def expand(cls, forms, var_env, func_env, macro_env):
if not isinstance(forms, Cons):
# If an atom is given, returns itself.
return forms
elif isinstance(forms.car,
Symbol): # and forms.car.value in macro_env:
# Gets symbol_name, package_name, and status_check.
macro_name, package_name, status_check = PackageManager.split_symbol_name(
forms.car.value)
# Gets the macro binded by the symbol.
# When package_name is None, the package becomes PackageManager.current_package.
try:
# Tries to get the function from lexical environment in current package.
macro = macro_env.find(macro_name)[macro_name]
except LookupError:
try:
macro = PackageManager.find(macro_name,
package_name,
status_check,
env='MACRO')[macro_name]
except LookupError:
return Cons(
forms.car,
cls.recusive_expand(forms.cdr, var_env, func_env,
macro_env))
return macro(forms.cdr, var_env, func_env, macro_env)
else:
return Cons(cls.expand(forms.car, var_env, func_env, macro_env),
cls.expand(forms.cdr, var_env, func_env, macro_env))
def __call__(self, forms, var_env, func_env, macro_env):
"""Behavior of BlockSpecialOperator.
"""
from clispy.evaluator import Evaluator
# throw is a param of lambda in call/cc.
lambda_forms = Cons(Cons(forms.car, Null()), forms.cdr)
# call/cc is used to control.
callcc = CallCC(Lambda(lambda_forms, var_env, func_env, macro_env))
return callcc(var_env, func_env, macro_env)
def __call__(self, forms, var_env, func_env, macro_env):
"""Behavior of FletSystemMacro.
"""
from clispy.expander import Expander
bindings, body = forms.car, forms.cdr
# Expands body recursively.
body = Expander.expand(body, var_env, macro_env, macro_env)
# The body of flet has an implicit progn.
forms = Cons(Symbol('FLET'), Cons(bindings, Cons(Cons(Symbol('PROGN'), body), Null())))
return forms
def __call__(self, forms, var_env, func_env, macro_env):
"""Behavior of BlockSystemMacro.
"""
from clispy.expander import Expander
name, body = forms.car, forms.cdr
# Expands body recursively.
body = Expander.expand(body, var_env, func_env, macro_env)
# The body of a block has an implicit progn.
forms = Cons(Symbol('BLOCK'), Cons(name, Cons(Cons(Symbol('PROGN'), body), Null())))
return forms
def __call__(self, forms, var_env, func_env, macro_env):
"""Behavior of LambdaSystemMacro.
"""
from clispy.expander import Expander
params, body = forms.car, forms.cdr
# Expands body recursively.
body = Expander.expand(body, var_env, func_env, macro_env)
# The body of a lambda has an implicit progn.
forms = Cons(Symbol('LAMBDA'), Cons(params, Cons(Cons(Symbol('PROGN'), body), Null())))
return forms
def __call__(self, forms, var_env, func_env, macro_env):
"""Behavior of IfSystemMacro.
"""
from clispy.expander import Expander
# If else_form is Null, then else_form is set to Null.
test_form, then_form, else_form = forms.car, forms.cdr.car, forms.cdr.cdr.car
# Expands body recursively.
test_form = Expander.expand(test_form, var_env, func_env, macro_env)
then_form = Expander.expand(then_form, var_env, func_env, macro_env)
else_form = Expander.expand(else_form, var_env, func_env, macro_env)
forms = Cons(Symbol('IF'), Cons(test_form, Cons(then_form, Cons(else_form, Null()))))
return forms
def __call__(self, forms, var_env, func_env, macro_env):
"""Behavior of FletSpecialOperator.
