added gopy:interface=handle doc directive to interpret interface{} args as handles instead of strings; fix go.nil to be a variable not a class; uncomment RemoveAll for main_test work dir; remove more stuff from maps test out to enable consistency; add tests for go.nil, new interface functionality.

Author: Randall C. O'Reilly

_examples/funcs/funcs.go

@@ -31,6 +31,14 @@ func (fs *FunStruct) OtherMeth(arg1 int, args string) {
 	fmt.Printf("arg1: %d args: %s\n", arg1, args)
 }
 
+func (fs *FunStruct) ObjArg(ofs *FunStruct) {
+	if ofs == nil {
+		fmt.Printf("got nil\n")
+	} else {
+		fmt.Printf("ofs FieldI: %d FieldS: %s\n", ofs.FieldI, ofs.FieldS)
+	}
+}
+
 var (
 	F1 func()
 	F2 Func

_examples/funcs/test.py

@@ -47,6 +47,13 @@ def CallSelf(self):
 print("cls.CallSelf...")
 cls.CallSelf()
 
+
+print("fs.ObjArg with nil")
+fs.ObjArg(go.nil)
+
+print("fs.ObjArg with fs")
+fs.ObjArg(fs)
+
 # todo: not currently supported:
 
 # print("funcs.F1()...")

_examples/iface/iface.go

@@ -15,7 +15,10 @@ type Iface interface {
 }
 
 // T implements Iface
-type T struct{}
+type T struct {
+	FldI int
+	FldS string
+}
 
 func (t *T) F() {
 	cpkg.Printf("t.F [CALLED]\n")
@@ -27,3 +30,13 @@ func CallIface(v Iface) {
 	v.F()
 	cpkg.Printf("iface.CallIface... [DONE]\n")
 }
+
+// by default, interface{} is converted to string (most universal type)
+func IfaceString(str interface{}) {
+	cpkg.Printf("iface as string: %v\n", str)
+}
+
+//gopy:interface=handle this magic directive says, treat it as a handle
+func IfaceHandle(ifc interface{}) {
+	cpkg.Printf("iface as handle: %v\n", ifc)
+}

_examples/iface/test.py

@@ -5,7 +5,7 @@
 ## py2/py3 compat
 from __future__ import print_function
 
-import iface
+import iface, go
 
 ### test docs
 print("doc(iface): %r" % (iface.__doc__,))
@@ -18,4 +18,16 @@
 print("iface.CallIface(t)")
 iface.CallIface(t)
 
+print('iface.IfaceString("test string"')
+iface.IfaceString("test string")
+
+print('iface.IfaceString(str(42))')
+iface.IfaceString(str(42))
+
+print('iface.IfaceHandle(t)')
+iface.IfaceHandle(t)
+
+print('iface.IfaceHandle(go.nil)')
+iface.IfaceHandle(go.nil)
+
 print("OK")

_examples/maps/test.py

@@ -8,9 +8,6 @@
 a = maps.New()
 b = {1: 3.0, 2: 5.0}
 
-print('map a:', a)
-print('map a repr:', a.__repr__())
-
 # set to true to test all the builtin map functionality
 # due to the random nature of map access in Go, this will
 # cause go test to fail randomly so it is off by default
@@ -19,6 +16,9 @@
 testall = False
 
 if testall:
+    print('map a:', a)
+    print('map a repr:', a.__repr__())
+
     print('map a keys:', a.keys())
     print('map a values:', a.values())
     print('map a items:', a.items())

bind/gen.go

@@ -230,13 +230,12 @@ import collections
 	
 class GoClass(object):
 	"""GoClass is the base class for all GoPy wrapper classes"""
-	pass
-	
-class nil(GoClass):
-	"""nil is the nil pointer in Go"""
 	def __init__(self):
 		self.handle = 0
-		
+
+# use go.nil for nil pointers 
+nil = GoClass()
+
 def Init():
 	"""calls the GoPyInit function, which runs the 'main' code string that was passed using -main arg to gopy"""
 	_%[1]s.GoPyInit()

bind/gen_func.go

@@ -19,10 +19,11 @@ func (g *pyGen) genFuncSig(sym *symbol, fsym *Func) bool {
 		return false
 	}
 
