def visit_Call_Aggregate_only(self, node: ast.Call):
'''
- (acc lambda): the accumulator is set to the first element, and the lambda is called to
update it after that. This is called `agg_only`.
'''
agg_lambda = node.args[0]
# Get the sequence we are calling against and the accumulator
if not isinstance(node.func, ast.Attribute):
raise BaseException("Wrong type of function")
seq = self.as_sequence(node.func.value)
accumulator, accumulator_scope = self.create_accumulator(seq)
# We have to do a simple if statement here so that the first time through we can set the
# accumulator, and the second time we can add to it.
is_first_iter = crep.cpp_variable(unique_name("is_first"),
self._gc.current_scope(),
cpp_type=ctyp.terminal('bool'),
initial_value=crep.cpp_value(
'true', self._gc.current_scope(),
ctyp.terminal('bool')))
accumulator_scope.declare_variable(is_first_iter)
# Set the scope where we will be doing the accumulation
sv = seq.sequence_value()
if isinstance(sv, crep.cpp_sequence):
self._gc.set_scope(sv.iterator_value().scope()[-1])
else:
self._gc.set_scope(sv.scope())
# Code up if statement to select out the first element.
if_first = statement.iftest(is_first_iter)
self._gc.add_statement(if_first)
self._gc.add_statement(
statement.set_var(
is_first_iter,
crep.cpp_value("false", self._gc.current_scope(),
ctyp.terminal('bool'))))
# Set the accumulator
self._gc.add_statement(
statement.set_var(accumulator, seq.sequence_value()))
self._gc.pop_scope()
# Now do the if statement and make the call to calculate the accumulation.
self._gc.add_statement(statement.elsephrase())
call = ast.Call(
func=agg_lambda,
args=[accumulator.as_ast(),
seq.sequence_value().as_ast()])
self._gc.add_statement(
statement.set_var(accumulator, self.get_rep(call)))
# Finally, since this is a terminal, we need to pop off the top.
self._gc.set_scope(accumulator_scope)
# Cache the results in our result in case we are skipping nodes in the AST.
node.rep = accumulator
self._result = accumulator
def visit_BinOp(self, node):
'An in-line add'
left = self.get_rep(node.left)
right = self.get_rep(node.right)
# TODO: Turn this into a table lookup rather than the same thing repeated over and over
s = deepest_scope(left, right).scope()
if isinstance(node.op, ast.Add):
r = crep.cpp_value(
"({0}+{1})".format(left.as_cpp(), right.as_cpp()), s,
left.cpp_type())
elif isinstance(node.op, ast.Div):
r = crep.cpp_value(
"({0}/{1})".format(left.as_cpp(), right.as_cpp()), s,
left.cpp_type())
elif isinstance(node.op, ast.Sub):
r = crep.cpp_value(
"({0}-{1})".format(left.as_cpp(), right.as_cpp()), s,
left.cpp_type())
elif isinstance(node.op, ast.Mult):
r = crep.cpp_value(
"({0}*{1})".format(left.as_cpp(), right.as_cpp()), s,
left.cpp_type())
else:
raise BaseException(
"Binary operator {0} is not implemented.".format(type(
node.op)))
# Cache the result to push it back further up.
node.rep = r
self._result = r
def test_deepest_scope_equal():
g = generated_code()
s1 = statement.iftest("true")
s2 = statement.set_var("v1", "true")
g.add_statement(s1)
scope_1 = g.current_scope()
v1 = crep.cpp_value("v1", scope_1, ctyp.terminal('int'))
v2 = crep.cpp_value("v2", scope_1, ctyp.terminal('int'))
assert v1 == deepest_scope(v1, v2)
assert v2 == deepest_scope(v2, v1)
def visit_BoolOp(self, node):
'''A bool op like And or Or on a set of values
This is a bit more complex than just "anding" things as we want to make sure to short-circuit the
evaluation if we need to.
