Optional Arguments

gtwrap/interface_parser/function.py

@@ -15,8 +15,8 @@
 from pyparsing import Optional, ParseResults, delimitedList
 
 from .template import Template
-from .tokens import (COMMA, IDENT, LOPBRACK, LPAREN, PAIR, ROPBRACK, RPAREN,
-                     SEMI_COLON)
+from .tokens import (COMMA, DEFAULT_ARG, EQUAL, IDENT, LOPBRACK, LPAREN, PAIR,
+                     ROPBRACK, RPAREN, SEMI_COLON)
 from .type import TemplatedType, Type
 
 
@@ -29,15 +29,29 @@ class Argument:
     void sayHello(/*`s` is the method argument with type `const string&`*/ const string& s);
     ```
     """
-    rule = ((Type.rule ^ TemplatedType.rule)("ctype") +
-            IDENT("name")).setParseAction(lambda t: Argument(t.ctype, t.name))
+    rule = ((Type.rule ^ TemplatedType.rule)("ctype") + IDENT("name") + \
+            Optional(EQUAL + (DEFAULT_ARG ^ Type.rule ^ TemplatedType.rule) + \
+                Optional(LPAREN + RPAREN)  # Needed to parse the parens for default constructors
+                )("default")
+            ).setParseAction(lambda t: Argument(t.ctype, t.name, t.default))
 
-    def __init__(self, ctype: Union[Type, TemplatedType], name: str):
+    def __init__(self,
+                 ctype: Union[Type, TemplatedType],
+                 name: str,
+                 default: ParseResults = None):
         if isinstance(ctype, Iterable):
             self.ctype = ctype[0]
         else:
             self.ctype = ctype
         self.name = name
+        # If the length is 1, it's a regular type,
+        if len(default) == 1:
+            default = default[0]
+        # This means a tuple has been passed so we convert accordingly
+        elif len(default) > 1:
+            default = tuple(default.asList())
+        self.default = default
+
         self.parent: Union[ArgumentList, None] = None
 
     def __repr__(self) -> str:

gtwrap/interface_parser/tokens.py

@@ -10,7 +10,9 @@
 Author: Duy Nguyen Ta, Fan Jiang, Matthew Sklar, Varun Agrawal, and Frank Dellaert
 """
 
-from pyparsing import Keyword, Literal, Suppress, Word, alphanums, alphas, nums, Or
+from pyparsing import (Keyword, Literal, Or, QuotedString, Suppress, Word,
+                       alphanums, alphas, delimitedList, nums,
+                       pyparsing_common)
 
 # rule for identifiers (e.g. variable names)
 IDENT = Word(alphas + '_', alphanums + '_') ^ Word(nums)
@@ -19,6 +21,18 @@
 
 LPAREN, RPAREN, LBRACE, RBRACE, COLON, SEMI_COLON = map(Suppress, "(){}:;")
 LOPBRACK, ROPBRACK, COMMA, EQUAL = map(Suppress, "<>,=")
+
+# Encapsulating type for numbers, and single and double quoted strings.
+# The pyparsing_common utilities ensure correct coversion to the corresponding type.
+# E.g. pyparsing_common.number will convert 3.1415 to a float type.
+NUMBER_OR_STRING = (pyparsing_common.number ^ QuotedString('"') ^ QuotedString("'"))
+
+# A python tuple, e.g. (1, 9, "random", 3.1415)
+TUPLE = (LPAREN + delimitedList(NUMBER_OR_STRING) + RPAREN)
+
+# Default argument passed to functions/methods.
+DEFAULT_ARG = (NUMBER_OR_STRING ^ pyparsing_common.identifier ^ TUPLE)
+
 CONST, VIRTUAL, CLASS, STATIC, PAIR, TEMPLATE, TYPEDEF, INCLUDE = map(
     Keyword,
     [

gtwrap/interface_parser/type.py

@@ -203,9 +203,12 @@ def from_parse_result(t: ParseResults):
             raise ValueError("Parse result is not a Type")
 
