reflect: support for struct tag use by multiple packages
Each package using struct field tags assumes that
it is the only package storing data in the tag.
This CL adds support in package reflect for sharing
tags between multiple packages. In this scheme, the
tags must be of the form
key:"value" key2:"value2"
(raw strings help when writing that tag in Go source).
reflect.StructField's Tag field now has type StructTag
(a string type), which has method Get(key string) string
that returns the associated value.
Clients of json and xml will need to be updated.
Code that says
type T struct {
X int "name"
}
should become
type T struct {
X int `json:"name"` // or `xml:"name"`
}
Use govet to identify struct tags that need to be changed
to use the new syntax.
R=r, r, dsymonds, bradfitz, kevlar, fvbommel, n13m3y3r
CC=golang-dev
https://golang.org/cl/4645069
diff --git a/src/cmd/godoc/codewalk.go b/src/cmd/godoc/codewalk.go
index 54bebe8..74178ce 100644
--- a/src/cmd/godoc/codewalk.go
+++ b/src/cmd/godoc/codewalk.go
@@ -74,7 +74,7 @@
// A Codewalk represents a single codewalk read from an XML file.
type Codewalk struct {
- Title string "attr"
+ Title string `xml:"attr"`
File []string
Step []*Codestep
}
@@ -83,9 +83,9 @@
// A Codestep is a single step in a codewalk.
type Codestep struct {
// Filled in from XML
- Src string "attr"
- Title string "attr"
- XML string "innerxml"
+ Src string `xml:"attr"`
+ Title string `xml:"attr"`
+ XML string `xml:"innerxml"`
// Derived from Src; not in XML.
Err os.Error
diff --git a/src/cmd/govet/govet.go b/src/cmd/govet/govet.go
index 73bd2fa..2865267 100644
--- a/src/cmd/govet/govet.go
+++ b/src/cmd/govet/govet.go
@@ -15,6 +15,7 @@
"go/token"
"os"
"path/filepath"
+ "reflect"
"strconv"
"strings"
"utf8"
@@ -59,7 +60,7 @@
var err os.Error
skip, err = strconv.Atoi(name[colon+1:])
if err != nil {
- error(`illegal format for "Func:N" argument %q; %s`, name, err)
+ errorf(`illegal format for "Func:N" argument %q; %s`, name, err)
}
name = name[:colon]
}
@@ -93,7 +94,7 @@
fs := token.NewFileSet()
parsedFile, err := parser.ParseFile(fs, name, reader, 0)
if err != nil {
- error("%s: %s", name, err)
+ errorf("%s: %s", name, err)
return
}
file := &File{fs.File(parsedFile.Pos())}
@@ -121,7 +122,7 @@
done := make(chan bool)
go func() {
for e := range errors {
- error("walk error: %s", e)
+ errorf("walk error: %s", e)
}
done <- true
}()
@@ -132,7 +133,7 @@
// error formats the error to standard error, adding program
// identification and a newline
-func error(format string, args ...interface{}) {
+func errorf(format string, args ...interface{}) {
fmt.Fprintf(os.Stderr, "govet: "+format+"\n", args...)
setExit(2)
}
@@ -185,15 +186,35 @@
// Visit implements the ast.Visitor interface.
func (f *File) Visit(node ast.Node) ast.Visitor {
- // TODO: could return nil for nodes that cannot contain a CallExpr -
- // will shortcut traversal. Worthwhile?
switch n := node.(type) {
case *ast.CallExpr:
f.checkCallExpr(n)
+ case *ast.Field:
+ f.checkFieldTag(n)
}
return f
}
+// checkField checks a struct field tag.
+func (f *File) checkFieldTag(field *ast.Field) {
+ if field.Tag == nil {
+ return
+ }
+
+ tag, err := strconv.Unquote(field.Tag.Value)
+ if err != nil {
+ f.Warnf(field.Pos(), "unable to read struct tag %s", field.Tag.Value)
+ return
+ }
+
+ // Check tag for validity by appending
+ // new key:value to end and checking that
+ // the tag parsing code can find it.
