def slurp(*args: t.MalType) -> t.MalType:
if len(args) != 1 or not isinstance(args[0], t.MalString):
raise MalError('Expected slurp arg to be string')
try:
with open(args[0].value, 'r') as f:
return t.MalString(f.read())
except FileNotFoundError:
raise MalError(f'File {args[0].value} does not exist')
except OSError:
raise MalError(f'Failed to read file {args[0].value}')
def wrapper(*args: t.MalType) -> t.MalType:
if not all(isinstance(i, t.MalInt) for i in args):
raise MalError('Only ints are supported as arguments')
acc, *rest = map(o.attrgetter('value'),
args) # type: Tuple[int, List[int]]
for i in rest:
acc = op(acc, i)
return t.MalInt(acc)
def swap(*args: t.MalType) -> t.MalType:
if (len(args) < 2 or not isinstance(args[0], t.MalAtom)
or not isinstance(args[1], t.MalCallable)):
raise MalError('Expected atom and function as arguments to swap!')
atom, callable_, *rest = args
assert isinstance(atom, t.MalAtom) and isinstance(callable_, t.MalCallable)
if isinstance(callable_, t.MalTCOFunction):
callable_ = callable_.fn
assert isinstance(callable_, t.MalFunction), 'Unsupported callable'
new_value = atom.inner = callable_.fn(atom.inner, *rest)
return new_value
def EVAL(in_: t.MalType, env: Env) -> t.MalType:
if not isinstance(in_, t.MalList):
return eval_ast(in_, env)
if not in_.items:
return in_
f, *args = in_.items
if isinstance(f, t.MalSymbol):
if f.name == 'def!':
if len(args) != 2:
raise MalError('Expected 2 arguments to "def!"')
dest, val = args
if not isinstance(dest, t.MalSymbol):
raise MalError('Expected symbol name to "def!"')
res = env[dest.name] = EVAL(val, env)
return res
elif f.name == 'let*':
if len(args) != 2:
raise MalError('Expected 2 arguments to "let*"')
new_env = env.new_child()
bindings, body = args
if (not isinstance(bindings, (t.MalVector, t.MalList))
or len(bindings.items) % 2 != 0):
raise MalError('Expected let* bindings to be even length list')
for i in range(0, len(bindings.items) // 2 + 1, 2):
name, value = bindings.items[i:i + 2]
if not isinstance(name, t.MalSymbol):
raise MalError('Expected symbol name in let* binding')
new_env[name.name] = EVAL(value, new_env)
return EVAL(body, new_env)
f, *args = cast(t.MalList, eval_ast(in_, env)).items
if isinstance(f, t.MalFunction):
return f.fn(*args)
raise MalError(f'Value {pr_str(f)} is not callable')
def eval_ast(ast: t.MalType, env: Env):
if isinstance(ast, t.MalSymbol):
if ast.name in env:
return env[ast.name]
raise MalError(f'Unbound symbol {ast.name}')
if isinstance(ast, (t.MalList, t.MalVector)):
return type(ast)([EVAL(i, env) for i in ast.items])
if isinstance(ast, t.MalHashMap):
items = []
for k, v in ast.items.items():
items.append(k)
items.append(EVAL(v, env))
return t.MalHashMap(items)
return ast
def eval_ast(ast: t.MalType, env: Env) -> t.MalType:
if isinstance(ast, t.MalSymbol):
try:
return env[ast.name]
except KeyError:
raise MalError(f'{ast.name} not found')
if isinstance(ast, (t.MalList, t.MalVector)):
return type(ast)([EVAL(i, env) for i in ast.items])
if isinstance(ast, t.MalHashMap):
items = []
for k, v in ast.items.items():
items.append(k)
items.append(EVAL(v, env))
return t.MalHashMap(items)
return ast
def list_p(*args: t.MalType) -> t.MalType:
if len(args) != 1:
raise MalError(f'Expected 1 argument to list?, got {len(args)}')
return t.MalBool(isinstance(args[0], t.MalList))
def atom_p(*args: t.MalType) -> t.MalType:
if len(args) != 1:
raise MalError('Expected one argument to atom?')