-	gname, _, err := extractPythonName(fsym.GoName(), fsym.Doc())
+	gname, gdoc, err := extractPythonName(fsym.GoName(), fsym.Doc())
 	if err != nil {
 		return false
 	}
+	ifchandle, gdoc := isIfaceHandle(gdoc)
 
 	sig := fsym.sig
 	args := sig.Params()
@@ -55,11 +56,16 @@ func (g *pyGen) genFuncSig(sym *symbol, fsym *Func) bool {
 			return false
 		}
 		anm := pySafeArg(arg.Name(), i)
-		goArgs = append(goArgs, fmt.Sprintf("%s %s", anm, sarg.cgoname))
-		if sarg.cpyname == "PyObject*" {
-			pyArgs = append(pyArgs, fmt.Sprintf("param('%s', '%s', transfer_ownership=False)", sarg.cpyname, anm))
+		if ifchandle && arg.sym.goname == "interface{}" {
+			goArgs = append(goArgs, fmt.Sprintf("%s %s", anm, CGoHandle))
+			pyArgs = append(pyArgs, fmt.Sprintf("param('%s', '%s')", PyHandle, anm))
 		} else {
-			pyArgs = append(pyArgs, fmt.Sprintf("param('%s', '%s')", sarg.cpyname, anm))
+			goArgs = append(goArgs, fmt.Sprintf("%s %s", anm, sarg.cgoname))
+			if sarg.cpyname == "PyObject*" {
+				pyArgs = append(pyArgs, fmt.Sprintf("param('%s', '%s', transfer_ownership=False)", sarg.cpyname, anm))
+			} else {
+				pyArgs = append(pyArgs, fmt.Sprintf("param('%s', '%s')", sarg.cpyname, anm))
+			}
 		}
 		wpArgs = append(wpArgs, anm)
 	}
@@ -138,6 +144,15 @@ func (g *pyGen) genMethod(s *symbol, o *Func) {
 	}
 }
 
+func isIfaceHandle(gdoc string) (bool, string) {
+	const PythonIface = "\ngopy:interface=handle"
+	if idx := strings.Index(gdoc, PythonIface); idx > 0 {
+		gdoc = gdoc[:idx] + gdoc[idx+len(PythonIface)+1:]
+		return true, gdoc
+	}
+	return false, gdoc
+}
+
 func (g *pyGen) genFuncBody(sym *symbol, fsym *Func) {
 	isMethod := (sym != nil)
 	isIface := false
@@ -153,6 +168,7 @@ func (g *pyGen) genFuncBody(sym *symbol, fsym *Func) {
 	pkgname := g.outname
 
 	_, gdoc, _ := extractPythonName(fsym.GoName(), fsym.Doc())
+	ifchandle, gdoc := isIfaceHandle(gdoc)
 
 	sig := fsym.Signature()
 	res := sig.Results()
@@ -233,7 +249,9 @@ if err != nil {
 	for i, arg := range args {
 		na := ""
 		anm := pySafeArg(arg.Name(), i)
-		if arg.sym.isSignature() {
+		if ifchandle && arg.sym.goname == "interface{}" {
+			na = fmt.Sprintf(`gopyh.VarFmHandle((gopyh.CGoHandle)(%s), "interface{}")`, anm)
+		} else if arg.sym.isSignature() {
 			na = fmt.Sprintf("%s", arg.sym.py2go)
 		} else {
 			if arg.sym.py2go != "" {
@@ -243,7 +261,13 @@ if err != nil {
 			}
 		}
 		callArgs = append(callArgs, na)
-		if arg.sym.hasHandle() {
+		if arg.sym.goname == "interface{}" {
+			if ifchandle {
+				wrapArgs = append(wrapArgs, fmt.Sprintf("%s.handle", anm))
+			} else {
+				wrapArgs = append(wrapArgs, anm)
+			}
+		} else if arg.sym.hasHandle() {
 			wrapArgs = append(wrapArgs, fmt.Sprintf("%s.handle", anm))
 		} else {
 			wrapArgs = append(wrapArgs, anm)

bind/gen_map.go

@@ -72,7 +72,7 @@ func (g *pyGen) genMapInit(slc *symbol, extTypes, pyWrapOnly bool, mpob *Map) {
 	keyslt := types.NewSlice(typ.Key())
 	keyslsym := current.symtype(keyslt)
 	if keyslsym == nil {
-		fmt.Printf("nil key slice type!: %n  map: %v\n", current.fullTypeString(keyslt), slc.goname)
+		fmt.Printf("nil key slice type!: %s map: %s\n", current.fullTypeString(keyslt), slc.goname)
 		return
 	}
 	keyslnm := ""

