accounts/abi: Modified unpackAtomic to accept struct lvalues

Author: jpeletier

accounts/abi/abi.go

@@ -86,7 +86,7 @@ func (abi ABI) Unpack(v interface{}, name string, output []byte) (err error) {
 		}
 		return method.Outputs.Unpack(v, output)
 	} else if event, ok := abi.Events[name]; ok {
-		return event.Inputs.unpackTuple(v, output)
+		return event.Inputs.Unpack(v, output)
 	}
 	return fmt.Errorf("abi: could not locate named method or event")
 }

accounts/abi/argument.go

@@ -113,16 +113,8 @@ func (arguments Arguments) unpackTuple(v interface{}, marshalledValues []interfa
 	}
 	// If the output interface is a struct, make sure names don't collide
 	if kind == reflect.Struct {
-		exists := make(map[string]bool)
-		for _, arg := range arguments {
-			field := capitalise(arg.Name)
-			if field == "" {
-				return fmt.Errorf("abi: purely underscored output cannot unpack to struct")
-			}
-			if exists[field] {
-				return fmt.Errorf("abi: multiple outputs mapping to the same struct field '%s'", field)
-			}
-			exists[field] = true
+		if err := requireUniqueStructFieldNames(arguments); err != nil {
+			return err
 		}
 	}
 	for i, arg := range arguments.NonIndexed() {
@@ -131,14 +123,9 @@ func (arguments Arguments) unpackTuple(v interface{}, marshalledValues []interfa
 
 		switch kind {
 		case reflect.Struct:
-			name := capitalise(arg.Name)
-			for j := 0; j < typ.NumField(); j++ {
-				// TODO read tags: `abi:"fieldName"`
-				if typ.Field(j).Name == name {
-					if err := set(value.Field(j), reflectValue, arg); err != nil {
-						return err
-					}
-				}
+			err := unpackStruct(value, reflectValue, arg)
+			if err != nil {
+				return err
 			}
 		case reflect.Slice, reflect.Array:
 			if value.Len() < i {
@@ -165,8 +152,20 @@ func (arguments Arguments) unpackAtomic(v interface{}, marshalledValues []interf
 		return fmt.Errorf("abi: wrong length, expected single value, got %d", len(marshalledValues))
 	}
 	elem := reflect.ValueOf(v).Elem()
+	kind := elem.Kind()
 	reflectValue := reflect.ValueOf(marshalledValues[0])
+
+	if kind == reflect.Struct {
+		//make sure names don't collide
+		if err := requireUniqueStructFieldNames(arguments); err != nil {
+			return err
+		}
+
+		return unpackStruct(elem, reflectValue, arguments[0])
+	}
+
 	return set(elem, reflectValue, arguments.NonIndexed()[0])
+
 }
 
 // Computes the full size of an array;
@@ -278,3 +277,18 @@ func capitalise(input string) string {
 	}
 	return strings.ToUpper(input[:1]) + input[1:]
 }
+
+//unpackStruct extracts each argument into its corresponding struct field
+func unpackStruct(value, reflectValue reflect.Value, arg Argument) error {
+	name := capitalise(arg.Name)
+	typ := value.Type()
+	for j := 0; j < typ.NumField(); j++ {
+		// TODO read tags: `abi:"fieldName"`
+		if typ.Field(j).Name == name {
+			if err := set(value.Field(j), reflectValue, arg); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}

accounts/abi/reflect.go

@@ -110,3 +110,19 @@ func requireUnpackKind(v reflect.Value, t reflect.Type, k reflect.Kind,
 	}
 	return nil
 }
+
+// requireUniqueStructFieldNames makes sure field names don't collide
+func requireUniqueStructFieldNames(args Arguments) error {
+	exists := make(map[string]bool)
+	for _, arg := range args {
+		field := capitalise(arg.Name)
+		if field == "" {
+			return fmt.Errorf("abi: purely underscored output cannot unpack to struct")
+		}
+		if exists[field] {
+			return fmt.Errorf("abi: multiple outputs mapping to the same struct field '%s'", field)
+		}
+		exists[field] = true
+	}
+	return nil
+}