'''
# The result of this test
result = crep.cpp_variable(unique_name('bool_op'),
self._gc.current_scope(),
cpp_type='bool')
self._gc.declare_variable(result)
# How we check and short-circuit depends on if we are doing and or or.
check_expr = result.as_cpp() if type(
node.op) == ast.And else '!{0}'.format(result.as_cpp())
check = crep.cpp_value(check_expr,
self._gc.current_scope(),
cpp_type='bool')
first = True
scope = self._gc.current_scope()
for v in node.values:
if not first:
self._gc.add_statement(statement.iftest(check))
rep_v = self.get_rep(v)
self._gc.add_statement(statement.set_var(result, rep_v))
if not first:
self._gc.set_scope(scope)
first = False
# Cache result variable so those above us have something to use.
self._result = result
node.rep = result
def visit_Call_Member(self, call_node):
'Method call on an object'
# If this is a special type of Function call that we need to work with, split out here
# before any processing is done.
if (call_node.func.attr == "Aggregate"):
return self.visit_Call_Aggregate(call_node)
# Visit everything down a level.
# TODO: Support arguments to functions like this.
self.generic_visit(call_node)
# figure out what we are calling against, and the
# method name we are going to be calling against.
calling_against = self.get_rep(call_node.func.value)
function_name = call_node.func.attr
if not isinstance(calling_against, crep.cpp_value):
# We didn't use get_rep_value above because now we can make a better error message.
raise BaseException(
"Do not know how to call '{0}' on '{1}'".format(
function_name,
type(calling_against).__name__))
# We support member calls that directly translate only. Here, for example, this is only for
# obj.pt() or similar. The translation is direct.
# TODO: The iterator might be in an argument, so passing calling_against here may not be ok.
# TODO: We have no type system, who knows what type this function returns. Assume double.
c_stub = calling_against.as_cpp() + (
"->" if calling_against.is_pointer() else ".")
result_type = determine_type_mf(calling_against.cpp_type(),
function_name)
self._result = crep.cpp_value(c_stub + function_name + "()",
calling_against.scope(), result_type)
def create_accumulator(self,
seq: crep.cpp_sequence,
initial_value=None,
acc_type=None):
'Helper to create an accumulator for the Aggregate function'
accumulator_type = acc_type
if accumulator_type is None:
sv = seq.sequence_value()
if not isinstance(sv, crep.cpp_value):
raise BaseException(
"Do not know how to accumulate a sequence!")
accumulator_type = sv.cpp_type()
if not check_accumulator_type(accumulator_type):
raise BaseException(
"Aggregate over a sequence of type '{0}' is not supported.".
format(str(accumulator_type)))
# Getting the scope level right is tricky. If this is a straight sequence of items, then we want the sequence level.
# But if this is a sequence of sequences, we are aggregating over the sequence itself. So we need to do it one level
# up from where the iterator is running on the interior sequence.
seq_val = seq.sequence_value()
if isinstance(seq_val, crep.cpp_sequence):
accumulator_scope = seq_val.iterator_value().scope()[-1]
else:
accumulator_scope = seq.iterator_value().scope()[-1]
accumulator = crep.cpp_variable(
unique_name("aggResult"),
accumulator_scope,
accumulator_type,
initial_value=initial_value if initial_value is not None else
crep.cpp_value(accumulator_type.default_value(),
self._gc.current_scope(), accumulator_type))
accumulator_scope.declare_variable(accumulator)
return accumulator, accumulator_scope
def visit_First(self, node):
'We are in a sequence. Take the first element of the sequence and use that for future things.'
# Make sure we are in a loop.
seq = self.as_sequence(node.source)
# The First terminal works by protecting the code with a if (first_time) {} block.
# We need to declare the first_time variable outside the block where the thing we are
# looping over here is defined. This is a little tricky, so we delegate to another method.
loop_scope = seq.iterator_value().scope()
outside_block_scope = loop_scope[-1]
# Define the variable to track this outside that block.
is_first = crep.cpp_variable(unique_name('is_first'),
outside_block_scope,
cpp_type=ctyp.terminal('bool'),
initial_value=crep.cpp_value(
'true', self._gc.current_scope(),
ctyp.terminal('bool')))
outside_block_scope.declare_variable(is_first)
# Now, as long as is_first is true, we can execute things inside this statement.
# The trick is putting the if statement in the right place. We need to locate it just one level
# below where we defined the scope above.
s = statement.iftest(is_first)
s.add_statement(
statement.set_var(
is_first,
crep.cpp_value('false',
top_level_scope(),
cpp_type=ctyp.terminal('bool'))))
sv = seq.sequence_value()
if isinstance(sv, crep.cpp_sequence):
self._gc.set_scope(sv.iterator_value().scope()[-1])
else:
self._gc.set_scope(sv.scope())
self._gc.add_statement(s)
# If we just found the first sequence in a sequence, return that.
# Otherwise return a new version of the value.
first_value = sv if isinstance(
sv, crep.cpp_sequence) else sv.copy_with_new_scope(
self._gc.current_scope())
node.rep = first_value
self._result = first_value
def process_ast_node(visitor, gc, call_node: ast.Call):
r'''Inject the proper code into the output stream to deal with this C++ code.