+ if reflect.StructTag(tag+` _gofix:"_magic"`).Get("_gofix") != "_magic" {
+ f.Warnf(field.Pos(), "struct field tag %s not compatible with reflect.StructTag.Get", field.Tag.Value)
+ return
+ }
+}
// checkCallExpr checks a call expression.
func (f *File) checkCallExpr(call *ast.CallExpr) {
@@ -373,6 +394,10 @@
f.Warnf(0, "%s", "hello", 3) // wrong # %s in call to added function
}
+type BadTypeUsedInTests struct {
+ X int "hello" // struct field not well-formed
+}
+
// printf is used by the test.
func printf(format string, args ...interface{}) {
panic("don't call - testing only")
diff --git a/src/pkg/asn1/asn1.go b/src/pkg/asn1/asn1.go
index 2650ef2..95f299e 100644
--- a/src/pkg/asn1/asn1.go
+++ b/src/pkg/asn1/asn1.go
@@ -707,7 +707,7 @@
if i == 0 && field.Type == rawContentsType {
continue
}
- innerOffset, err = parseField(val.Field(i), innerBytes, innerOffset, parseFieldParameters(field.Tag))
+ innerOffset, err = parseField(val.Field(i), innerBytes, innerOffset, parseFieldParameters(field.Tag.Get("asn1")))
if err != nil {
return
}
diff --git a/src/pkg/asn1/asn1_test.go b/src/pkg/asn1/asn1_test.go
index 463dbe0..3c94786 100644
--- a/src/pkg/asn1/asn1_test.go
+++ b/src/pkg/asn1/asn1_test.go
@@ -299,11 +299,11 @@
}
type TestContextSpecificTags struct {
- A int "tag:1"
+ A int `asn1:"tag:1"`
}
type TestContextSpecificTags2 struct {
- A int "explicit,tag:1"
+ A int `asn1:"explicit,tag:1"`
B int
}
@@ -353,7 +353,7 @@
}
type TBSCertificate struct {
- Version int "optional,explicit,default:0,tag:0"
+ Version int `asn1:"optional,explicit,default:0,tag:0"`
SerialNumber RawValue
SignatureAlgorithm AlgorithmIdentifier
Issuer RDNSequence
diff --git a/src/pkg/asn1/marshal.go b/src/pkg/asn1/marshal.go
index 7212c91..d7eb63b 100644
--- a/src/pkg/asn1/marshal.go
+++ b/src/pkg/asn1/marshal.go
@@ -413,7 +413,7 @@
for i := startingField; i < t.NumField(); i++ {
var pre *forkableWriter
pre, out = out.fork()
- err = marshalField(pre, v.Field(i), parseFieldParameters(t.Field(i).Tag))
+ err = marshalField(pre, v.Field(i), parseFieldParameters(t.Field(i).Tag.Get("asn1")))
if err != nil {
return
}
diff --git a/src/pkg/asn1/marshal_test.go b/src/pkg/asn1/marshal_test.go
index a951763..03df5f1 100644
--- a/src/pkg/asn1/marshal_test.go
+++ b/src/pkg/asn1/marshal_test.go
@@ -30,23 +30,23 @@
}
type implicitTagTest struct {
- A int "implicit,tag:5"
+ A int `asn1:"implicit,tag:5"`
}
type explicitTagTest struct {
- A int "explicit,tag:5"
+ A int `asn1:"explicit,tag:5"`
}
type ia5StringTest struct {
- A string "ia5"
+ A string `asn1:"ia5"`
}
type printableStringTest struct {
- A string "printable"
+ A string `asn1:"printable"`
}
type optionalRawValueTest struct {
- A RawValue "optional"
+ A RawValue `asn1:"optional"`
}
type testSET []int
diff --git a/src/pkg/crypto/ocsp/ocsp.go b/src/pkg/crypto/ocsp/ocsp.go
index 57dbe7d..e725bde 100644
--- a/src/pkg/crypto/ocsp/ocsp.go
+++ b/src/pkg/crypto/ocsp/ocsp.go
@@ -43,7 +43,7 @@
type responseASN1 struct {
Status asn1.Enumerated
- Response responseBytes "explicit,tag:0"
