gtsam/wrap/gtwrap/template_instantiator/helpers.py

301 lines
12 KiB
Python

"""Various helpers for instantiation."""
import itertools
from copy import deepcopy
from typing import List, Sequence, Union
import gtwrap.interface_parser as parser
ClassMembers = Union[parser.Constructor, parser.Method, parser.StaticMethod,
parser.GlobalFunction, parser.Operator, parser.Variable,
parser.Enum]
InstantiatedMembers = Union['InstantiatedConstructor', 'InstantiatedMethod',
'InstantiatedStaticMethod',
'InstantiatedGlobalFunction']
def is_scoped_template(template_typenames: Sequence[str],
str_arg_typename: str):
"""
Check if the template given by `str_arg_typename` is a scoped template e.g. T::Value,
and if so, return what template from `template_typenames` and
the corresponding index matches the scoped template correctly.
"""
for idx, template in enumerate(template_typenames):
if "::" in str_arg_typename and \
template in str_arg_typename.split("::"):
return template, idx
return False, -1
def instantiate_type(
ctype: parser.Type,
template_typenames: Sequence[str],
instantiations: Sequence[parser.Typename],
cpp_typename: parser.Typename,
instantiated_class: 'InstantiatedClass' = None) -> parser.Type:
"""
Instantiate template typename for `ctype`.
Args:
ctype: The original argument type.
template_typenames: List of strings representing the templates.
instantiations: List of the instantiations of the templates in `template_typenames`.
cpp_typename: Full-namespace cpp class name of this instantiation
to replace for arguments of type named `This`.
instiated_class: The instantiated class which, if provided,
will be used for instantiating `This`.
Returns:
If `ctype`'s name is in the `template_typenames`, return the
corresponding type to replace in `instantiations`.
If ctype name is `This`, return the new typename `cpp_typename`.
Otherwise, return the original ctype.
"""
# make a deep copy so that there is no overwriting of original template params
ctype = deepcopy(ctype)
# Check if the return type has template parameters as the typename's name
if ctype.typename.instantiations:
for idx, instantiation in enumerate(ctype.typename.instantiations):
if instantiation.name in template_typenames:
template_idx = template_typenames.index(instantiation.name)
ctype.typename.instantiations[idx].name =\
instantiations[template_idx]
str_arg_typename = str(ctype.typename)
# Check if template is a scoped template e.g. T::Value where T is the template
scoped_template, scoped_idx = is_scoped_template(template_typenames,
str_arg_typename)
# Instantiate templates which have enumerated instantiations in the template.
# E.g. `template<T={double}>`.
# Instantiate scoped templates, e.g. T::Value.
if scoped_template:
# Create a copy of the instantiation so we can modify it.
instantiation = deepcopy(instantiations[scoped_idx])
# Replace the part of the template with the instantiation
instantiation.name = str_arg_typename.replace(scoped_template,
instantiation.name)
return parser.Type(
typename=instantiation,
is_const=ctype.is_const,
is_shared_ptr=ctype.is_shared_ptr,
is_ptr=ctype.is_ptr,
is_ref=ctype.is_ref,
is_basic=ctype.is_basic,
)
# Check for exact template match.
elif str_arg_typename in template_typenames:
idx = template_typenames.index(str_arg_typename)
return parser.Type(
typename=instantiations[idx],
is_const=ctype.is_const,
is_shared_ptr=ctype.is_shared_ptr,
is_ptr=ctype.is_ptr,
is_ref=ctype.is_ref,
is_basic=ctype.is_basic,
)
# If a method has the keyword `This`, we replace it with the (instantiated) class.
elif str_arg_typename == 'This':
# Check if the class is template instantiated
# so we can replace it with the instantiated version.
if instantiated_class:
name = instantiated_class.original.name
namespaces_name = instantiated_class.namespaces()
namespaces_name.append(name)
cpp_typename = parser.Typename(
namespaces_name,
instantiations=instantiated_class.instantiations)
return parser.Type(
typename=cpp_typename,
is_const=ctype.is_const,
is_shared_ptr=ctype.is_shared_ptr,
is_ptr=ctype.is_ptr,
is_ref=ctype.is_ref,
is_basic=ctype.is_basic,
)
# Case when 'This' is present in the type namespace, e.g `This::Subclass`.
elif 'This' in str_arg_typename:
# Check if `This` is in the namespaces
if 'This' in ctype.typename.namespaces:
# Simply get the index of `This` in the namespace and
# replace it with the instantiated name.
namespace_idx = ctype.typename.namespaces.index('This')
ctype.typename.namespaces[namespace_idx] = cpp_typename.name
# Else check if it is in the template namespace, e.g vector<This::Value>
else:
for idx, instantiation in enumerate(ctype.typename.instantiations):
if 'This' in instantiation.namespaces:
ctype.typename.instantiations[idx].namespaces = \
cpp_typename.namespaces + [cpp_typename.name]
return ctype
else:
return ctype
def instantiate_args_list(
args_list: Sequence[parser.Argument],
template_typenames: Sequence[parser.template.Typename],
instantiations: Sequence, cpp_typename: parser.Typename):
"""
Instantiate template typenames in an argument list.
