def _Closure(self, c):
closed_over_literal = any(
map(lambda x: not isinstance(x, S.Name), c.closed_over()))
if not closed_over_literal:
return c
#Find procedure being closed over
proc_name = c.body().id
proc = self.procedures[proc_name]
proc_args = proc.formals()
closed_args = c.closed_over()
#Construct new set of arguments, with literals closed over removed
replaced_args = proc_args[:-len(closed_args)]
replaced_closed_over = []
#Also record what replacements to make
replacement = {}
for orig_arg, closed_arg in zip(proc_args[-len(closed_args):],
closed_args):
if isinstance(closed_arg, S.Name):
replaced_args.append(orig_arg)
replaced_closed_over.append(closed_arg)
else:
replacement[orig_arg.id] = closed_arg
#If we are only closing over literals, we will return a name
#rather than a reduced closure. Check.
fully_opened = len(replacement) == len(closed_args)
replaced_stmts = [
S.substituted_expression(si, replacement) \
for si in proc.body()]
replaced_name = S.Name(proc_name + self.name_supply.next())
self.propagated.append(
S.Procedure(replaced_name, replaced_args, replaced_stmts))
if fully_opened:
return replaced_name
else:
return S.Closure(replaced_closed_over, replaced_name)
def _Lambda(self, e):
fn = S.Name(self.names.next())
self.rewrite_children(e)
body = S.Return(e.parameters[0])
self.proclist.append(S.Procedure(fn, e.variables, [body]))
return fn
def _Apply(self, ast):
fn_id = ast.function().id
if fn_id in self.applies:
args = ast.arguments()
arity = len(args)
return S.Apply(S.Name(fn_id + str(arity)), args)
else:
return ast
def make_name(arg):
if not isinstance(arg, S.Tuple):
return arg
else:
made_name = S.Name(names.next())
assembled = S.Bind(S.Tuple(*[make_name(x) for x in arg]),
made_name)
disassembly.insert(0, assembled)
return made_name
def _Return(self, stmt):
e = self.rewrite(stmt.value())
if isinstance(e, S.Name):
stmt.parameters = [e]
self.emit(stmt)
return
# If we're returning a tuple, we always copy the value into a return
# variable. We may undo this later on, for entry-point procedures.
ret = S.Name("result")
self.emit(S.Bind(ret, e))
stmt.parameters = [ret]
self.emit(stmt)
def _Bind(self, stmt):
var = stmt.binder()
varNames = [x.id for x in flatten(var)]
operation = S.substituted_expression(stmt.value(), self.env)
for name in varNames:
if name not in self.exceptions:
rename = '%s_%s' % (name, self.serial.next())
else:
rename = name
self.env[name] = S.Name(rename)
result = S.Bind(S.substituted_expression(var, self.env), operation)
return result
def _Lambda(self, e):
_ClosureRecursion._Lambda(self, e)
formals = [v.id for v in flatten(e.formals())]
# Take the free variable list, stick it in a set to make sure we don't
# duplicate a variable, and then put it back in a list to make sure
# it's got a defined ordering, which sets don't have
free = list(
set([
v for v in S.free_variables(e.body(), formals) if v in self.env
]))
if free:
bound = [S.Name("_K%d" % i) for i in range(len(free))]
body = S.substituted_expression(e.body(), dict(zip(free, bound)))
e.parameters = [body]
e.variables = e.variables + bound
return S.Closure([S.Name(x) for x in free], e)
else:
return e
def _Apply(self, ast):
fn_id = ast.function().id
arity = -1
if fn_id in self.applies:
args = ast.arguments()
arity = len(args)
elif fn_id in self.binders:
arity = self.arity
assert (arity > 0)
if arity > 0:
return S.Apply(S.Name(fn_id + str(arity)), ast.arguments())
else:
return ast
def _Expression(self, e):
subexpressions = e.parameters
e.parameters = []
for sub in subexpressions:
sub = self.rewrite(sub)
# XXX It doesn't seem right to include Closure on this list
# of "atomic" values. But phase_assignment breaks if I
# don't do this.
if not isinstance(sub, (S.Name, S.Literal, S.Closure)):
tn = S.Name(self.names.next())
self.emit(S.Bind(tn, sub))
else:
tn = sub
e.parameters.append(tn)
return e
def _Procedure(self, ast):
binders = [v.id
for v in flatten(ast.variables)] # NOTE: this includes name
_ClosureRecursion._Procedure(self, ast)
# Take the free variable list, stick it in a set to make sure we don't
# duplicate a variable, and then put it back in a list to make sure
# it's got a defined ordering, which sets don't have
free = list(
set([
v for v in S.free_variables(ast.body(), binders)
if v in self.env
]))
if free:
bound = [S.Name("_K%d" % i) for i in range(len(free))]
ast.variables = ast.variables + bound
ast.parameters = S.substituted_expression(ast.parameters,
dict(zip(free, bound)))
# Transform recursive calls of this procedure within its own body.
recursive = _ClosureRecursion(self.env)
self.env[ast.name().id] = bound
ast.parameters = recursive.rewrite(ast.parameters)
# Register rewrite for calls to this procedure in later
# parts of the defining scope
self.env[ast.name().id] = S.Closure([S.Name(x) for x in free],
ast.name())
# else:
# self.locally_bound([ast.name()])
return ast
def _Return(self, stmt):
e = self.rewrite(stmt.value())
if isinstance(e, S.Name):
# If we're returning one of the procedure formals unchanged,
# we need to copy its value into a return variable.
# Here is where we check:
if e.id not in self.formals:
#No need to copy value into a return variable
stmt.parameters = [e]
self.emit(stmt)
return
# If we're returning a tuple, we always copy the value into a return
# variable. We may undo this later on, for entry-point procedures.
ret = S.Name("result")
self.emit(S.Bind(ret, e))
stmt.parameters = [ret]
self.emit(stmt)
def build_cast(cast_name, args):
"Helper function to build cast expressions"
return S.Apply(S.Name(cast_name), args)
def _Map(self, ast):
args = ast.parameters
arity = len(args) - 1
assert (arity > 0)
return S.Apply(S.Name('map' + str(arity)), args)
def mark_user(x):
return S.mark_user(S.Name(x)).id
