https://github.com/tiendc/go-rflutil
Reflection utility functions for Go
https://github.com/tiendc/go-rflutil
golang reflect reflection struct
Last synced: 3 months ago
JSON representation
Reflection utility functions for Go
- Host: GitHub
- URL: https://github.com/tiendc/go-rflutil
- Owner: tiendc
- License: mit
- Created: 2023-07-26T08:15:54.000Z (almost 3 years ago)
- Default Branch: main
- Last Pushed: 2024-09-19T18:45:12.000Z (almost 2 years ago)
- Last Synced: 2025-04-06T07:37:42.751Z (over 1 year ago)
- Topics: golang, reflect, reflection, struct
- Language: Go
- Homepage:
- Size: 51.8 KB
- Stars: 3
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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# Reflection utility functions for Go
## Installation
```shell
go get github.com/tiendc/go-rflutil
```
## Usage
- [Slice functions](#slice-functions)
- [Map functions](#map-functions)
- [Struct functions](#struct-functions)
- [Common functions](#common-functions)
### Slice functions
#### SliceLen
```go
slice := []int{1, 2, 3}
v, err := SliceLen(reflect.ValueOf(slice)) // v == 3
```
#### SliceGet
```go
slice := []int{1, 2, 3}
v, err := SliceGet[int](reflect.ValueOf(slice), 1) // v == 2
v, err := SliceGet[int](reflect.ValueOf(slice), 3) // err is ErrIndexOutOfRange
v, err := SliceGet[string](reflect.ValueOf(slice), 1) // err is ErrTypeUnmatched
```
#### SliceSet
```go
slice := []int{1, 2, 3}
err := SliceSet(reflect.ValueOf(slice), 1, 22) // slice[1] == 22
err := SliceSet(reflect.ValueOf(slice), 3, 44) // err is ErrIndexOutOfRange
err := SliceSet(reflect.ValueOf(slice), 1, "22") // err is ErrTypeUnmatched
```
#### SliceAppend
```go
slice := []int{1, 2, 3}
slice2, err := SliceAppend(reflect.ValueOf(slice), 4) // slice2 == []int{1, 2, 3, 4}
slice2, err := SliceAppend(reflect.ValueOf(slice), "4") // err is ErrTypeUnmatched
```
#### SliceGetAll
```go
slice := []int{1, 2, 3}
s, err := SliceGetAll(reflect.ValueOf(slice)) // returns []reflect.Value
```
#### SliceAs
```go
slice := []any{1, 2, 3}
s, err := SliceAs[int64](reflect.ValueOf(slice)) // s == []int64{1,2,3}
```
### Map functions
#### MapLen
```go
aMap := map[int]string{1: "11", 2: "22", 3: "33"}
v, err := MapLen(reflect.ValueOf(aMap), 1) // v == 3
```
#### MapGet
```go
aMap := map[int]string{1: "11", 2: "22", 3: "33"}
v, err := MapGet[string](reflect.ValueOf(aMap), 1) // v == "11"
v, err := MapGet[int](reflect.ValueOf(aMap), 3) // err is ErrTypeUnmatched
```
#### MapSet
```go
aMap := map[int]string{1: "11", 2: "22", 3: "33"}
err := MapSet(reflect.ValueOf(aMap), 1, "111") // success
err := MapSet(reflect.ValueOf(aMap), 4, "444") // success
err := MapSet(reflect.ValueOf(aMap), 5, 555) // err is ErrTypeUnmatched
```
#### MapDelete
```go
aMap := map[int]string{1: "11", 2: "22", 3: "33"}
err := MapDelete(reflect.ValueOf(aMap), 1) // success
err := MapDelete(reflect.ValueOf(aMap), 4) // success
```
#### MapKeys
```go
aMap := map[int]string{1: "11", 2: "22", 3: "33"}
keys, err := MapKeys(reflect.ValueOf(aMap)) // returns a slice []reflect.Value of keys
```
#### MapEntries
```go
aMap := map[int]string{1: "11", 2: "22", 3: "33"}
entries, err := MapEntries(reflect.ValueOf(aMap)) // returns a slice []MapEntry of entries
