ref

Documentation

Overview

implements extensions to the standard reflect lib suitable for implementing marshalling and unmarshalling packages. The main Mapper type allows for Go-compatible named attribute access, including accessing embedded struct attributes and the ability to use functions and struct tags to customize field names.

Index

• Variables
• func ArrayGet(a any, idxs ...int) (any, error)
• func ArrayLen(a any) (int, error)
• func ArrayOf[T any](args ...T) []T
• func ArraySet(a any, i int, v any) (any, error)
• func Convert(v any, t reflect.Type) (cv any, err error)
• func DerefType(t reflect.Type) reflect.Type
• func DerefValue(v reflect.Value) reflect.Value
• func FieldByIndexes(v reflect.Value, indexes []int) reflect.Value
• func FieldByIndexesReadOnly(v reflect.Value, indexes []int) reflect.Value
• func IsArrayType(v any) bool
• func IsComplexType(v any) bool
• func IsFloatType(v any) bool
• func IsIntType(v any) bool
• func IsMapType(v any) bool
• func IsPtrType(v any) bool
• func IsSliceType(v any) bool
• func MapGet(dict any, keys ...any) (any, error)
• func MapSet(dict any, key, val any) (any, error)
• func SetProperty(o any, k string, v any) (err error)
• type FieldInfo
• type Mapper
  • func NewMapper(tagName string) *Mapper
  • func NewMapperFunc(tagName string, f func(string) string) *Mapper
  • func NewMapperTagFunc(tagName string, mapFunc, tagMapFunc func(string) string) *Mapper
  • func (m *Mapper) FieldByName(v reflect.Value, name string) reflect.Value
  • func (m *Mapper) FieldMap(v reflect.Value) map[string]reflect.Value
  • func (m *Mapper) FieldsByName(v reflect.Value, names []string) []reflect.Value
  • func (m *Mapper) TraversalsByName(t reflect.Type, names []string) [][]int
  • func (m *Mapper) TraversalsByNameFunc(t reflect.Type, names []string, fn func(int, []int) error) error
  • func (m *Mapper) TypeMap(t reflect.Type) *StructMap
• type StructMap
  • func (f StructMap) GetByPath(path string) *FieldInfo
  • func (f StructMap) GetByTraversal(index []int) *FieldInfo

Variables

var (
	TypeString   = reflect.TypeOf("")
	TypeBool     = reflect.TypeOf(false)
	TypeByte     = reflect.TypeOf(byte(0))
	TypeRune     = reflect.TypeOf(rune(0))
	TypeInt      = reflect.TypeOf(int(0))
	TypeInt32    = reflect.TypeOf(int32(0))
	TypeInt64    = reflect.TypeOf(int64(0))
	TypeFloat32  = reflect.TypeOf(float32(0))
	TypeFloat64  = reflect.TypeOf(float64(0))
	TypeDuration = reflect.TypeOf(time.Duration(0))
	TypeTime     = reflect.TypeOf(time.Time{})
)

Functions

func ArrayGet

func ArrayGet(a any, idxs ...int) (any, error)

ArrayGet getting value from array or slice by index usage:

a := [][]string{
    { "0,0", "0,1" },
    { "1,0", "1,1" },
}

{{ArrayGet a 0 1 }} // return "0,1"

func ArrayLen

func ArrayLen(a any) (int, error)

func ArrayOf

func ArrayOf[T any](args ...T) []T

ArrayOf returns a []T{args[0], args[1], ...}

func ArraySet

func ArraySet(a any, i int, v any) (any, error)

ArraySet set value to the array or slice by index

func Convert

func Convert(v any, t reflect.Type) (cv any, err error)

Convert convert the value v to the specified Type t

func DerefType

func DerefType(t reflect.Type) reflect.Type

DerefType is Indirect for reflect.Type

func DerefValue

func DerefValue(v reflect.Value) reflect.Value

DerefValue is Indirect for reflect.Value

func FieldByIndexes

func FieldByIndexes(v reflect.Value, indexes []int) reflect.Value

FieldByIndexes returns a value for the field given by the struct traversal for the given value.

func FieldByIndexesReadOnly

func FieldByIndexesReadOnly(v reflect.Value, indexes []int) reflect.Value

FieldByIndexesReadOnly returns a value for a particular struct traversal, but is not concerned with allocating nil pointers because the value is going to be used for reading and not setting.