     def __repr__(self) -> str:
-        return "{self.is_const} {self.typename} " \
-            "{self.is_shared_ptr}{self.is_ptr}{self.is_ref}".format(
-            self=self)
+        is_ptr_or_ref = "{0}{1}{2}".format(self.is_shared_ptr, self.is_ptr,
+                                           self.is_ref)
+        return "{is_const}{self.typename}{is_ptr_or_ref}".format(
+            self=self,
+            is_const="const " if self.is_const else "",
+            is_ptr_or_ref=" " + is_ptr_or_ref if is_ptr_or_ref else "")
 
     def to_cpp(self, use_boost: bool) -> str:
         """

gtwrap/pybind_wrapper.py

@@ -45,7 +45,14 @@ def _py_args_names(self, args_list):
         """Set the argument names in Pybind11 format."""
         names = args_list.args_names()
         if names:
-            py_args = ['py::arg("{}")'.format(name) for name in names]
+            py_args = []
+            for arg in args_list.args_list:
+                if arg.default and isinstance(arg.default, str):
+                    arg.default = "\"{arg.default}\"".format(arg=arg)
+                argument = 'py::arg("{name}"){default}'.format(
+                    name=arg.name,
+                    default=' = {0}'.format(arg.default) if arg.default else '')
+                py_args.append(argument)
             return ", " + ", ".join(py_args)
         else:
             return ''
@@ -124,35 +131,29 @@ def _wrap_method(self, method, cpp_class, prefix, suffix, method_suffix=""):
                    suffix=suffix,
                ))
 
+        # Create __repr__ override
+        # We allow all arguments to .print() and let the compiler handle type mismatches.
         if method.name == 'print':
             # Redirect stdout - see pybind docs for why this is a good idea:
             # https://pybind11.readthedocs.io/en/stable/advanced/pycpp/utilities.html#capturing-standard-output-from-ostream
-            ret = ret.replace('self->', 'py::scoped_ostream_redirect output; self->')
+            ret = ret.replace('self->print', 'py::scoped_ostream_redirect output; self->print')
 
-            # __repr__() uses print's implementation:
-            type_list = method.args.to_cpp(self.use_boost)
-            if len(type_list) > 0 and type_list[0].strip() == 'string':
-                ret += '''{prefix}.def("__repr__",
-                    [](const {cpp_class} &a) {{
+            # Make __repr__() call print() internally
+            ret += '''{prefix}.def("__repr__",
+                    [](const {cpp_class}& self{opt_comma}{args_signature_with_names}){{
                         gtsam::RedirectCout redirect;
-                        a.print("");
+                        self.{method_name}({method_args});
                         return redirect.str();
-                    }}){suffix}'''.format(
-                    prefix=prefix,
-                    cpp_class=cpp_class,
-                    suffix=suffix,
-                )
-            else:
-                ret += '''{prefix}.def("__repr__",
-                    [](const {cpp_class} &a) {{
-                        gtsam::RedirectCout redirect;
-                        a.print();
-                        return redirect.str();
-                    }}){suffix}'''.format(
-                    prefix=prefix,
-                    cpp_class=cpp_class,
-                    suffix=suffix,
-                )
+                    }}{py_args_names}){suffix}'''.format(
+                prefix=prefix,
+                cpp_class=cpp_class,
+                opt_comma=', ' if args_names else '',
+                args_signature_with_names=args_signature_with_names,
+                method_name=method.name,
+                method_args=", ".join(args_names) if args_names else '',
+                py_args_names=py_args_names,
+                suffix=suffix)
+
         return ret
 
     def wrap_methods(self, methods, cpp_class, prefix='\n' + ' ' * 8, suffix=''):

gtwrap/template_instantiator.py

@@ -95,8 +95,10 @@ def instantiate_args_list(args_list, template_typenames, instantiations,
     for arg in args_list:
         new_type = instantiate_type(arg.ctype, template_typenames,
                                     instantiations, cpp_typename)
+        default = [arg.default] if isinstance(arg, parser.Argument) else ''
         instantiated_args.append(parser.Argument(name=arg.name,
-                                                 ctype=new_type))
+                                                 ctype=new_type,
+                                                 default=default))
     return instantiated_args
 
