def test_letrec_odd_even(self):
from util import n
odd, even = MacroVar('odd'), MacroVar('even')
eq_(
eval(
letrec([(odd, macro([n], if_(eq(n, 0), 0, even(sub(n, 1))))),
(even, macro([n], if_(eq(n, 0), 1, odd(sub(n, 1)))))],
odd(3))), 1)
def test_kleene2(self):
f, kleene = MacroVar('f'), MacroVar('kleene')
_ = DummyVar('_')
item = Var('item')
fun = macro((item, ),
letrec([(f, macrorules(((), item, f()), ((), nullword)))],
f()))
eq_(eval(let([(kleene, fun)], set_text('ab'), kleene(char(_)))), True)
def alpha(self, env, compiler):
new_env = env.extend()
for var, value in self.bindings:
if isinstance(value, Rules):
if not isinstance(var, Const):
new_var = compiler.new_var(LamdaVar(var.name))
else:
new_var = compiler.new_var(ConstLamdaVar(var.name))
elif isinstance(value, Lamda):
if not isinstance(var, Const):
new_var = compiler.new_var(LamdaVar(var.name))
else:
new_var = compiler.new_var(ConstLamdaVar(var.name))
elif isinstance(value, MacroRules):
if not isinstance(var, Const):
new_var = compiler.new_var(MacroVar(var.name))
else:
new_var = compiler.new_var(ConstMacroVar(var.name))
else:
new_var = compiler.new_var(var)
if isinstance(var, Const):
new_var.assigned = True
env[var ] = new_var
alphaed_body = self.body.alpha(new_env, compiler)
assign_bindings = tuple(Assign(new_env[var], value.alpha(env, compiler))
for var, value in self.bindings)
return begin(*(assign_bindings+(alphaed_body,)))
def test_letrec_fac(self):
from util import m, n
fac = MacroVar('fac')
eq_(
eval(
letrec([
(fac, macro([n], if_(eq(n, 1), 1, mul(n, fac(sub(n, 1))))))
], fac(3))), 6)
def test_chars(self):
x, cs, chars = LogicVar('x'), Var('cs'), MacroVar('chars')
x1 = Var('x')
eq_(
eval(
let([(chars, lamda(
(x1, cs), begin(char(x1), contain(cs, x1))))],
parse_text(chars(x, 'a'), 'a'), getvalue(x))), 'a')
def test_macro6(self):
n, act, ntimes = Var('n'), Var('act'), MacroVar('ntimes')
eq_(
eval(
letrec([(ntimes,
macro((n, act),
if_(eq(n, 0), 1,
begin(act, ntimes(sub(n, 1), act)))))],
ntimes(3, println(1)))), 1)
def testletdouble1(self):
x, f = Var('x'), MacroVar('f')
eq_(eval(let([(f, macro([x], add(x, x)))], f(1))), 2)
def test_letrec3(self):
x, f = Var('x'), MacroVar('f')
eq_(
eval(
letrec([(f, macro((x, ), if_(eq(x, 1), 1, f(sub(x, 1)))))],
f(2))), 1)
def xtest_letrec2(self):
x, f = Var('x'), MacroVar('f')
eq_(eval(letrec([(f, macro((x, ), f(1)))], f(2))), 1)
def test_macro5(self):
x, y, f = Const('x'), Const('y'), MacroVar('f')
eq_(eval(let([(f, macro((x, y), y, x, 1))], f(println(1), prin(2)))),
1)