func IsArrayType

func IsArrayType(v any) bool

IsArrayType return true if v is a array

func IsComplexType

func IsComplexType(v any) bool

IsComplexType return true if v is a complex

func IsFloatType

func IsFloatType(v any) bool

IsFloatType return true if v is a float

func IsIntType

func IsIntType(v any) bool

IsIntType return true if v is an integer

func IsMapType

func IsMapType(v any) bool

IsMapType return true if v is a map

func IsPtrType

func IsPtrType(v any) bool

IsPtrType return true if v is a ptr

func IsSliceType

func IsSliceType(v any) bool

IsSliceType return true if v is a array

func MapGet

func MapGet(dict any, keys ...any) (any, error)

MapGet getting value from map by keys usage:

m := map[string]any{
    "a": 1,
    "1": map[string]float64{
        "c": 4,
    },
}

{{MapGet m "a" }} // return 1 {{MapGet m 1 "c" }} // return 4

func MapSet

func MapSet(dict any, key, val any) (any, error)

MapSet setting value to the map

func SetProperty

func SetProperty(o any, k string, v any) (err error)

Types

type FieldInfo

type FieldInfo struct {
	Index    []int
	Path     string
	Field    reflect.StructField
	Zero     reflect.Value
	Name     string
	Options  map[string]string
	Embedded bool
	Children []*FieldInfo
	Parent   *FieldInfo
}

A FieldInfo is metadata for a struct field.

type Mapper

type Mapper struct {
	// contains filtered or unexported fields
}

Mapper is a general purpose mapper of names to struct fields. A Mapper behaves like most marshallers in the standard library, obeying a field tag for name mapping but also providing a basic transform function.

func NewMapper

func NewMapper(tagName string) *Mapper

NewMapper returns a new mapper using the tagName as its struct field tag. If tagName is the empty string, it is ignored.

func NewMapperFunc

func NewMapperFunc(tagName string, f func(string) string) *Mapper

NewMapperFunc returns a new mapper which optionally obeys a field tag and a struct field name mapper func given by f. Tags will take precedence, but for any other field, the mapped name will be f(field.Name)

func NewMapperTagFunc

func NewMapperTagFunc(tagName string, mapFunc, tagMapFunc func(string) string) *Mapper

NewMapperTagFunc returns a new mapper which contains a mapper for field names AND a mapper for tag values. This is useful for tags like json which can have values like "name,omitempty".

func (*Mapper) FieldByName

func (m *Mapper) FieldByName(v reflect.Value, name string) reflect.Value

FieldByName returns a field by its mapped name as a reflect.Value. Panics if v's Kind is not Struct or v is not Indirectable to a struct Kind. Returns zero Value if the name is not found.

func (*Mapper) FieldMap

func (m *Mapper) FieldMap(v reflect.Value) map[string]reflect.Value

FieldMap returns the mapper's mapping of field names to reflect values. Panics if v's Kind is not Struct, or v is not Indirectable to a struct kind.

func (*Mapper) FieldsByName

func (m *Mapper) FieldsByName(v reflect.Value, names []string) []reflect.Value

FieldsByName returns a slice of values corresponding to the slice of names for the value. Panics if v's Kind is not Struct or v is not Indirectable to a struct Kind. Returns zero Value for each name not found.

func (*Mapper) TraversalsByName

func (m *Mapper) TraversalsByName(t reflect.Type, names []string) [][]int

TraversalsByName returns a slice of int slices which represent the struct traversals for each mapped name. Panics if t is not a struct or Indirectable to a struct. Returns empty int slice for each name not found.

func (*Mapper) TraversalsByNameFunc

func (m *Mapper) TraversalsByNameFunc(t reflect.Type, names []string, fn func(int, []int) error) error

TraversalsByNameFunc traverses the mapped names and calls fn with the index of each name and the struct traversal represented by that name. Panics if t is not a struct or Indirectable to a struct. Returns the first error returned by fn or nil.

func (*Mapper) TypeMap

func (m *Mapper) TypeMap(t reflect.Type) *StructMap

TypeMap returns a mapping of field strings to int slices representing the traversal down the struct to reach the field.

type StructMap

type StructMap struct {
	Tree  *FieldInfo
	Index []*FieldInfo
	Paths map[string]*FieldInfo
	Names map[string]*FieldInfo
}

A StructMap is an index of field metadata for a struct.

func (StructMap) GetByPath

func (f StructMap) GetByPath(path string) *FieldInfo

GetByPath returns a *FieldInfo for a given string path.

func (StructMap) GetByTraversal

func (f StructMap) GetByTraversal(index []int) *FieldInfo

GetByTraversal returns a *FieldInfo for a given integer path. It is analogous to reflect.FieldByIndex, but using the cached traversal rather than re-executing the reflect machinery each time.