 

tests/expected/matlab/MyFactorPosePoint2.m

@@ -4,6 +4,9 @@
 %-------Constructors-------
 %MyFactorPosePoint2(size_t key1, size_t key2, double measured, Base noiseModel)
 %
+%-------Methods-------
+%print(string s, KeyFormatter keyFormatter) : returns void
+%
 classdef MyFactorPosePoint2 < handle
   properties
     ptr_MyFactorPosePoint2 = 0
@@ -29,6 +32,16 @@ function delete(obj)
     %DISPLAY Calls print on the object
     function disp(obj), obj.display; end
     %DISP Calls print on the object
+    function varargout = print(this, varargin)
+      % PRINT usage: print(string s, KeyFormatter keyFormatter) : returns void
+      % Doxygen can be found at https://gtsam.org/doxygen/
+      if length(varargin) == 2 && isa(varargin{1},'char') && isa(varargin{2},'gtsam.KeyFormatter')
+        class_wrapper(55, this, varargin{:});
+        return
+      end
+      error('Arguments do not match any overload of function MyFactorPosePoint2.print');
+    end
+
   end
 
   methods(Static = true)

tests/expected/matlab/TemplatedFunctionRot3.m

@@ -1,6 +1,6 @@
 function varargout = TemplatedFunctionRot3(varargin)
       if length(varargin) == 1 && isa(varargin{1},'gtsam.Rot3')
-        functions_wrapper(8, varargin{:});
+        functions_wrapper(11, varargin{:});
       else
         error('Arguments do not match any overload of function TemplatedFunctionRot3');
       end

tests/expected/matlab/class_wrapper.cpp

@@ -661,6 +661,15 @@ void MyFactorPosePoint2_deconstructor_54(int nargout, mxArray *out[], int nargin
   }
 }
 
+void MyFactorPosePoint2_print_55(int nargout, mxArray *out[], int nargin, const mxArray *in[])
+{
+  checkArguments("print",nargout,nargin-1,2);
+  auto obj = unwrap_shared_ptr<MyFactor<gtsam::Pose2, gtsam::Matrix>>(in[0], "ptr_MyFactorPosePoint2");
+  string& s = *unwrap_shared_ptr< string >(in[1], "ptr_string");
+  gtsam::KeyFormatter& keyFormatter = *unwrap_shared_ptr< gtsam::KeyFormatter >(in[2], "ptr_gtsamKeyFormatter");
+  obj->print(s,keyFormatter);
+}
+
 
 void mexFunction(int nargout, mxArray *out[], int nargin, const mxArray *in[])
 {
@@ -838,6 +847,9 @@ void mexFunction(int nargout, mxArray *out[], int nargin, const mxArray *in[])
     case 54:
       MyFactorPosePoint2_deconstructor_54(nargout, out, nargin-1, in+1);
       break;
+    case 55:
+      MyFactorPosePoint2_print_55(nargout, out, nargin-1, in+1);
+      break;
     }
   } catch(const std::exception& e) {
     mexErrMsgTxt(("Exception from gtsam:\n" + std::string(e.what()) + "\n").c_str());