"""
from clispy.evaluator import Evaluator
bindings, body = forms.car, forms.cdr.car
funcs = []
exps = []
# For encompassing the function definitions themselves,
# a function environment is extended in advance.
local_func_env = func_env.extend()
while bindings is not Null():
func, exp = bindings.car.car, bindings.car.cdr
# Interns symbol that represents function name into current package.
PackageManager.intern(String(func.value))
funcs.append(func.value)
exp = Cons(Symbol('LAMBDA'), exp)
# The scope of the name bindings encompasses the function definitions
# themselves as well as the body.
exps.append(Evaluator.eval(exp, var_env, local_func_env,
macro_env))
bindings = bindings.cdr
# The bindings are in parallel.
local_func_env.update(zip(funcs, exps))
return Evaluator.eval(body, var_env, local_func_env, macro_env)
def __call__(self, forms, var_env, func_env, macro_env):
"""Behavior of FletSpecialOperator.
"""
from clispy.evaluator import Evaluator
bindings, body = forms.car, forms.cdr.car
funcs = []
exps = []
while bindings is not Null():
func, exp = bindings.car.car, bindings.car.cdr
# Interns symbol that represents function name into current package.
PackageManager.intern(String(func.value))
funcs.append(func.value)
exp = Cons(Symbol('LAMBDA'), exp)
# The scope of the name bindings dose not encompasse the function definitions.
exps.append(Evaluator.eval(exp, var_env, func_env, macro_env))
bindings = bindings.cdr
# The bindings are in parallel.
func_env = func_env.extend(params=funcs, args=exps)
return Evaluator.eval(body, var_env, func_env, macro_env)
def reverse(cls, args, last):
"""Reverses an element in args as Cons.
"""
while args is not Null():
last = Cons(args.car, last)
args = args.cdr
return last
def accumulate(cls, args, acc):
"""Accumulates an element in args as Cons to acc.
"""
while args is not Null():
acc = Cons(args.car, acc)
args = args.cdr
return acc
def __init__(self, proc):
from clispy.python import PyObject
self.ball = RuntimeWarning(
"Sorry, can't continue this continuation any longer.")
self.ball.retval = Null()
self.proc = proc
self.args = Cons(PyObject(Invoke(self)), Null())
def expand_hepler(cls, forms):
"""Expand quotes recursively.
"""
if not isinstance(forms, Cons): # An argument is not an instance of Cons, it is quoted.
return Cons(Symbol('QUOTE'), Cons(forms, Null()))
if forms.car is Symbol('UNQUOTE'): # Unquote (,).
return forms.cdr.car
elif isinstance(forms.car, Cons) and forms.car.car is Symbol('UNQUOTE-SPLICING'): # Unquote-splicing (,@).
return Cons(Symbol('APPEND'), Cons(forms.car.cdr.car, Cons(cls.expand_hepler(forms.cdr), Null())))
else: # Expands recursively and returns cons.
return Cons(Symbol('CONS'), Cons(cls.expand_hepler(forms.car), Cons(cls.expand_hepler(forms.cdr), Null())))
def recusive_expand(cls, rest_forms, var_env, func_env, macro_env):
"""Expand forms recursively.
"""
expanded_forms = Null()
while rest_forms is not Null():
expanded_forms = Cons(
cls.expand(rest_forms.car, var_env, func_env, macro_env),
expanded_forms)
rest_forms = rest_forms.cdr
return cls.reverse(expanded_forms, Null())
def __call__(self, forms, var_env, func_env, macro_env):
"""Behavior of DefmacroSystemMacro.
"""
from clispy.expander import Expander
name, params, body = forms.car, forms.cdr.car, forms.cdr.cdr
# Expands body, recursively.
body = Expander.expand(body, var_env, func_env, macro_env)
# The value of the last form executed is returned as the expansion of the macro.
body = Cons(Cons(Symbol('PROGN'), body), Null())
# The body of a defmacro has an implicit block.
forms = Cons(Symbol('DEFMACRO'), Cons(name, Cons(params, Cons(Cons(Symbol('BLOCK'), Cons(name, body)), Null()))))
return forms
def __call__(self, forms, var_env, func_env, macro_env):
"""Behavior of ConsSytemFunction.
"""
args = self.eval_forms(forms, var_env, func_env, macro_env)
return Cons(args.car, args.cdr.car)
def __call__(self, forms, var_env, func_env, macro_env):
"""Behavior of QuoteSystemMacro.
"""
# Retruns itself.
return Cons(Symbol('QUOTE'), forms)