def interactive():
print "PyPy Scheme interpreter"
ctx = ExecutionContext()
to_exec = ""
cont = False
while 1:
if cont:
ps = '.. '
else:
ps = '-> '
sys.stdout.write(ps)
to_exec += sys.stdin.readline()
if to_exec == "\n":
to_exec = ""
elif check_parens(to_exec):
try:
if to_exec == "":
print
raise SchemeQuit
print parse(to_exec)[0].eval(ctx).to_string()
except SchemeQuit, e:
break
except ContinuationReturn, e:
print e.result.to_string()
except SchemeException, e:
print "error: %s" % e
def entry_point(argv):
if len(argv) == 2:
code = open_file_as_stream(argv[1]).readall()
try:
t = parse(code)
except BacktrackException:
#(line, col) = e.error.get_line_column(code)
#expected = " ".join(e.error.expected)
print "parse error"
return 1
#this should not be necessary here
assert isinstance(t, list)
ctx = ExecutionContext()
try:
for sexpr in t:
try:
w_retval = sexpr.eval(ctx)
print w_retval.to_string()
except ContinuationReturn, e:
print e.result.to_string()
except SchemeQuit, e:
return 0
return 0
def entry_point(argv):
if len(argv) == 2:
code = open_file_as_stream(argv[1]).readall()
try:
t = parse(code)
except BacktrackException:
#(line, col) = e.error.get_line_column(code)
#expected = " ".join(e.error.expected)
print "parse error"
return 1
#this should not be necessary here
assert isinstance(t, list)
ctx = ExecutionContext()
try:
for sexpr in t:
try:
w_retval = sexpr.eval(ctx)
print w_retval.to_string()
except ContinuationReturn, e:
print e.result.to_string()
except SchemeQuit, e:
return 0
return 0
def test_evaluator():
ctx = ExecutionContext()
eval_(ctx, "(define a 0)")
w_obj = parse("(let () (set! a 42) a)")[0]
(w_expr, new_ctx) = w_obj.eval_tr(ctx)
assert ctx.get("a").to_number() == 42
assert isinstance(w_expr, W_Symbol)
assert new_ctx is not ctx
assert isinstance(new_ctx, ExecutionContext)
(w_obj, newer_ctx) = w_expr.eval_tr(new_ctx)
assert isinstance(w_obj, W_Number)
assert w_obj.to_number() == 42
assert newer_ctx is None
def test_evaluator():
ctx = ExecutionContext()
eval_(ctx, "(define a 0)")
w_obj = parse("(let () (set! a 42) a)")[0]
(w_expr, new_ctx) = w_obj.eval_tr(ctx)
assert ctx.get("a").to_number() == 42
assert isinstance(w_expr, W_Symbol)
assert new_ctx is not ctx
assert isinstance(new_ctx, ExecutionContext)
(w_obj, newer_ctx) = w_expr.eval_tr(new_ctx)
assert isinstance(w_obj, W_Number)
assert w_obj.to_number() == 42
assert newer_ctx is None
def eval_noctx(expr):
return parse(expr)[0].eval(ExecutionContext())
def eval_(ctx, expr):
return parse(expr)[0].eval(ctx)
def parse_(expr):
return parse(expr)[0]
def eval_(ctx, expr):
try:
return parse(expr)[0].eval(ctx)
except ContinuationReturn, e:
return e.result
def parse_sexpr(expr):
return parse(expr)[0]
def __init__(self, w_obj=None):
self.obj = w_obj
OPERATION_MAP = {}
for mod in (ssobject, syntax, procedure, macro):
for obj_name in dir(mod):
obj = getattr(mod, obj_name)
try:
issubclass(obj, ssobject.W_Callable)
OPERATION_MAP[obj._symbol_name] = obj(obj._symbol_name)
except (TypeError, AttributeError):
pass
de_file = py.magic.autopath().dirpath().join("r5rs_derived_expr.ss")
de_code = de_file.read()
de_expr_lst = parse(de_code)
class ExecutionContext(object):
"""Execution context implemented as a dict.
{ "IDENTIFIER": Location(W_Root()) }
"""
def __init__(self, globalscope=None, scope=None, closure=False,
cont_stack=None):
if scope is None:
self.scope = {}
else:
self.scope = scope
self.closure = closure
def eval_(ctx, expr):
return parse(expr)[0].eval(ctx)
def parse_(expr):
return parse(expr)[0]
def eval_noctx(expr):
return parse(expr)[0].eval(ExecutionContext())
def eval_noctx(expr):
return parse(expr)[0].eval(None)
def eval_(ctx, expr):
try:
return parse(expr)[0].eval(ctx)
except ContinuationReturn, e:
return e.result