We expect this to be run on the back-end of the system.
visitor - The node visitor that is converting the code into C++
gc - the generated code object that we fill with actual code
call_node - a Call ast node, with func being a CPPCodeValue.
Result:
representation - A value that represents the output
'''
# We write everything into a new scope to prevent conflicts. So we have to declare the result ahead of time.
cpp_ast_node = call_node.func
result_rep = cpp_ast_node.result_rep(gc.current_scope())
gc.declare_variable(result_rep)
# Include files
for i in cpp_ast_node.include_files:
gc.add_include(i)
# Build the dictionary for replacement for the object we are calling
# against, if any.
repl_list = []
if cpp_ast_node.replacement_instance_obj is not None:
repl_list += [
(cpp_ast_node.replacement_instance_obj[0],
visitor.resolve_id(
cpp_ast_node.replacement_instance_obj[1]).rep.as_cpp())
]
# Process the arguments that are getting passed to the function
for arg, dest in zip(cpp_ast_node.args, call_node.args):
rep = visitor.get_rep(dest)
repl_list += [(arg, rep.as_cpp())]
# Emit the statements.
blk = statements.block()
visitor._gc.add_statement(blk)
for s in cpp_ast_node.running_code:
l = s
for src, dest in repl_list:
l = l.replace(src, str(dest))
blk.add_statement(statements.arbitrary_statement(l))
# Set the result and close the scope
blk.add_statement(
statements.set_var(
result_rep,
cpp_value(cpp_ast_node.result, gc.current_scope(),
result_rep.cpp_type())))
gc.pop_scope()
return result_rep
def visit_Subscript(self, node):
'Index into an array. Check types, as tuple indexing can be very bad for us'
v = self.get_rep(node.value)
if not isinstance(v, crep.cpp_collection):
raise BaseException(
"Do not know how to take the index of type '{0}'".format(
v.cpp_type()))
index = self.get_rep(node.slice)
node.rep = crep.cpp_value("{0}.at({1})".format(v.as_cpp(),
index.as_cpp()),
self._gc.current_scope(),
cpp_type=v.get_element_type())
self._result = node.rep
def visit_Compare(self, node):
'A compare between two things. Python supports more than that, but not implemented yet.'
if len(node.ops) != 1:
raise BaseException("Do not support 1 < a < 10 comparisons yet!")
left = self.get_rep(node.left)
right = self.get_rep(node.comparators[0])
r = crep.cpp_value(
'({0}{1}{2})'.format(left.as_cpp(),
compare_operations[type(node.ops[0])],
right.as_cpp()), self._gc.current_scope(),
ctyp.terminal("bool"))
node.rep = r
self._result = r
def make_sequence_from_collection(self, rep):
'''
Take a collection and produce a sequence. Eventually this should likely be some sort of
plug-in architecture. But for now, we will just assume everything looks like a vector. When
it comes time for a new type, this is where it should go.
'''
element_type = rep.cpp_type().element_type()
iterator_value = crep.cpp_value(unique_name("i_obj"), None,
element_type)
l = statement.loop(iterator_value, crep.dereference_var(rep))
self._gc.add_statement(l)
iterator_value.reset_scope(self._gc.current_scope())
# For a new sequence like this the sequence and iterator value are the same
return crep.cpp_sequence(iterator_value, iterator_value)
def visit_function_ast(self, call_node):
'Drop-in replacement for a function'
# Get the arguments
cpp_func = call_node.func
arg_reps = [self.get_rep_value(a) for a in call_node.args]
# Code up a call
# TODO: The iterator might not be Note.
r = crep.cpp_value('{0}({1})'.format(
cpp_func.cpp_name, ','.join(a.as_cpp() for a in arg_reps)),
self._gc.current_scope(),
cpp_type=cpp_func.cpp_return_type)
# Include files and return the resulting expression
for i in cpp_func.include_files:
self._gc.add_include(i)
call_node.rep = r
return r
def visit_Str(self, node):
node.rep = crep.cpp_value('"{0}"'.format(node.s),
self._gc.current_scope(),
ctyp.terminal("string"))
self._result = node.rep
def visit_Num(self, node):
node.rep = crep.cpp_value(node.n, self._gc.current_scope(),
guess_type_from_number(node.n))
self._result = node.rep