+ Response responseBytes `asn1:"explicit,tag:0"`
}
type responseBytes struct {
@@ -55,30 +55,30 @@
TBSResponseData responseData
SignatureAlgorithm pkix.AlgorithmIdentifier
Signature asn1.BitString
- Certificates []asn1.RawValue "explicit,tag:0,optional"
+ Certificates []asn1.RawValue `asn1:"explicit,tag:0,optional"`
}
type responseData struct {
Raw asn1.RawContent
- Version int "optional,default:1,explicit,tag:0"
- RequestorName pkix.RDNSequence "optional,explicit,tag:1"
- KeyHash []byte "optional,explicit,tag:2"
+ Version int `asn1:"optional,default:1,explicit,tag:0"`
+ RequestorName pkix.RDNSequence `asn1:"optional,explicit,tag:1"`
+ KeyHash []byte `asn1:"optional,explicit,tag:2"`
ProducedAt *time.Time
Responses []singleResponse
}
type singleResponse struct {
CertID certID
- Good asn1.Flag "explicit,tag:0,optional"
- Revoked revokedInfo "explicit,tag:1,optional"
- Unknown asn1.Flag "explicit,tag:2,optional"
+ Good asn1.Flag `asn1:"explicit,tag:0,optional"`
+ Revoked revokedInfo `asn1:"explicit,tag:1,optional"`
+ Unknown asn1.Flag `asn1:"explicit,tag:2,optional"`
ThisUpdate *time.Time
- NextUpdate *time.Time "explicit,tag:0,optional"
+ NextUpdate *time.Time `asn1:"explicit,tag:0,optional"`
}
type revokedInfo struct {
RevocationTime *time.Time
- Reason int "explicit,tag:0,optional"
+ Reason int `asn1:"explicit,tag:0,optional"`
}
// This is the exposed reflection of the internal OCSP structures.
diff --git a/src/pkg/crypto/x509/pkix/pkix.go b/src/pkg/crypto/x509/pkix/pkix.go
index 7806b2a2..266fd55 100644
--- a/src/pkg/crypto/x509/pkix/pkix.go
+++ b/src/pkg/crypto/x509/pkix/pkix.go
@@ -16,7 +16,7 @@
// 5280, section 4.1.1.2.
type AlgorithmIdentifier struct {
Algorithm asn1.ObjectIdentifier
- Parameters asn1.RawValue "optional"
+ Parameters asn1.RawValue `asn1:"optional"`
}
type RDNSequence []RelativeDistinguishedNameSET
@@ -32,7 +32,7 @@
// 5280, section 4.2.
type Extension struct {
Id asn1.ObjectIdentifier
- Critical bool "optional"
+ Critical bool `asn1:"optional"`
Value []byte
}
@@ -149,13 +149,13 @@
// 5280, section 5.1.
type TBSCertificateList struct {
Raw asn1.RawContent
- Version int "optional,default:2"
+ Version int `asn1:"optional,default:2"`
Signature AlgorithmIdentifier
Issuer RDNSequence
ThisUpdate *time.Time
NextUpdate *time.Time
- RevokedCertificates []RevokedCertificate "optional"
- Extensions []Extension "tag:0,optional,explicit"
+ RevokedCertificates []RevokedCertificate `asn1:"optional"`
+ Extensions []Extension `asn1:"tag:0,optional,explicit"`
}
// RevokedCertificate represents the ASN.1 structure of the same name. See RFC
@@ -163,5 +163,5 @@
type RevokedCertificate struct {
SerialNumber *big.Int
RevocationTime *time.Time
- Extensions []Extension "optional"
+ Extensions []Extension `asn1:"optional"`
}
diff --git a/src/pkg/crypto/x509/x509.go b/src/pkg/crypto/x509/x509.go
index 8bafeda..348727a 100644
--- a/src/pkg/crypto/x509/x509.go
+++ b/src/pkg/crypto/x509/x509.go
@@ -30,11 +30,11 @@
P *big.Int
Q *big.Int
// We ignore these values, if present, because rsa will calculate them.