return t.MalBool(isinstance(args[0], t.MalAtom))
def EVAL(in_: t.MalType, env: Env) -> t.MalType:
while True:
if not isinstance(in_, t.MalList):
return eval_ast(in_, env)
if not in_.items:
return in_
f, *args = in_.items
if isinstance(f, t.MalSymbol):
if f.name == 'def!':
if len(args) != 2:
raise MalError('Expected 2 arguments to "def!"')
dest, val = args
if not isinstance(dest, t.MalSymbol):
raise MalError('Expected symbol name to "def!"')
res = env[dest.name] = EVAL(val, env)
return res
if f.name == 'let*':
if len(args) != 2:
raise MalError('Expected 2 arguments to "let*"')
new_env = env.new_child()
bindings, body = args
if (not isinstance(bindings, (t.MalVector, t.MalList))
or len(bindings.items) % 2 != 0):
raise MalError(
'Expected let* bindings to be even length list')
for i in range(0, len(bindings.items) // 2 + 1, 2):
name, value = bindings.items[i:i + 2]
if not isinstance(name, t.MalSymbol):
raise MalError('Expected symbol name in let* binding')
new_env[name.name] = EVAL(value, new_env)
env = new_env
in_ = body
continue
if f.name == 'do':
if not args:
raise MalError('Expected body in do expr')
eval_ast(t.MalList(args[:-1]), env)
in_ = args[-1]
continue
if f.name == 'if':
if len(args) not in (2, 3):
raise MalError('Expected 2 or 3 arguments to if')
cond, then, *else_ = args
if EVAL(cond, env).is_truthy():
in_ = then
elif else_:
in_ = else_[0]
else:
in_ = t.MalNil()
continue
if f.name == 'fn*':
if len(args) != 2:
raise MalError('Expected 2 arguments to fn*')
params, body = args
if not isinstance(params, (t.MalList, t.MalVector)):
raise MalError('Parameters must be list or vector')
if not all(isinstance(p, t.MalSymbol) for p in params.items):
raise MalError('Parameters must be symbols')
return t.MalTCOFunction(
ast=body,
params=params,
env=env,
fn=t.MalFunction(
_make_closure(
env,
[cast(t.MalSymbol, p).name
for p in params.items], body)),
)
f, *args = cast(t.MalList, eval_ast(in_, env)).items
if isinstance(f, t.MalFunction):
return f.fn(*args)
if isinstance(f, t.MalTCOFunction):
in_ = f.ast
binds = [
cast(t.MalSymbol, p).name
for p in cast(t.MalSequence, f.params).items
]
env = f.env.new_child(_make_fn_bindings(binds, list(args)))
continue
raise MalError(f'Value {pr_str(f)} is not callable')
def deref(*args: t.MalType) -> t.MalType:
if len(args) != 1 or not isinstance(args[0], t.MalAtom):
raise MalError('Expected deref argument to be atom')
return args[0].inner
def count(*args: t.MalType) -> t.MalType:
if len(args) != 1 or not isinstance(args[0], (t.MalSequence, t.MalNil)):
raise MalError('Expected argument to count to be sequence')
if isinstance(args[0], t.MalNil):
return t.MalInt(0)
return t.MalInt(len(args[0].items))
def read_string(*args: t.MalType) -> t.MalType:
if len(args) != 1 or not isinstance(args[0], t.MalString):
raise MalError('Expected read-string arg to be string')
return read_str(args[0].value)
def empty_p(*args: t.MalType) -> t.MalType:
if len(args) != 1 or not isinstance(args[0], t.MalSequence):
raise MalError('Expected argument to empty? to be sequence')
return t.MalBool(len(args[0].items) == 0)
def atom(*args: t.MalType) -> t.MalType:
if len(args) != 1:
raise MalError('Expected one argument to atom')
return t.MalAtom(args[0])
def evil(*args: t.MalType) -> t.MalType:
if len(args) != 1:
raise MalError('Expected one argument to eval')
return EVAL(args[0])
def _cmp_fn(*args: t.MalType) -> t.MalType:
try:
return t.MalBool(all(op(a, b) for a, b in _pairwise(args)))
except TypeError:
types = ', '.join([type(v).__name__ for v in args])
raise MalError(f'Cannot compare values of types {types}')
def reset(*args: t.MalType) -> t.MalType:
if len(args) != 2 or not isinstance(args[0], t.MalAtom):
raise MalError('Expected atom and value as arguments to reset!')
args[0].inner = args[1]
return args[1]
