def validate_get_or_set(self, subscript: ast.Subscript, index_node: ast.Index) -> IType:
"""
Verifies if the subscribed value is a sequence and if the index is valid to this sequence
:param subscript: the python ast subscript node
:param index_node: the subscript index
:return: the type of the accessed value if it is valid. Type.none otherwise.
"""
value = self.visit(subscript.value)
index = self.visit(index_node)
if isinstance(value, ast.Name):
value = self.get_symbol(value.id)
if isinstance(index, ast.Name):
index = self.get_symbol(index.id)
if not isinstance(index, tuple):
index = (index,)
# if it is a type hint, returns the outer type
if isinstance(value, IType) and all(isinstance(i, IType) for i in index):
return value
symbol_type: IType = self.get_type(value)
index_type: IType = self.get_type(index[0])
# only sequence types can be subscribed
if not isinstance(symbol_type, Collection):
self._log_error(
CompilerError.UnresolvedOperation(
subscript.lineno, subscript.col_offset,
type_id=symbol_type.identifier,
operation_id=Operator.Subscript)
)
return symbol_type
# the sequence can't use the given type as index
if not symbol_type.is_valid_key(index_type):
self._log_error(
CompilerError.MismatchedTypes(
subscript.lineno, subscript.col_offset,
actual_type_id=index_type.identifier,
expected_type_id=symbol_type.valid_key.identifier)
)
# it is setting a value in a sequence that doesn't allow reassign values
elif isinstance(subscript.ctx, ast.Store) and not symbol_type.can_reassign_values:
self._log_error(
CompilerError.UnresolvedOperation(
subscript.lineno, subscript.col_offset,
type_id=symbol_type.identifier,
operation_id=Operator.Subscript)
)
return symbol_type.item_type
def validate_slice(self, subscript: ast.Subscript, slice_node: ast.Slice) -> IType:
"""
Verifies if the subscribed value is a sequence and if the slice is valid to this sequence
:param subscript: the python ast subscript node
:param slice_node: the subscript slice
:return: the type of the accessed value if it is valid. Type.none otherwise.
"""
value = self.visit(subscript.value)
lower, upper, step = (self.get_type(value) for value in self.visit(slice_node))
if step is not Type.none:
# TODO: remove when slices with stride are implemented
raise NotImplementedError
# is not allowed to store into a slice
if isinstance(subscript.ctx, ast.Store):
self._log_error(
CompilerError.NotSupportedOperation(
subscript.lineno, subscript.col_offset,
symbol_id=Operator.Subscript
)
)
symbol_type: IType = self.get_type(value)
# only collection types can be subscribed
if not isinstance(symbol_type, Collection):
self._log_error(
CompilerError.UnresolvedOperation(
subscript.lineno, subscript.col_offset,
type_id=symbol_type.identifier,
operation_id=Operator.Subscript)
)
return Type.none
lower = lower if lower is not Type.none else symbol_type.valid_key
upper = upper if upper is not Type.none else symbol_type.valid_key
# TODO: remove when slices of other sequence types are implemented
if (not symbol_type.is_valid_key(lower)
or not symbol_type.is_valid_key(upper)
or (step is not Type.none and not symbol_type.is_valid_key(step))
):
actual: Tuple[IType, ...] = (lower, upper) if step is Type.none else (lower, upper, step)
self._log_error(
CompilerError.MismatchedTypes(
subscript.lineno, subscript.col_offset,
expected_type_id=[symbol_type.valid_key.identifier for value in actual],
actual_type_id=[value.identifier for value in actual]
)
)
else:
return symbol_type
return Type.none