tests/expected/matlab/functions_wrapper.cpp

@@ -196,7 +196,25 @@ void MultiTemplatedFunctionDoubleSize_tDouble_7(int nargout, mxArray *out[], int
   size_t y = unwrap< size_t >(in[1]);
   out[0] = wrap< double >(MultiTemplatedFunctionDoubleSize_tDouble(x,y));
 }
-void TemplatedFunctionRot3_8(int nargout, mxArray *out[], int nargin, const mxArray *in[])
+void DefaultFuncInt_8(int nargout, mxArray *out[], int nargin, const mxArray *in[])
+{
+  checkArguments("DefaultFuncInt",nargout,nargin,1);
+  int a = unwrap< int >(in[0]);
+  DefaultFuncInt(a);
+}
+void DefaultFuncString_9(int nargout, mxArray *out[], int nargin, const mxArray *in[])
+{
+  checkArguments("DefaultFuncString",nargout,nargin,1);
+  string& s = *unwrap_shared_ptr< string >(in[0], "ptr_string");
+  DefaultFuncString(s);
+}
+void DefaultFuncObj_10(int nargout, mxArray *out[], int nargin, const mxArray *in[])
+{
+  checkArguments("DefaultFuncObj",nargout,nargin,1);
+  gtsam::KeyFormatter& keyFormatter = *unwrap_shared_ptr< gtsam::KeyFormatter >(in[0], "ptr_gtsamKeyFormatter");
+  DefaultFuncObj(keyFormatter);
+}
+void TemplatedFunctionRot3_11(int nargout, mxArray *out[], int nargin, const mxArray *in[])
 {
   checkArguments("TemplatedFunctionRot3",nargout,nargin,1);
   gtsam::Rot3& t = *unwrap_shared_ptr< gtsam::Rot3 >(in[0], "ptr_gtsamRot3");
@@ -239,7 +257,16 @@ void mexFunction(int nargout, mxArray *out[], int nargin, const mxArray *in[])
       MultiTemplatedFunctionDoubleSize_tDouble_7(nargout, out, nargin-1, in+1);
       break;
     case 8:
-      TemplatedFunctionRot3_8(nargout, out, nargin-1, in+1);
+      DefaultFuncInt_8(nargout, out, nargin-1, in+1);
+      break;
+    case 9:
+      DefaultFuncString_9(nargout, out, nargin-1, in+1);
+      break;
+    case 10:
+      DefaultFuncObj_10(nargout, out, nargin-1, in+1);
+      break;
+    case 11:
+      TemplatedFunctionRot3_11(nargout, out, nargin-1, in+1);
       break;
     }
   } catch(const std::exception& e) {

tests/expected/python/class_pybind.cpp

@@ -57,9 +57,9 @@ PYBIND11_MODULE(class_py, m_) {
         .def("return_ptrs",[](Test* self, std::shared_ptr<Test> p1, std::shared_ptr<Test> p2){return self->return_ptrs(p1, p2);}, py::arg("p1"), py::arg("p2"))
         .def("print_",[](Test* self){ py::scoped_ostream_redirect output; self->print();})
         .def("__repr__",
-                    [](const Test &a) {
+                    [](const Test& self){
                         gtsam::RedirectCout redirect;
-                        a.print();
+                        self.print();
                         return redirect.str();
                     })
         .def("set_container",[](Test* self, std::vector<testing::Test> container){ self->set_container(container);}, py::arg("container"))
@@ -83,7 +83,14 @@ PYBIND11_MODULE(class_py, m_) {
     py::class_<MultipleTemplates<int, float>, std::shared_ptr<MultipleTemplates<int, float>>>(m_, "MultipleTemplatesIntFloat");
 
     py::class_<MyFactor<gtsam::Pose2, gtsam::Matrix>, std::shared_ptr<MyFactor<gtsam::Pose2, gtsam::Matrix>>>(m_, "MyFactorPosePoint2")
-        .def(py::init<size_t, size_t, double, const std::shared_ptr<gtsam::noiseModel::Base>>(), py::arg("key1"), py::arg("key2"), py::arg("measured"), py::arg("noiseModel"));
+        .def(py::init<size_t, size_t, double, const std::shared_ptr<gtsam::noiseModel::Base>>(), py::arg("key1"), py::arg("key2"), py::arg("measured"), py::arg("noiseModel"))
+        .def("print_",[](MyFactor<gtsam::Pose2, gtsam::Matrix>* self, const string& s, const gtsam::KeyFormatter& keyFormatter){ py::scoped_ostream_redirect output; self->print(s, keyFormatter);}, py::arg("s") = "factor: ", py::arg("keyFormatter") = gtsam::DefaultKeyFormatter)
+        .def("__repr__",
+                    [](const MyFactor<gtsam::Pose2, gtsam::Matrix>& self, const string& s, const gtsam::KeyFormatter& keyFormatter){
+                        gtsam::RedirectCout redirect;
+                        self.print(s, keyFormatter);
+                        return redirect.str();
+                    }, py::arg("s") = "factor: ", py::arg("keyFormatter") = gtsam::DefaultKeyFormatter);
 
