def testSexpParsing(self):
"""Test parsing S-expressions.
"""
cases = [("x", tsym("x")), \
("(x)", from_python_list([tsym("x")])), \
("(x y)", from_python_list([tsym("x"), tsym("y")])), \
("(x (y))", from_python_list([tsym("x"), [tsym("y")]])), \
("(x . y)", cons(tsym("x"), tsym("y"))), \
("(x y . z)", cons(tsym("x"), cons(tsym("y"), tsym("z")))), \
("(x (y . z) w)", cons(tsym("x"),
cons(cons(tsym("y"), tsym("z")),
cons(tsym("w"), NIL))))]
for case in cases:
sexp = self.parser.parse(self.tokenizer.tokenize(case[0] + '\n'))[0]
self.assertEqual(sexp, case[1])
def compile_namedlet(self, exp, env, cont, istail=False):
"""Compile a named let form. At runtime a new frame will
be created and the closure will be defined in such frame
and applied to the arguments listed in the bindings.
"""
def got_define(define_code):
nonlocal compiled_define_code
compiled_define_code = define_code
apply_form = cons(proc_name, from_python_list(vall))
return bounce(self.compile_call, apply_form, newenv, got_apply, istail=istail)
def got_apply(apply_code):
code = [
(inst_extenv,),
] + compiled_define_code + \
apply_code + [
(inst_killenv,),
]
return bounce(cont, code)
proc_name = cadr(exp)
varl = let_vars(caddr(exp))
vall = let_vals(caddr(exp))
lambda_form = lib_append(
lib_list(
tsym('lambda'), from_python_list(varl)),
cdddr(exp))
define_form = lib_list(tsym('define'), proc_name, lambda_form)
newenv = Frame([proc_name], outer=env)
compiled_define_code = None
return bounce(self.compile_define, define_form, newenv, got_define)
def inst_tailcall(vm):
"""Make a tail call to closure in VAL with ARGS.
"""
closure = vm.regs[vm.REG_VAL]
if not isinstance(closure, Closure):
raise SchemeError('not a callable procedure')
if closure.isprim:
vm.regs[vm.REG_VAL] = closure.primcall(vm.regs[vm.REG_ARGS])
vm.regs[vm.REG_PC] += 1
else:
# bind parameters to arguments
if closure.isvararg:
# the last parameter is bound to a list
args = vm.regs[vm.REG_ARGS][:closure.arity[0] - 1]
args.append(from_python_list(vm.regs[vm.REG_ARGS][closure.arity[0] - 1:]))
closure.check_arity(len(args))
frm = Frame(args, closure.env)
else:
closure.check_arity(len(vm.regs[vm.REG_ARGS]))
frm = Frame(vm.regs[vm.REG_ARGS], closure.env)
vm.regs[vm.REG_ENV] = frm
# jump to the closure code
vm.code = closure.body
vm.codelen = len(vm.code)
vm.regs[vm.REG_PC] = 0
def got_define(define_code):
nonlocal compiled_define_code
compiled_define_code = define_code
apply_form = cons(proc_name, from_python_list(vall))
return bounce(self.compile_call, apply_form, newenv, got_apply, istail=istail)
