Merge 364ff89 into 390aa2b

main.go

@@ -150,7 +150,7 @@ func InjectPry(filePath string) (string, error) {
 }
 
 // GenerateFile generates and executes a temp file with the given imports
-func GenerateFile(imports []string) error {
+func GenerateFile(imports []string, extraStatements string) error {
 	dir, err := ioutil.TempDir("", "pry")
 	if err != nil {
 		return err
@@ -159,7 +159,7 @@ func GenerateFile(imports []string) error {
 	for _, imp := range imports {
 		file += fmt.Sprintf("\t%#v\n", imp)
 	}
-	file += ")\nfunc main() {\n\tpry.Pry()\n}"
+	file += ")\nfunc main() {\n\t" + extraStatements + "\n\tpry.Pry()\n}\n"
 
 	newPath := dir + "/main.go"
 	ioutil.WriteFile(newPath, []byte(file), 0644)
@@ -186,6 +186,7 @@ func main() {
 	// FLAGS
 	imports := flag.String("i", "fmt,math", "packages to import, comma seperated")
 	revert := flag.Bool("r", true, "whether to revert changes on exit")
+	execute := flag.String("e", "", "statements to execute")
 	flag.BoolVar(&debug, "d", false, "display debug statements")
 
 	flag.CommandLine.Usage = func() {
@@ -201,7 +202,7 @@ func main() {
 	flag.Parse()
 	cmdArgs := flag.Args()
 	if len(cmdArgs) == 0 {
-		err := GenerateFile(strings.Split(*imports, ","))
+		err := GenerateFile(strings.Split(*imports, ","), *execute)
 		if err != nil {
 			panic(err)
 		}

pry/helpers.go

@@ -7,78 +7,91 @@ import (
 	"github.com/pkg/errors"
 )
 
+// InterpretError is an error returned by the interpreter and shouldn't be
+// passed to the user or running code.
+type InterpretError struct {
+	err error
+}
+
+func (a *InterpretError) Error() error {
+	if a == nil {
+		return nil
+	}
+	return a.err
+}
+
 // Append is a runtime replacement for the append function
-func Append(arr interface{}, elems ...interface{}) (interface{}, error) {
+func Append(arr interface{}, elems ...interface{}) (interface{}, *InterpretError) {
 	arrVal := reflect.ValueOf(arr)
 	valArr := make([]reflect.Value, len(elems))
 	for i, elem := range elems {
 		if reflect.TypeOf(arr) != reflect.SliceOf(reflect.TypeOf(elem)) {
-			return nil, fmt.Errorf("%T cannot append to %T", elem, arr)
+			return nil, &InterpretError{fmt.Errorf("%T cannot append to %T", elem, arr)}
 		}
 		valArr[i] = reflect.ValueOf(elem)
 	}
 	return reflect.Append(arrVal, valArr...).Interface(), nil
 }
 
 // Make is a runtime replacement for the make function
-func Make(t interface{}, args ...interface{}) (interface{}, error) {
+func Make(t interface{}, args ...interface{}) (interface{}, *InterpretError) {
 	typ, isType := t.(reflect.Type)
 	if !isType {
-		return nil, fmt.Errorf("invalid type %#v", t)
+		return nil, &InterpretError{fmt.Errorf("invalid type %#v", t)}
 	}
 	switch typ.Kind() {
 	case reflect.Slice:
 		if len(args) < 1 || len(args) > 2 {
-			return nil, errors.New("invalid number of arguments. Missing len or extra?")
+			return nil, &InterpretError{errors.New("invalid number of arguments. Missing len or extra?")}
 		}
 		length, isInt := args[0].(int)
 		if !isInt {
-			return nil, errors.New("len is not int")
+			return nil, &InterpretError{errors.New("len is not int")}
 		}
 		capacity := length
 		if len(args) == 2 {
 			capacity, isInt = args[0].(int)
 			if !isInt {
-				return nil, errors.New("len is not int")
+				return nil, &InterpretError{errors.New("len is not int")}
 			}
 		}
 		if length < 0 || capacity < 0 {
-			return nil, errors.Errorf("negative length or capacity")
+			return nil, &InterpretError{errors.Errorf("negative length or capacity")}
 		}
 		slice := reflect.MakeSlice(typ, length, capacity)
 		return slice.Interface(), nil
 