Type with name `This` will be replaced by @p `cpp_typename`.
@param[in] args_list A list of `parser.Argument` to instantiate.
@param[in] template_typenames List of template typenames to instantiate,
e.g. ['T', 'U', 'V'].
@param[in] instantiations List of specific types to instantiate, each
associated with each template typename. Each type is a parser.Typename,
including its name and full namespaces.
@param[in] cpp_typename Full-namespace cpp class name of this instantiation
to replace for arguments of type named `This`.
@return A new list of parser.Argument which types are replaced with their
instantiations.
"""
instantiated_args = []
for arg in args_list:
new_type = instantiate_type(arg.ctype, template_typenames,
instantiations, cpp_typename)
instantiated_args.append(
parser.Argument(name=arg.name, ctype=new_type,
default=arg.default))
return instantiated_args
def instantiate_return_type(
return_type: parser.ReturnType,
template_typenames: Sequence[parser.template.Typename],
instantiations: Sequence[parser.Typename],
cpp_typename: parser.Typename,
instantiated_class: 'InstantiatedClass' = None):
"""Instantiate the return type."""
new_type1 = instantiate_type(return_type.type1,
template_typenames,
instantiations,
cpp_typename,
instantiated_class=instantiated_class)
if return_type.type2:
new_type2 = instantiate_type(return_type.type2,
template_typenames,
instantiations,
cpp_typename,
instantiated_class=instantiated_class)
else:
new_type2 = ''
return parser.ReturnType(new_type1, new_type2)
def instantiate_name(original_name: str,
instantiations: Sequence[parser.Typename]):
"""
Concatenate instantiated types with `original_name` to form a new
instantiated name.
NOTE: To avoid conflicts, we should include the instantiation's
namespaces, but that is too verbose.
"""
instantiated_names = []
for inst in instantiations:
# Ensure the first character of the type is capitalized
name = inst.instantiated_name()
# Using `capitalize` on the complete name causes other caps to be lower case
instantiated_names.append(name.replace(name[0], name[0].capitalize()))
return "{}{}".format(original_name, "".join(instantiated_names))
class InstantiationHelper:
"""
Helper class for instantiation templates.
Requires that `instantiation_type` defines a class method called
`construct` to generate the appropriate object type.
Signature for `construct` should be
```
construct(method,
typenames,
class_instantiations,
method_instantiations,
instantiated_args,
parent=parent)
```
"""
def __init__(self, instantiation_type: InstantiatedMembers):
self.instantiation_type = instantiation_type
def instantiate(self, instantiated_methods: List[InstantiatedMembers],
method: ClassMembers, typenames: Sequence[str],
class_instantiations: Sequence[parser.Typename],
method_instantiations: Sequence[parser.Typename],
parent: 'InstantiatedClass'):
"""
Instantiate both the class and method level templates.
"""
instantiations = class_instantiations + method_instantiations
instantiated_args = instantiate_args_list(method.args.list(),
typenames, instantiations,
parent.cpp_typename())
instantiated_methods.append(
self.instantiation_type.construct(method,
typenames,
class_instantiations,
method_instantiations,
instantiated_args,
parent=parent))
return instantiated_methods
def multilevel_instantiation(self, methods_list: Sequence[ClassMembers],
typenames: Sequence[str],
parent: 'InstantiatedClass'):
"""
Helper to instantiate methods at both the class and method level.
Args:
methods_list: The list of methods in the class to instantiated.
typenames: List of class level template parameters, e.g. ['T'].
parent: The instantiated class to which `methods_list` belongs.
"""
instantiated_methods = []
for method in methods_list:
# We creare a copy since we will modify the typenames list.
method_typenames = deepcopy(typenames)
if isinstance(method.template, parser.template.Template):
method_typenames.extend(method.template.typenames)
# Get all combinations of template args
for instantiations in itertools.product(
*method.template.instantiations):
instantiated_methods = self.instantiate(
instantiated_methods,
method,
typenames=method_typenames,
class_instantiations=parent.instantiations,
method_instantiations=list(instantiations),
parent=parent)
else:
# If no constructor level templates, just use the class templates
instantiated_methods = self.instantiate(
instantiated_methods,
method,
typenames=method_typenames,
class_instantiations=parent.instantiations,
method_instantiations=[],
parent=parent)
return instantiated_methods