encoding/xml: add example and docs for anon fields

Anonymous pointer fields is not yet supported.
The problem is documented in issue 3108.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5694043

diff --git a/src/pkg/encoding/xml/example_test.go b/src/pkg/encoding/xml/example_test.go
index 6c5390766b10d6fda015183b7bd2518ce6dd6214..082ce6803d3b908289173fc23b9791ec31a9d79f 100644 (file)
--- a/src/pkg/encoding/xml/example_test.go
+++ b/src/pkg/encoding/xml/example_test.go
@@ -11,6 +11,9 @@ import (
 )
 
 func ExampleMarshalIndent() {
+       type Address struct {
+               City, State string
+       }
        type Person struct {
                XMLName   xml.Name `xml:"person"`
                Id        int      `xml:"id,attr"`
@@ -19,11 +22,13 @@ func ExampleMarshalIndent() {
                Age       int      `xml:"age"`
                Height    float32  `xml:"height,omitempty"`
                Married   bool
-               Comment   string `xml:",comment"`
+               Address
+               Comment string `xml:",comment"`
        }
 
        v := &Person{Id: 13, FirstName: "John", LastName: "Doe", Age: 42}
-       v.Comment = " Need more fields. "
+       v.Comment = " Need more details. "
+       v.Address = Address{"Hanga Roa", "Easter Island"}
 
        output, err := xml.MarshalIndent(v, "  ", "    ")
        if err != nil {
@@ -39,7 +44,9 @@ func ExampleMarshalIndent() {
        //       </name>
        //       <age>42</age>
        //       <Married>false</Married>
-       //       <!-- Need more fields. -->
+       //       <City>Hanga Roa</City>
+       //       <State>Easter Island</State>
+       //       <!-- Need more details. -->
        //   </person>
 }
 
@@ -52,14 +59,19 @@ func ExampleUnmarshal() {
                Where string `xml:"where,attr"`
                Addr  string
        }
+       type Address struct {
+               City, State string
+       }
        type Result struct {
                XMLName xml.Name `xml:"Person"`
                Name    string   `xml:"FullName"`
                Phone   string
                Email   []Email
                Groups  []string `xml:"Group>Value"`
+               Address
        }
-       p := Result{Name: "none", Phone: "none"}
+       v := Result{Name: "none", Phone: "none"}
+       v.Address = Address{"Hanga Roa", "Easter Island"}
 
        data := `
                <Person>
@@ -77,20 +89,22 @@ func ExampleUnmarshal() {
                        <Address>123 Main Street</Address>
                </Person>
        `
-       err := xml.Unmarshal([]byte(data), &p)
+       err := xml.Unmarshal([]byte(data), &v)
        if err != nil {
                fmt.Printf("error: %v", err)
                return
        }
-       fmt.Printf("XMLName: %#v\n", p.XMLName)
-       fmt.Printf("Name: %q\n", p.Name)
-       fmt.Printf("Phone: %q\n", p.Phone)
-       fmt.Printf("Email: %v\n", p.Email)
-       fmt.Printf("Groups: %v\n", p.Groups)
+       fmt.Printf("XMLName: %#v\n", v.XMLName)
+       fmt.Printf("Name: %q\n", v.Name)
+       fmt.Printf("Phone: %q\n", v.Phone)
+       fmt.Printf("Email: %v\n", v.Email)
+       fmt.Printf("Groups: %v\n", v.Groups)
+       fmt.Printf("Address: %v\n", v.Address)
        // Output:
        // XMLName: xml.Name{Space:"", Local:"Person"}
        // Name: "Grace R. Emlin"
        // Phone: "none"
        // Email: [{home gre@example.com} {work gre@work.com}]
        // Groups: [Friends Squash]
+       // Address: {Hanga Roa Easter Island}
 }

diff --git a/src/pkg/encoding/xml/marshal.go b/src/pkg/encoding/xml/marshal.go
index 25d88c4619b2d0d9cbb65b256d90f671ea561e5a..6c3170bdda3d42074b9721b9ac21ebc401e7f82d 100644 (file)
--- a/src/pkg/encoding/xml/marshal.go
+++ b/src/pkg/encoding/xml/marshal.go
@@ -57,6 +57,8 @@ const (
 //       if the field value is empty. The empty values are false, 0, any
 //       nil pointer or interface value, and any array, slice, map, or
 //       string of length zero.
+//     - a non-pointer anonymous struct field is handled as if the
+//       fields of its value were part of the outer struct.
 //
 // If a field uses a tag "a>b>c", then the element c will be nested inside
 // parent elements a and b.  Fields that appear next to each other that name

diff --git a/src/pkg/encoding/xml/read.go b/src/pkg/encoding/xml/read.go
index 7f5601a7ad1f9a365ff25f09e1f7fb901657c648..c2168242091a493f3c7af28e182c6da2aa32048c 100644 (file)
--- a/src/pkg/encoding/xml/read.go
+++ b/src/pkg/encoding/xml/read.go
@@ -81,6 +81,9 @@ import (
 //      of the above rules and the struct has a field with tag ",any",
 //      unmarshal maps the sub-element to that struct field.
 //
+//   * A non-pointer anonymous struct field is handled as if the
+//      fields of its value were part of the outer struct.
+//
 //   * A struct field with tag "-" is never unmarshalled into.
 //
 // Unmarshal maps an XML element to a string or []byte by saving the