add the struct package english docs (#82)

docs/structs/field.md

@@ -0,0 +1,353 @@
+# Field
+
+Field is abstract struct field for provide several high level functions
+
+<div STYLE="page-break-after: always;"></div>
+
+## Source:
+
+-   [https://github.com/duke-git/lancet/blob/main/structs/field.go](https://github.com/duke-git/lancet/blob/main/structs/field.go)
+
+<div STYLE="page-break-after: always;"></div>
+
+## Usage:
+
+```go
+import (
+    "github.com/duke-git/lancet/v2/structs"
+)
+```
+
+<div STYLE="page-break-after: always;"></div>
+
+## Index:
+-   [Tag](#Tag)
+-   [Name](#Name)
+-   [Value](#Value)
+-   [Kind](#Kind)
+-   [IsEmbedded](#IsEmbedded)
+-   [IsExported](#IsExported)
+-   [IsZero](#IsZero)
+-   [IsSlice](#IsSlice)
+
+> Note：Since `Field` inherits from `Struct`, it also has all the methods of 'Struct', as follows:
+
+-   [ToMap](https://github.com/duke-git/lancet/blob/main/docs/structs/struct.md#ToMap)
+-   [Fields](https://github.com/duke-git/lancet/blob/main/docs/structs/struct.md#Fields)
+-   [Field](https://github.com/duke-git/lancet/blob/main/docs/structs/struct.md#Field)
+-   [IsStruct](https://github.com/duke-git/lancet/blob/main/docs/structs/struct.md#IsStruct)
+
+<div STYLE="page-break-after: always;"></div>
+
+## Documentation:
+
+### <span id="Tag">Tag</span>
+
+<p>Get a `Tag` of the `Field`, `Tag` is a abstract struct field tag</p>
+
+<b>Signature:</b>
+
+```go
+func (f *Field) Tag() *Tag
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/structs"
+)
+
+func main() {
+	type Parent struct {
+		Name string `json:"name,omitempty"`
+	}
+	p1 := &Parent{"111"}
+
+	s := structs.New(p1)
+	n, _ := s.Field("Name")
+	tag := n.Tag()
+
+	fmt.Println(tag.Name)
+	
+	// Output:
+	// name
+}
+```
+
+### <span id="Value">Value</span>
+
+<p>Get the `Field` underlying value</p>
+
+<b>Signature:</b>
+
+```go
+func (f *Field) Value() any
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/structs"
+)
+
+func main() {
+	type Parent struct {
+		Name string `json:"name,omitempty"`
+	}
+	p1 := &Parent{"111"}
+
+	s := structs.New(p1)
+	n, _ := s.Field("Name")
+	
+	fmt.Println(n.Value())
+	
+	// Output: 
+	// 111
+}
+```
+
+### <span id="IsEmbedded">IsEmbedded</span>
+
+<p>Check if the field is an embedded field</p>
+
+<b>Signature:</b>
+
+```go
+func (f *Field) IsEmbedded() bool
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/structs"
+)
+
+func main() {
+	type Parent struct {
+		Name string
+	}
+	type Child struct {
+		Parent
+		Age int
+	}
+	c1 := &Child{}
+	c1.Name = "111"
+	c1.Age = 11
+
+	s := structs.New(c1)
+	n, _ := s.Field("Name")
+	a, _ := s.Field("Age")
+	
+	fmt.Println(n.IsEmbedded())
+	fmt.Println(a.IsEmbedded())
+	
+	// Output: 
+	// true
+	// false
+}
+```
+
+### <span id="IsExported">IsExported</span>
+
+<p>Check if the field is exported</p>
+
+<b>Signature:</b>
+
+```go
+func (f *Field) IsExported() bool
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/structs"
+)
+
+func main() {
+	type Parent struct {
+		Name string
+		age  int
+	}
+	p1 := &Parent{Name: "11", age: 11}
+	s := structs.New(p1)
+	n, _ := s.Field("Name")
+	a, _ := s.Field("age")
+	
+	fmt.Println(n.IsExported())
+	fmt.Println(a.IsExported())
+	
+	// Output: 
+	// true
+	// false
+}
+```
+
+### <span id="IsZero">IsZero</span>
+
+<p>Check if the field is zero value</p>
+
+<b>Signature:</b>
+
+```go
+func (f *Field) IsZero() bool
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/structs"
+)
+
+func main() {
+	type Parent struct {
+		Name string
+		Age  int
+	}
+	p1 := &Parent{Age: 11}
+	s := structs.New(p1)
+	n, _ := s.Field("Name")
+	a, _ := s.Field("Age")
+	
+	fmt.Println(n.IsZero())
+	fmt.Println(a.IsZero())
+	
+	// Output: 
+	// true
+	// false
+}
+```
+
+### <span id="Name">Name</span>
+
+<p>Get the field name</p>
+
+<b>Signature:</b>
+
+```go
+func (f *Field) Name() string
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/structs"
+)
+
+func main() {
+	type Parent struct {
+		Name string
+		Age  int
+	}
+	p1 := &Parent{Age: 11}
+	s := structs.New(p1)
+	n, _ := s.Field("Name")
+	a, _ := s.Field("Age")
+	
+	fmt.Println(n.Name())
+	fmt.Println(a.Name())
+	
+	// Output: 
+	// Name
+	// Age
+}
+```
+
+### <span id="Kind">Kind</span>
+
+<p>Get the field's kind</p>
+
+<b>Signature:</b>
+
+```go
+func (f *Field) Kind() reflect.Kind
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/structs"
+)
+
+func main() {
+	type Parent struct {
+		Name string
+		Age  int
+	}
+	p1 := &Parent{Age: 11}
+	s := structs.New(p1)
+	n, _ := s.Field("Name")
+	a, _ := s.Field("Age")
+	
+	fmt.Println(n.Kind())
+	fmt.Println(a.Kind())
+	
+	// Output: 
+	// string
+	// int
+}
+```
+
+### <span id="IsSlice">IsSlice</span>
+
+<p>Check if the field is a slice</p>
+
+<b>Signature:</b>
+
+```go
+func (f *Field) IsSlice() bool
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/structs"
+)
+
+func main() {
+	type Parent struct {
+		Name string
+		arr  []int
+	}
+
+	p1 := &Parent{arr: []int{1, 2, 3}}
+	s := structs.New(p1)
+	a, _ := s.Field("arr")
+	
+	fmt.Println(a.IsSlice())
+	
+	// Output: 
+	// true
+}
+```