```
### Struct functions
#### StructGetField
```go
type Struct struct {
I int
S string
}
s := Struct{I: 1, S: "11"}
v, err := StructGetField[int](reflect.ValueOf(s), "I", true) // v == 1
v, err := StructGetField[string](reflect.ValueOf(s), "S", true) // v == "11"
v, err := StructGetField[string](reflect.ValueOf(s), "s", false) // v == "11"
v, err := StructGetField[string](reflect.ValueOf(s), "s", true) // err is ErrNotFound
```
#### StructSetField
```go
type Struct struct {
I int
S string
}
s := Struct{I: 1, S: "11"}
err := StructSetField[int](reflect.ValueOf(&s), "I", 11, true) // success
err := StructSetField[string](reflect.ValueOf(&s), "S", "111", true) // success
err := StructSetField[string](reflect.ValueOf(&s), "s", "111", false) // success
err := StructSetField[string](reflect.ValueOf(&s), "s", "111", true) // err is ErrNotFound
```
#### StructListFields
```go
type Base struct {
I int
S2 string
}
type Struct struct {
Base
I int
S string
}
s := Struct{}
fields, err := StructListFields(reflect.ValueOf(&s), false) // returns []string{"Base", "I", "S"}
fields, err := StructListFields(reflect.ValueOf(&s), true) // returns []string{"S2", "I", "S"}
```
#### StructToMap
```go
type Base struct {
I int `json:"i"`
S2 string `json:"s2"`
}
type Struct struct {
Base
I int `json:"i"`
S string `json:"s"`
}
s := Struct{I: 1, S: "S", Base: Base{I: 2, S2: "S2"}}
// Converts without flattening the embedded struct
m, err := StructToMap(reflect.ValueOf(&s), "", false) // m == map[string]any{"Base": Base{I: 2, S2: "S2"}, "I": 1, "S": "S"}
// Converts with flattening the embedded struct
m, err := StructToMap(reflect.ValueOf(&s), "", true) // m == map[string]any{"S2": "S2", "I": 1, "S": "S"}
// Converts with parsing json tag
m, err := StructToMap(reflect.ValueOf(&s), "json", true) // m == map[string]any{"s2": "S2", "i": 1, "s": "S"}
```
#### ParseTag / ParseTagOf / ParseTagsOf
```go
type S struct {
I int `mytag:"i,optional,k=v"`
S string `mytag:"s,optional,k1=v1,k2=v2,omitempty"`
U uint `mytag:"-,optional"`
}
s := S{I: 1, S: "11", U: 10}
sVal := reflect.ValueOf(s)
iField, _ := sVal.Type().FieldByName("I")
tag, err := ParseTag(&iField, "mytag", ",") // tag.Name == i
// tag.Attrs == map[string]string{"optional": "", "k", "v"}
```
### Common functions
#### ValueAs
```go
v, err := ValueAs[float32](reflect.ValueOf(97)) // v == float32(97)
v, err := ValueAs[string](reflect.ValueOf(97)) // v == "a"
```
## Contributing
- You are welcome to make pull requests for new functions and bug fixes.
## License
- [MIT License](LICENSE)
[doc-img]: https://pkg.go.dev/badge/github.com/tiendc/go-rflutil
[doc]: https://pkg.go.dev/github.com/tiendc/go-rflutil
[gover-img]: https://img.shields.io/badge/Go-%3E%3D%201.18-blue
[gover]: https://img.shields.io/badge/Go-%3E%3D%201.18-blue
[ci-img]: https://github.com/tiendc/go-rflutil/actions/workflows/go.yml/badge.svg
[ci]: https://github.com/tiendc/go-rflutil/actions/workflows/go.yml
[cov-img]: https://codecov.io/gh/tiendc/go-rflutil/branch/main/graph/badge.svg
[cov]: https://codecov.io/gh/tiendc/go-rflutil
[rpt-img]: https://goreportcard.com/badge/github.com/tiendc/go-rflutil
[rpt]: https://goreportcard.com/report/github.com/tiendc/go-rflutil