
def prn(*args):
print(" ".join([pr_str(i, print_readably=True) for i in args]))
return mal_types.MalNil()
def meta(x):
return getattr(x, 'metadata', mal_types.MalNil())
def readline(string):
try:
return mal_types.MalString(input(string))
except EOFError:
return mal_types.MalNil()
def get(x, key):
if isinstance(x, mal_types.MalHashMap):
return x.get(key)
return mal_types.MalNil()
def EVAL(ast, env):
while True:
# print('INLOOP', ast)
if not isinstance(ast, mal_types.list_types):
return eval_ast(ast, env)
elif not ast:
return ast
elif isinstance(ast, mal_types.list_types):
if len(ast) == 0:
return ast
ast = macroexpand(ast, env)
if not isinstance(ast, mal_types.list_types):
return eval_ast(ast, env)
if isinstance(ast[0], mal_types.MalSymbol):
if ast[0].data == 'macroexpand':
return macroexpand(ast[1], env)
if ast[0].data == 'def!':
value = EVAL(ast[2], env)
env.set(ast[1].data, value)
return value
elif ast[0].data == 'defmacro!':
value = EVAL(ast[2], env)
value.is_macro = True
env.set(ast[1].data, value)
return value
elif ast[0].data == 'let*':
let_env = Env(outer=env)
for k, v in zip(ast[1][::2], ast[1][1::2]):
new_value = EVAL(v, let_env)
let_env.set(k, new_value)
# print('let_env', k, new_value)
ast, env = ast[2], let_env
continue
elif ast[0].data == 'do':
return eval_ast(ast[1:], env)[-1]
elif ast[0].data == 'if':
if EVAL(ast[1], env):
ast = ast[2]
continue
else:
if len(ast) == 4:
ast = ast[3]
continue
return mal_types.MalNil()
elif ast[0].data == 'fn*':
def fn(*exprs):
new_env = Env(outer=env, binds=ast[1], exprs=exprs)
return EVAL(ast[2], new_env)
return mal_types.MalFn(ast=ast[2],
params=ast[1],
env=env,
fn=fn)
elif ast[0].data == 'quote':
return ast[1]
elif ast[0].data == 'quasiquote':
ast = quasiquote(ast[1])
continue
elif ast[0].data == 'try*':
try:
return EVAL(ast[1], env)
except mal_types.MalException as e:
new_env = Env(outer=env)
new_env.set(ast[2][1], e)
return EVAL(ast[2][2], new_env)
# apply
evaluated_ast = eval_ast(ast, env)
if callable(evaluated_ast[0]):
#print("function", ast)
f, args = evaluated_ast[0], evaluated_ast[1:]
# print('f', f)
# print('args', args)
if isinstance(f, mal_types.MalFn):
ast = f.ast
env = Env(outer=f.env, binds=f.params, exprs=args)
continue
else:
# print('********************f', f)
# print('********************args', args)
# print('@result', type(x), x)
return f(*args)
return evaluated_ast
return mal_types.MalNil()