- Dp *big.Int "optional"
- Dq *big.Int "optional"
- Qinv *big.Int "optional"
+ Dp *big.Int `asn1:"optional"`
+ Dq *big.Int `asn1:"optional"`
+ Qinv *big.Int `asn1:"optional"`
- AdditionalPrimes []pkcs1AdditionalRSAPrime "optional"
+ AdditionalPrimes []pkcs1AdditionalRSAPrime `asn1:"optional"`
}
type pkcs1AdditionalRSAPrime struct {
@@ -136,16 +136,16 @@
type tbsCertificate struct {
Raw asn1.RawContent
- Version int "optional,explicit,default:1,tag:0"
+ Version int `asn1:"optional,explicit,default:1,tag:0"`
SerialNumber *big.Int
SignatureAlgorithm pkix.AlgorithmIdentifier
Issuer pkix.RDNSequence
Validity validity
Subject pkix.RDNSequence
PublicKey publicKeyInfo
- UniqueId asn1.BitString "optional,tag:1"
- SubjectUniqueId asn1.BitString "optional,tag:2"
- Extensions []pkix.Extension "optional,explicit,tag:3"
+ UniqueId asn1.BitString `asn1:"optional,tag:1"`
+ SubjectUniqueId asn1.BitString `asn1:"optional,tag:2"`
+ Extensions []pkix.Extension `asn1:"optional,explicit,tag:3"`
}
type dsaAlgorithmParameters struct {
@@ -168,7 +168,7 @@
// RFC 5280, 4.2.1.1
type authKeyId struct {
- Id []byte "optional,tag:0"
+ Id []byte `asn1:"optional,tag:0"`
}
type SignatureAlgorithm int
@@ -480,8 +480,8 @@
}
type basicConstraints struct {
- IsCA bool "optional"
- MaxPathLen int "optional"
+ IsCA bool `asn1:"optional"`
+ MaxPathLen int `asn1:"optional"`
}
type rsaPublicKey struct {
@@ -497,14 +497,14 @@
// RFC 5280, 4.2.1.10
type nameConstraints struct {
- Permitted []generalSubtree "optional,tag:0"
- Excluded []generalSubtree "optional,tag:1"
+ Permitted []generalSubtree `asn1:"optional,tag:0"`
+ Excluded []generalSubtree `asn1:"optional,tag:1"`
}
type generalSubtree struct {
- Name string "tag:2,optional,ia5"
- Min int "optional,tag:0"
- Max int "optional,tag:1"
+ Name string `asn1:"tag:2,optional,ia5"`
+ Min int `asn1:"optional,tag:0"`
+ Max int `asn1:"optional,tag:1"`
}
func parsePublicKey(algo PublicKeyAlgorithm, keyData *publicKeyInfo) (interface{}, os.Error) {
diff --git a/src/pkg/go/types/testdata/exports.go b/src/pkg/go/types/testdata/exports.go
index 1de2e00..035a13f 100644
--- a/src/pkg/go/types/testdata/exports.go
+++ b/src/pkg/go/types/testdata/exports.go
@@ -38,7 +38,7 @@
T9 struct {
a int
b, c float32
- d []string "tag"
+ d []string `go:"tag"`
}
T10 struct {
T8
diff --git a/src/pkg/json/decode.go b/src/pkg/json/decode.go
index e78b60c..35a06b0f 100644
--- a/src/pkg/json/decode.go
+++ b/src/pkg/json/decode.go
@@ -482,7 +482,7 @@
if isValidTag(key) {
for i := 0; i < sv.NumField(); i++ {
f = st.Field(i)
- if f.Tag == key {
+ if f.Tag.Get("json") == key {
ok = true
break
}
diff --git a/src/pkg/json/decode_test.go b/src/pkg/json/decode_test.go
index bf8bf10..9b84bc7 100644
--- a/src/pkg/json/decode_test.go
+++ b/src/pkg/json/decode_test.go
@@ -42,8 +42,9 @@
type badTag struct {
X string
- Y string "y"
- Z string "@#*%(#@"
+ Y string `json:"y"`
+ Z string `x:"@#*%(#@"`
+ W string `json:"@#$@#$"`
}
type unmarshalTest struct {
@@ -68,7 +69,7 @@
{`{"x": 1}`, new(tx), tx{}, &UnmarshalFieldError{"x", txType, txType.Field(0)}},
// skip invalid tags
- {`{"X":"a", "y":"b", "Z":"c"}`, new(badTag), badTag{"a", "b", "c"}, nil},
+ {`{"X":"a", "y":"b", "Z":"c", "W":"d"}`, new(badTag), badTag{"a", "b", "c", "d"}, nil},
// syntax errors
{`{"X": "foo", "Y"}`, nil, nil, &SyntaxError{"invalid character '}' after object key", 17}},
@@ -250,7 +251,7 @@
Float32 float32
Float64 float64
- Foo string "bar"
+ Foo string `json:"bar"`
PBool *bool
PInt *int
diff --git a/src/pkg/json/encode.go b/src/pkg/json/encode.go
index ec0a14a..adc0f0f 100644
--- a/src/pkg/json/encode.go
+++ b/src/pkg/json/encode.go
@@ -36,11 +36,13 @@
// Array and slice values encode as JSON arrays, except that
// []byte encodes as a base64-encoded string.
