Refactor: remove redundant code and update README

tiendc · Sep 22, 2024 · c2c759b · c2c759b
1 parent 979a151
commit c2c759b
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Showing 7 changed files with 32 additions and 59 deletions.
diff --git a/README.md b/README.md
@@ -24,7 +24,7 @@ go get github.com/tiendc/go-deepcopy
 - [Copy between struct fields with different names](#copy-between-struct-fields-with-different-names)
 - [Ignore copying struct fields](#ignore-copying-struct-fields)
 - [Copy between struct fields and methods](#copy-between-struct-fields-and-methods)
-- [Copy from source having embedded structs](#copy-from-source-having-embedded-structs)
+- [Copy between inherited fields from embedded structs](#copy-between-inherited-fields-from-embedded-structs)
 - [Copy between unexported struct fields](#copy-between-unexported-struct-fields)
 - [Configure copying behavior](#configure-copying-behavior)
 
@@ -124,6 +124,8 @@ go get github.com/tiendc/go-deepcopy
 
 ### Copy between struct fields and methods
 
+- **Note**: If a copying method is defined in a struct, it will have higher priority than matching field.
+
   [Playground 1](https://go.dev/play/p/zb2NU32G2mG) /
   [Playground 2](https://go.dev/play/p/C3FpFwzoPFm)
 
@@ -159,35 +161,26 @@ func (d *D) CopyX(i int) error {
     // {x:11 U:22}
 ```
 
-### Copy from source having embedded structs
+### Copy between inherited fields from embedded structs
 
-  [Playground 1](https://go.dev/play/p/e7nvdqqZ6MF) /
-  [Playground 2](https://go.dev/play/p/UF8ppU5kD7v) /
-  [Playground 3](https://go.dev/play/p/YrCwKkHvyIe)
+- This is default behaviour from version 1.0, for lower versions, you can use custom copying function
+to achieve the same result.
 
 ```go
-// Source struct has embedded struct
-type SBase struct {
-    St string
-}
-type S struct {
-    SBase
-    I int
-}
-// but destination struct doesn't
-type D struct {
-    I  int
-    St string
-}
+    type SBase struct {
+        St string
+    }
+    // Source struct has embedded struct
+    type S struct {
+        SBase
+        I int
+    }
+    // but destination struct doesn't
+    type D struct {
+        I  int
+        St string
+    }
 
-// You want to copy `S.SBase.St` to `D.St`
-func (d *D) CopySBase(sb SBase) error {
-    // you can even call deepcopy.Copy(d, sb) if SBase has many fields
-    d.St = sb.St
-    return nil
-}
-```
-```go
     src := []S{{I: 1, SBase: SBase{"abc"}}, {I: 11, SBase: SBase{"xyz"}}}
     var dst []D
     _ = deepcopy.Copy(&dst, src)

diff --git a/base_copier.go b/base_copier.go
@@ -48,7 +48,7 @@ type ptr2ValueCopier struct {
 func (c *ptr2ValueCopier) Copy(dst, src reflect.Value) error {
 	src = src.Elem()
 	if !src.IsValid() {
-		dst.Set(reflect.Zero(dst.Type())) // TODO: Go1.18 has no SetZero
+		dst.Set(reflect.Zero(dst.Type())) // NOTE: Go1.18 has no SetZero
 		return nil
 	}
 	return c.copier.Copy(dst, src)
@@ -69,7 +69,7 @@ type ptr2PtrCopier struct {
 func (c *ptr2PtrCopier) Copy(dst, src reflect.Value) error {
 	src = src.Elem()
 	if !src.IsValid() {
-		dst.Set(reflect.Zero(dst.Type())) // TODO: Go1.18 has no SetZero
+		dst.Set(reflect.Zero(dst.Type())) // NOTE: Go1.18 has no SetZero
 		return nil
 	}
 	if dst.IsNil() {

diff --git a/build_copier.go b/build_copier.go
@@ -96,7 +96,8 @@ func defaultContext() *Context {
 }
 
 // buildCopier build copier for handling copy from `srcType` to `dstType`
-// nolint: gocognit, gocyclo
+//
+//nolint:gocognit,gocyclo
 func buildCopier(ctx *Context, dstType, srcType reflect.Type) (copier, error) {
 	dstKind, srcKind := dstType.Kind(), srcType.Kind()
 	if dstKind == reflect.Interface {
@@ -106,7 +107,7 @@ func buildCopier(ctx *Context, dstType, srcType reflect.Type) (copier, error) {
 		return &fromIfaceCopier{ctx: ctx}, nil
 	}
 