bind/symbols.go

@@ -106,9 +106,6 @@ func isPyCompatVar(v *symbol) error {
 	if isErrorType(v.gotyp) {
 		return fmt.Errorf("gopy: var is error type")
 	}
-	// if v.gotyp.String() == "interface{}" {
-	// 	return fmt.Errorf("gopy: var is interface{}")
-	// }
 	if _, isChan := v.gotyp.(*types.Chan); isChan {
 		return fmt.Errorf("gopy: var is channel type")
 	}
@@ -129,9 +126,6 @@ func isPyCompatType(typ types.Type) error {
 	if _, isChan := typ.(*types.Chan); isChan {
 		return fmt.Errorf("gopy: type is channel type")
 	}
-	// if typ.String() == "interface{}" {
-	// 	return fmt.Errorf("gopy: type is interface{}")
-	// }
 	return nil
 }
 

main_test.go

@@ -232,14 +232,18 @@ func TestBindFuncs(t *testing.T) {
 	testPkg(t, pkg{
 		path: path,
 		lang: features[path],
-		want: []byte(`fs.CallBack(22, cbfun)...
+		want: []byte(`got nil
+ofs FieldI: 42 FieldS: str field
+fs.CallBack(22, cbfun)...
 in python cbfun: FieldI:  42  FieldS:  str field  ival:  22  sval:  str field
 fs.CallBackIf(22, cbfun)...
 in python cbfunif: FieldI:  42  FieldS:  str field  ival:  22  ifval:  str field
 fs.CallBack(32, cls.ClassFun)...
 in python class fun: FieldI:  42  FieldS:  str field  ival:  32  sval:  str field
 cls.CallSelf...
 in python class fun: FieldI:  42  FieldS:  str field  ival:  77  sval:  str field
+fs.ObjArg with nil
+fs.ObjArg with fs
 OK
 `),
 	})
@@ -436,10 +440,18 @@ func TestBindInterfaces(t *testing.T) {
 iface.CallIface...
 t.F [CALLED]
 iface.CallIface... [DONE]
+iface as string: test string
+iface as string: 42
+iface as handle: &{0 }
+iface as handle: <nil>
 doc(iface): '\npackage iface tests various aspects of interfaces.\n\n'
 t = iface.T()
 t.F()
 iface.CallIface(t)
+iface.IfaceString("test string"
+iface.IfaceString(str(42))
+iface.IfaceHandle(t)
+iface.IfaceHandle(go.nil)
 OK
 `),
 	})
@@ -509,18 +521,15 @@ func TestBuiltinMaps(t *testing.T) {
 	testPkg(t, pkg{
 		path: path,
 		lang: features[path],
-		want: []byte(`map a: maps.Map_int_float64 len: 2 handle: 1 {1=3.0, 2=5.0, }
-map a repr: maps.Map_int_float64({1=3.0, 2=5.0, })
-map a[1]: 3.0
+		want: []byte(`map a[1]: 3.0
 map a[2]: 5.0
-caught error: <built-in function Map_int_float64_elem> returned a result with an error set
 maps.Sum from Go map: 8.0
 map b: {1: 3.0, 2: 5.0}
 maps.Sum from Python dictionary: 8.0
-maps.Keys from Go map: go.Slice_int len: 2 handle: 5 [1, 2]
-maps.Values from Go map: go.Slice_float64 len: 2 handle: 6 [3.0, 5.0]
-maps.Keys from Python dictionary: go.Slice_int len: 2 handle: 8 [1, 2]
-maps.Values from Python dictionary: go.Slice_float64 len: 2 handle: 10 [3.0, 5.0]
+maps.Keys from Go map: go.Slice_int len: 2 handle: 3 [1, 2]
+maps.Values from Go map: go.Slice_float64 len: 2 handle: 4 [3.0, 5.0]
+maps.Keys from Python dictionary: go.Slice_int len: 2 handle: 6 [1, 2]
+maps.Values from Python dictionary: go.Slice_float64 len: 2 handle: 8 [3.0, 5.0]
 deleted 1 from a: maps.Map_int_float64 len: 1 handle: 1 {2=5.0, }
 OK
 `),
@@ -696,7 +705,7 @@ func testPkgBackend(t *testing.T, pyvm string, table pkg) {
 	if err != nil {
 		t.Fatalf("[%s:%s]: could not create workdir: %v\n", pyvm, table.path, err)
 	}
-	// defer os.RemoveAll(workdir)
+	defer os.RemoveAll(workdir)
 	defer bind.ResetPackages()
 
 	// fmt.Printf("building in work dir: %s\n", workdir)