//
-// Struct values encode as JSON objects. Each struct field becomes
-// a member of the object. By default the object's key name is the
-// struct field name. If the struct field has a non-empty tag consisting
-// of only Unicode letters, digits, and underscores, that tag will be used
-// as the name instead. Only exported fields will be encoded.
+// Struct values encode as JSON objects. Each exported struct field
+// becomes a member of the object. By default the object's key string
+// is the struct field name. If the struct field's tag has a "json" key with a
+// value that is a non-empty string consisting of only Unicode letters,
+// digits, and underscores, that value will be used as the object key.
+// For example, the field tag `json:"myName"` says to use "myName"
+// as the object key.
//
// Map values encode as JSON objects.
// The map's key type must be string; the object keys are used directly
@@ -236,8 +238,8 @@
} else {
e.WriteByte(',')
}
- if isValidTag(f.Tag) {
- e.string(f.Tag)
+ if tag := f.Tag.Get("json"); tag != "" && isValidTag(tag) {
+ e.string(tag)
} else {
e.string(f.Name)
}
diff --git a/src/pkg/net/dnsmsg.go b/src/pkg/net/dnsmsg.go
index ade1bb3..640973b 100644
--- a/src/pkg/net/dnsmsg.go
+++ b/src/pkg/net/dnsmsg.go
@@ -93,7 +93,7 @@
// DNS queries.
type dnsQuestion struct {
- Name string "domain-name" // "domain-name" specifies encoding; see packers below
+ Name string `net:"domain-name"` // `net:"domain-name"` specifies encoding; see packers below
Qtype uint16
Qclass uint16
}
@@ -102,7 +102,7 @@
// There are many types of messages,
// but they all share the same header.
type dnsRR_Header struct {
- Name string "domain-name"
+ Name string `net:"domain-name"`
Rrtype uint16
Class uint16
Ttl uint32
@@ -121,7 +121,7 @@
type dnsRR_CNAME struct {
Hdr dnsRR_Header
- Cname string "domain-name"
+ Cname string `net:"domain-name"`
}
func (rr *dnsRR_CNAME) Header() *dnsRR_Header {
@@ -140,7 +140,7 @@
type dnsRR_MB struct {
Hdr dnsRR_Header
- Mb string "domain-name"
+ Mb string `net:"domain-name"`
}
func (rr *dnsRR_MB) Header() *dnsRR_Header {
@@ -149,7 +149,7 @@
type dnsRR_MG struct {
Hdr dnsRR_Header
- Mg string "domain-name"
+ Mg string `net:"domain-name"`
}
func (rr *dnsRR_MG) Header() *dnsRR_Header {
@@ -158,8 +158,8 @@
type dnsRR_MINFO struct {
Hdr dnsRR_Header
- Rmail string "domain-name"
- Email string "domain-name"
