gencpy: generate and insert function signatures at start of docstring

bind/gencpy.go

@@ -86,7 +86,7 @@ func (g *cpyGen) gen() error {
 
 		case *types.Func:
 			funcs = append(funcs, cpyFunc{typ: obj})
-			docs[obj.Name()] = g.pkg.getDoc(obj)
+			docs[obj.Name()] = g.getPyDoc(obj)
 
 		case *types.TypeName:
 			named := obj.Type().(*types.Named)
@@ -322,7 +322,7 @@ func (g *cpyGen) genStruct(cpy cpyStruct) {
 	g.impl.Printf("0,\t/*tp_setattro*/\n")
 	g.impl.Printf("0,\t/*tp_as_buffer*/\n")
 	g.impl.Printf("Py_TPFLAGS_DEFAULT,\t/*tp_flags*/\n")
-	g.impl.Printf("%q,\t/* tp_doc */\n", g.pkg.getDoc(obj))
+	g.impl.Printf("%q,\t/* tp_doc */\n", g.getPyDoc(obj))
 	g.impl.Printf("0,\t/* tp_traverse */\n")
 	g.impl.Printf("0,\t/* tp_clear */\n")
 	g.impl.Printf("0,\t/* tp_richcompare */\n")
@@ -549,3 +549,46 @@ func (g *cpyGen) genPreamble() {
 	n := g.pkg.pkg.Name()
 	g.decl.Printf(cPreamble, n, g.pkg.pkg.Path(), filepath.Base(n))
 }
+
+func (g *cpyGen) getPyDoc(o types.Object) string {
+	doc := g.pkg.getDoc(o)
+
+	switch o.(type) {
+
+	case *types.Func:
+		sig := o.Type().(*types.Signature)
+
+		parseFn := func(tup *types.Tuple) []string {
+			params := []string{}
+			if tup == nil {
+				return params
+			}
+			for i := 0; i < tup.Len(); i++ {
+				paramVar := tup.At(i)
+				paramType := pyTypeName(paramVar.Type())
+				if paramVar.Name() != "" {
+					paramType = fmt.Sprintf("%s %s", paramType, paramVar.Name())
+				}
+				params = append(params, paramType)
+			}
+			return params
+		}
+
+		params := parseFn(sig.Params())
+		results := parseFn(sig.Results())
+
+		paramString := strings.Join(params, ", ")
+		resultString := strings.Join(results, ", ")
+
+		docSig := fmt.Sprintf("%s(%s) %s", o.Name(), paramString, resultString)
+
+		if doc != "" {
+			doc = fmt.Sprintf("%s\n\n%s", docSig, doc)
+		} else {
+			doc = docSig
+		}
+
+	}
+
+	return doc
+}

bind/types.go

@@ -45,10 +45,23 @@ func cgoTypeName(typ types.Type) string {
 	return typ.String()
 }
 
+func pyTypeName(typ types.Type) string {
+	switch typ := typ.(type) {
+	case *types.Basic:
+		kind := typ.Kind()
+		o, ok := typedescr[kind]
+		if ok {
+			return o.pysig
+		}
+	}
+	return "object"
+}
+
 type typedesc struct {
 	ctype   string
 	cgotype string
 	pyfmt   string
+	pysig   string
 }
 
 var typedescr = map[types.BasicKind]typedesc{
@@ -56,101 +69,118 @@ var typedescr = map[types.BasicKind]typedesc{
 		ctype:   "_Bool",
 		cgotype: "GoBool",
 		pyfmt:   "b",
+		pysig:   "bool",
 	},
 
 	types.Int: typedesc{
 		ctype:   "int",
 		cgotype: "GoInt",
 		pyfmt:   "i",
+		pysig:   "int",
 	},
 
 	types.Int8: typedesc{
 		ctype:   "int8_t",
 		cgotype: "GoInt8",
 		pyfmt:   "c",
+		pysig:   "int",
 	},
 
 	types.Int16: typedesc{
 		ctype:   "int16_t",
 		cgotype: "GoInt16",
 		pyfmt:   "h",
+		pysig:   "int",
 	},
 
 	types.Int32: typedesc{
 		ctype:   "int32_t",
 		cgotype: "GoInt32",
 		pyfmt:   "i",
+		pysig:   "long",
 	},
 
 	types.Int64: typedesc{
 		ctype:   "int64_t",
 		cgotype: "GoInt64",
 		pyfmt:   "k",
+		pysig:   "long",
 	},
 
 	types.Uint: typedesc{
 		ctype:   "unsigned int",
 		cgotype: "GoUint",
 		pyfmt:   "I",
+		pysig:   "int",
 	},
 
 	types.Uint8: typedesc{
 		ctype:   "uint8_t",
 		cgotype: "GoUint8",
 		pyfmt:   "b",
+		pysig:   "int",
 	},
 
 	types.Uint16: typedesc{
 		ctype:   "uint16_t",
 		cgotype: "GoUint16",
 		pyfmt:   "H",
+		pysig:   "int",
 	},
 
 	types.Uint32: typedesc{
 		ctype:   "uint32_t",
 		cgotype: "GoUint32",
 		pyfmt:   "I",
+		pysig:   "long",
 	},
 
 	types.Uint64: typedesc{
 		ctype:   "uint64_t",
 		cgotype: "GoUint64",
 		pyfmt:   "K",
+		pysig:   "long",
 	},
 
 	types.Float32: typedesc{
 		ctype:   "float",
 		cgotype: "float",
 		pyfmt:   "f",
+		pysig:   "float",
 	},
 
 	types.Float64: typedesc{
 		ctype:   "double",
 		cgotype: "double",
 		pyfmt:   "d",
+		pysig:   "float",
 	},
 
 	types.Complex64: typedesc{
 		ctype:   "float complex",
 		cgotype: "GoComplex64",
 		pyfmt:   "D",
+		pysig:   "float",
 	},
 
 	types.Complex128: typedesc{
 		ctype:   "double complex",
 		cgotype: "GoComplex128",
 		pyfmt:   "D",
+		pysig:   "float",
 	},
 
 	types.String: typedesc{
 		ctype:   "const char*",
 		cgotype: "GoString",
 		pyfmt:   "s",
+		pysig:   "str",
 	},
 
 	types.UnsafePointer: typedesc{
 		ctype:   "void*",
 		cgotype: "void*",
 		pyfmt:   "?",
+		pysig:   "object",
 	},
 }