 	case reflect.Chan:
 		if len(args) > 1 {
 			fmt.Printf("CHAN ARGS %#v", args)
-			return nil, errors.New("too many arguments")
+			return nil, &InterpretError{errors.New("too many arguments")}
 		}
 		size := 0
 		if len(args) == 1 {
 			var isInt bool
 			size, isInt = args[0].(int)
 			if !isInt {
-				return nil, errors.New("size is not int")
+				return nil, &InterpretError{errors.New("size is not int")}
 			}
 		}
 		if size < 0 {
-			return nil, errors.Errorf("negative buffer size")
+			return nil, &InterpretError{errors.Errorf("negative buffer size")}
 		}
 		buffer := reflect.MakeChan(typ, size)
 		return buffer.Interface(), nil
 
 	default:
-		return nil, fmt.Errorf("unknown kind type %T", t)
+		return nil, &InterpretError{fmt.Errorf("unknown kind type %T", t)}
 	}
 }
 
 // Close is a runtime replacement for the "close" function.
-func Close(t interface{}) (interface{}, error) {
+func Close(t interface{}) (interface{}, *InterpretError) {
 	reflect.ValueOf(t).Close()
 	return nil, nil
 }
 
 // Len is a runtime replacement for the len function
-func Len(t interface{}) (interface{}, error) {
+func Len(t interface{}) (interface{}, *InterpretError) {
 	return reflect.ValueOf(t).Len(), nil
 }

pry/interpreter.go

@@ -569,12 +569,12 @@ func (scope *Scope) Interpret(expr ast.Node) (interface{}, error) {
 			rhs = rhs[:0]
 
 			for i := 0; i < rhsLen; i++ {
-				rhs[i] = rhsV.Index(i).Interface()
+				rhs = append(rhs, rhsV.Index(i).Interface())
 			}
 		}
 
 		if len(rhs) != len(e.Lhs) {
-			return nil, fmt.Errorf("assignment count mismatch: %d = %d", len(e.Lhs), len(rhs))
+			return nil, fmt.Errorf("assignment count mismatch: %d = %d (%+v)", len(e.Lhs), len(rhs), rhs)
 		}
 
 		for i, id := range e.Lhs {
@@ -1059,13 +1059,21 @@ func (scope *Scope) ExecuteFunc(funExpr ast.Expr, args []interface{}) (interface
 		return nil, errors.Errorf("number of arguments doesn't match function; expected %d; got %+v", funVal.Type().NumIn(), args)
 	}
 	values := ValuesToInterfaces(funVal.Call(valueArgs))
+	if len(values) > 0 {
+		if last, ok := values[len(values)-1].(*InterpretError); ok {
+			values = values[:len(values)-1]
+			if err := last.Error(); err != nil {
+				return nil, err
+			}
+		}
+	}
+
 	if len(values) == 0 {
 		return nil, nil
 	} else if len(values) == 1 {
 		return values[0], nil
 	}
-	err, _ = values[1].(error)
-	return values[0], err
+	return values, nil
 }
 
 // ConfigureTypes configures the scope type checker

pry/interpreter_test.go

@@ -664,6 +664,29 @@ func TestAppend(t *testing.T) {
 	}
 }
 
+func TestMultiReturn(t *testing.T) {
+	t.Parallel()
+
+	scope := NewScope()
+	scope.Set("f", func() (int, error) {
+		return 0, nil
+	})
+
+	_, err := scope.InterpretString(`a, err := f()`)
+	if err != nil {
+		t.Error(err)
+	}
+	expected := 0
+	outV, found := scope.Get("a")
+	if !found {
+		t.Errorf("failed to find \"a\"")
+	}
+	out := outV.(int)
+	if !reflect.DeepEqual(expected, out) {
+		t.Errorf("Expected %#v got %#v.", expected, out)
+	}
+}
+
 func TestDeclareAssignVar(t *testing.T) {
 	t.Parallel()