-	// nolint: nestif
+	//nolint:nestif
 	if srcKind == reflect.Pointer {
 		if dstKind == reflect.Pointer { // ptr -> ptr
 			copier := &ptr2PtrCopier{ctx: ctx}

diff --git a/deepcopy_test.go b/deepcopy_test.go
@@ -182,7 +182,7 @@ var (
 		M1: map[int]string{1: "11", 2: "22", 3: "33"},
 		M2: nil,
 		M3: map[int]int{7: 77, 8: 88, 9: 99},
-		// nolint: gofmt
+		//nolint:gofmt
 		M4: map[[3]int]*srcStruct2{
 			[3]int{1, 1, 1}: &srcStructA,
 			[3]int{2, 2, 2}: &srcStructB,

diff --git a/iface_copier.go b/iface_copier.go
@@ -14,7 +14,7 @@ func (c *fromIfaceCopier) Copy(dst, src reflect.Value) error {
 	for src.Kind() == reflect.Interface {
 		src = src.Elem()
 		if !src.IsValid() {
-			dst.Set(reflect.Zero(dst.Type())) // TODO: Go1.18 has no SetZero
+			dst.Set(reflect.Zero(dst.Type())) // NOTE: Go1.18 has no SetZero
 			return nil
 		}
 	}
@@ -35,7 +35,7 @@ func (c *toIfaceCopier) Copy(dst, src reflect.Value) error {
 	for src.Kind() == reflect.Interface {
 		src = src.Elem()
 		if !src.IsValid() {
-			dst.Set(reflect.Zero(dst.Type())) // TODO: Go1.18 has no SetZero
+			dst.Set(reflect.Zero(dst.Type())) // NOTE: Go1.18 has no SetZero
 			return nil
 		}
 	}

diff --git a/map_copier.go b/map_copier.go
@@ -14,7 +14,7 @@ type mapCopier struct {
 // Copy implementation of Copy function for map copier
 func (c *mapCopier) Copy(dst, src reflect.Value) (err error) {
 	if src.IsNil() {
-		dst.Set(reflect.Zero(dst.Type())) // TODO: Go1.18 has no SetZero
+		dst.Set(reflect.Zero(dst.Type())) // NOTE: Go1.18 has no SetZero
 		return nil
 	}
 	if dst.IsNil() {

diff --git a/slice_copier.go b/slice_copier.go
@@ -16,7 +16,7 @@ func (c *sliceCopier) Copy(dst, src reflect.Value) error {
 	if dst.Kind() == reflect.Slice { // Slice/Array -> Slice
 		// `src` is nil slice, set `dst` nil
 		if src.Kind() == reflect.Slice && src.IsNil() {
-			dst.Set(reflect.Zero(dst.Type())) // TODO: Go1.18 has no SetZero
+			dst.Set(reflect.Zero(dst.Type())) // NOTE: Go1.18 has no SetZero
 			return nil
 		}
 		newSlice := reflect.MakeSlice(dst.Type(), srcLen, srcLen)
@@ -42,7 +42,7 @@ func (c *sliceCopier) Copy(dst, src reflect.Value) error {
 	}
 	for ; i < dstLen; i++ {
 		item := dst.Index(i)
-		item.Set(reflect.Zero(item.Type())) // TODO: Go1.18 has no SetZero
+		item.Set(reflect.Zero(item.Type())) // NOTE: Go1.18 has no SetZero
 	}
 	return nil
 }
@@ -54,11 +54,11 @@ func (c *sliceCopier) init(dstType, srcType reflect.Type) (err error) {
 	// OPTIMIZATION: buildCopier() can handle this nicely, but it will add another wrapping layer
 	if simpleKindMask&(1<<srcKind) > 0 {
 		if srcType == dstType {
-			c.itemCopier = &sliceItemDirectCopier{}
+			c.itemCopier = &directCopier{}
 			return nil
 		}
 		if srcType.ConvertibleTo(dstType) {
-			c.itemCopier = &sliceItemConvCopier{}
+			c.itemCopier = &convCopier{}
 			return nil
 		}
 	}
@@ -77,24 +77,3 @@ func (c *sliceCopier) init(dstType, srcType reflect.Type) (err error) {
 	c.itemCopier, err = buildCopier(c.ctx, dstType, srcType)
 	return
 }
-
-// sliceItemDirectCopier copier that copies from a slice item to a destination value directly
-type sliceItemDirectCopier struct {
-}
-
-// Copy implementation of Copy function for slice item copier direct
-func (c *sliceItemDirectCopier) Copy(dst, src reflect.Value) error {
-	dst.Set(src)
-	return nil
-}
-
-// sliceItemConvCopier copier that copies from a slice item to a destination value
-// with converting `src` value to `dst` type
-type sliceItemConvCopier struct {
-}
-
-// Copy implementation of Copy function for slice item copier with-conversion
-func (c *sliceItemConvCopier) Copy(dst, src reflect.Value) error {
-	dst.Set(src.Convert(dst.Type()))
-	return nil
-}