+ Rmail string `net:"domain-name"`
+ Email string `net:"domain-name"`
}
func (rr *dnsRR_MINFO) Header() *dnsRR_Header {
@@ -168,7 +168,7 @@
type dnsRR_MR struct {
Hdr dnsRR_Header
- Mr string "domain-name"
+ Mr string `net:"domain-name"`
}
func (rr *dnsRR_MR) Header() *dnsRR_Header {
@@ -178,7 +178,7 @@
type dnsRR_MX struct {
Hdr dnsRR_Header
Pref uint16
- Mx string "domain-name"
+ Mx string `net:"domain-name"`
}
func (rr *dnsRR_MX) Header() *dnsRR_Header {
@@ -187,7 +187,7 @@
type dnsRR_NS struct {
Hdr dnsRR_Header
- Ns string "domain-name"
+ Ns string `net:"domain-name"`
}
func (rr *dnsRR_NS) Header() *dnsRR_Header {
@@ -196,7 +196,7 @@
type dnsRR_PTR struct {
Hdr dnsRR_Header
- Ptr string "domain-name"
+ Ptr string `net:"domain-name"`
}
func (rr *dnsRR_PTR) Header() *dnsRR_Header {
@@ -205,8 +205,8 @@
type dnsRR_SOA struct {
Hdr dnsRR_Header
- Ns string "domain-name"
- Mbox string "domain-name"
+ Ns string `net:"domain-name"`
+ Mbox string `net:"domain-name"`
Serial uint32
Refresh uint32
Retry uint32
@@ -232,7 +232,7 @@
Priority uint16
Weight uint16
Port uint16
- Target string "domain-name"
+ Target string `net:"domain-name"`
}
func (rr *dnsRR_SRV) Header() *dnsRR_Header {
@@ -241,7 +241,7 @@
type dnsRR_A struct {
Hdr dnsRR_Header
- A uint32 "ipv4"
+ A uint32 `net:"ipv4"`
}
func (rr *dnsRR_A) Header() *dnsRR_Header {
@@ -250,7 +250,7 @@
type dnsRR_AAAA struct {
Hdr dnsRR_Header
- AAAA [16]byte "ipv6"
+ AAAA [16]byte `net:"ipv6"`
}
func (rr *dnsRR_AAAA) Header() *dnsRR_Header {
@@ -435,7 +435,7 @@
default:
fmt.Fprintf(os.Stderr, "net: dns: unknown string tag %v", f.Tag)
return len(msg), false
- case "domain-name":
+ case `net:"domain-name"`:
off, ok = packDomainName(s, msg, off)
if !ok {
return len(msg), false
@@ -506,7 +506,7 @@
default:
fmt.Fprintf(os.Stderr, "net: dns: unknown string tag %v", f.Tag)
return len(msg), false
- case "domain-name":
+ case `net:"domain-name"`:
s, off, ok = unpackDomainName(msg, off)
if !ok {
return len(msg), false
@@ -536,9 +536,9 @@
}
// Generic struct printer.
-// Doesn't care about the string tag "domain-name",
-// but does look for an "ipv4" tag on uint32 variables
-// and the "ipv6" tag on array variables,
+// Doesn't care about the string tag `net:"domain-name"`,
+// but does look for an `net:"ipv4"` tag on uint32 variables
+// and the `net:"ipv6"` tag on array variables,
// printing them as IP addresses.