 
 #include "python/specializations.h"

tests/expected/python/functions_pybind.cpp

@@ -30,6 +30,9 @@ PYBIND11_MODULE(functions_py, m_) {
     m_.def("overloadedGlobalFunction",[](int a, double b){return ::overloadedGlobalFunction(a, b);}, py::arg("a"), py::arg("b"));
     m_.def("MultiTemplatedFunctionStringSize_tDouble",[](const T& x, size_t y){return ::MultiTemplatedFunction<string,size_t,double>(x, y);}, py::arg("x"), py::arg("y"));
     m_.def("MultiTemplatedFunctionDoubleSize_tDouble",[](const T& x, size_t y){return ::MultiTemplatedFunction<double,size_t,double>(x, y);}, py::arg("x"), py::arg("y"));
+    m_.def("DefaultFuncInt",[](int a){ ::DefaultFuncInt(a);}, py::arg("a") = 123);
+    m_.def("DefaultFuncString",[](const string& s){ ::DefaultFuncString(s);}, py::arg("s") = "hello");
+    m_.def("DefaultFuncObj",[](const gtsam::KeyFormatter& keyFormatter){ ::DefaultFuncObj(keyFormatter);}, py::arg("keyFormatter") = gtsam::DefaultKeyFormatter);
     m_.def("TemplatedFunctionRot3",[](const gtsam::Rot3& t){ ::TemplatedFunction<Rot3>(t);}, py::arg("t"));
 
 #include "python/specializations.h"

tests/fixtures/class.i

@@ -79,6 +79,8 @@ virtual class ns::OtherClass;
 template<POSE, POINT>
 class MyFactor {
   MyFactor(size_t key1, size_t key2, double measured, const gtsam::noiseModel::Base* noiseModel);
+  void print(const string &s = "factor: ",
+             const gtsam::KeyFormatter &keyFormatter = gtsam::DefaultKeyFormatter);
 };
 
 // and a typedef specializing it

tests/fixtures/functions.i

@@ -26,3 +26,8 @@ template<T>
 void TemplatedFunction(const T& t);
 
 typedef TemplatedFunction<gtsam::Rot3> TemplatedFunctionRot3;
+
+// Check default arguments
+void DefaultFuncInt(int a = 123);
+void DefaultFuncString(const string& s = "hello");
+void DefaultFuncObj(const gtsam::KeyFormatter& keyFormatter = gtsam::DefaultKeyFormatter);

tests/test_interface_parser.py

@@ -179,6 +179,33 @@ def test_argument_list_templated(self):
         self.assertEqual("vector<boost::shared_ptr<T>>",
                          args_list[1].ctype.to_cpp(True))
 
+    def test_default_arguments(self):
+        """Tests any expression that is a valid default argument"""
+        args = ArgumentList.rule.parseString(
+            "string s=\"hello\", int a=3, "
+            "int b, double pi = 3.1415, "
+            "gtsam::KeyFormatter kf = gtsam::DefaultKeyFormatter, "
+            "std::vector<size_t> p = std::vector<size_t>(), "
+            "std::vector<size_t> l = (1, 2, 'name', \"random\", 3.1415)"
+        )[0].args_list
+
+        # Test for basic types
+        self.assertEqual(args[0].default, "hello")
+        self.assertEqual(args[1].default, 3)
+        # '' is falsy so we can check against it
+        self.assertEqual(args[2].default, '')
+        self.assertFalse(args[2].default)
+
+        self.assertEqual(args[3].default, 3.1415)
+
+        # Test non-basic type
+        self.assertEqual(repr(args[4].default.typename), 'gtsam::DefaultKeyFormatter')
+        # Test templated type
+        self.assertEqual(repr(args[5].default.typename), 'std::vector<size_t>')
+        # Test for allowing list as default argument
+        print(args)
+        self.assertEqual(args[6].default, (1, 2, 'name', "random", 3.1415))
+
     def test_return_type(self):
         """Test ReturnType"""
         # Test void
@@ -481,6 +508,5 @@ class Global{
         self.assertEqual(["two", "two_dummy", "two"],
                          [x.name for x in module.content[0].content])
 
-
 if __name__ == '__main__':
     unittest.main()