func printStructValue(val reflect.Value) string {
s := "{"
@@ -553,10 +553,10 @@
fval := val.Field(i)
if fv := fval; fv.Kind() == reflect.Struct {
s += printStructValue(fv)
- } else if fv := fval; (fv.Kind() == reflect.Uint || fv.Kind() == reflect.Uint8 || fv.Kind() == reflect.Uint16 || fv.Kind() == reflect.Uint32 || fv.Kind() == reflect.Uint64 || fv.Kind() == reflect.Uintptr) && f.Tag == "ipv4" {
+ } else if fv := fval; (fv.Kind() == reflect.Uint || fv.Kind() == reflect.Uint8 || fv.Kind() == reflect.Uint16 || fv.Kind() == reflect.Uint32 || fv.Kind() == reflect.Uint64 || fv.Kind() == reflect.Uintptr) && f.Tag == `net:"ipv4"` {
i := fv.Uint()
s += IPv4(byte(i>>24), byte(i>>16), byte(i>>8), byte(i)).String()
- } else if fv := fval; fv.Kind() == reflect.Array && f.Tag == "ipv6" {
+ } else if fv := fval; fv.Kind() == reflect.Array && f.Tag == `net:"ipv6"` {
i := fv.Interface().([]byte)
s += IP(i).String()
} else {
diff --git a/src/pkg/reflect/all_test.go b/src/pkg/reflect/all_test.go
index 94b0fb5..34d74b3 100644
--- a/src/pkg/reflect/all_test.go
+++ b/src/pkg/reflect/all_test.go
@@ -127,17 +127,17 @@
},
{struct {
x struct {
- a int8 "hi there"
+ a int8 `reflect:"hi there"`
}
}{},
- `struct { a int8 "hi there" }`,
+ `struct { a int8 "reflect:\"hi there\"" }`,
},
{struct {
x struct {
- a int8 "hi \x00there\t\n\"\\"
+ a int8 `reflect:"hi \x00there\t\n\"\\"`
}
}{},
- `struct { a int8 "hi \x00there\t\n\"\\" }`,
+ `struct { a int8 "reflect:\"hi \\x00there\\t\\n\\\"\\\\\"" }`,
},
{struct {
x struct {
@@ -423,7 +423,7 @@
// make sure tag strings are not part of element type
typ = TypeOf(struct {
- d []uint32 "TAG"
+ d []uint32 `reflect:"TAG"`
}{}).Field(0).Type
testType(t, 14, typ, "[]uint32")
}
@@ -1544,3 +1544,23 @@
t.Errorf("after Fprintf CallSlice: %q != %q", b.String(), "hello 42 world")
}
}
+
+var tagGetTests = []struct {
+ Tag StructTag
+ Key string
+ Value string
+}{
+ {`protobuf:"PB(1,2)"`, `protobuf`, `PB(1,2)`},
+ {`protobuf:"PB(1,2)"`, `foo`, ``},
+ {`protobuf:"PB(1,2)"`, `rotobuf`, ``},
+ {`protobuf:"PB(1,2)" json:"name"`, `json`, `name`},
+ {`protobuf:"PB(1,2)" json:"name"`, `protobuf`, `PB(1,2)`},
+}
+
+func TestTagGet(t *testing.T) {
+ for _, tt := range tagGetTests {
+ if v := tt.Tag.Get(tt.Key); v != tt.Value {
+ t.Errorf("StructTag(%#q).Get(%#q) = %#q, want %#q", tt.Tag, tt.Key, v, tt.Value)
+ }
+ }
+}
diff --git a/src/pkg/reflect/type.go b/src/pkg/reflect/type.go
index f774f73..a120da7 100644
--- a/src/pkg/reflect/type.go
+++ b/src/pkg/reflect/type.go
@@ -274,7 +274,7 @@
// arrayType represents a fixed array type.
type arrayType struct {
- commonType "array"
+ commonType `reflect:"array"`
elem *runtime.Type
slice *runtime.Type
len uintptr
@@ -282,14 +282,14 @@
// chanType represents a channel type.
type chanType struct {
- commonType "chan"
+ commonType `reflect:"chan"`
elem *runtime.Type
dir uintptr
}
// funcType represents a function type.
type funcType struct {
- commonType "func"
+ commonType `reflect:"func"`
dotdotdot bool
in []*runtime.Type
out []*runtime.Type
@@ -304,26 +304,26 @@
// interfaceType represents an interface type.
type interfaceType struct {
- commonType "interface"
+ commonType `reflect:"interface"`
methods []imethod
}
// mapType represents a map type.
type mapType struct {
- commonType "map"
+ commonType `reflect:"map"`
key *runtime.Type
elem *runtime.Type
}
// ptrType represents a pointer type.
type ptrType struct {
- commonType "ptr"
+ commonType `reflect:"ptr"`
elem *runtime.Type
}
// sliceType represents a slice type.
type sliceType struct {
- commonType "slice"
+ commonType `reflect:"slice"`
elem *runtime.Type
}
@@ -338,7 +338,7 @@
// structType represents a struct type.
type structType struct {
- commonType "struct"
+ commonType `reflect:"struct"`
fields []structField
}
@@ -696,12 +696,72 @@
PkgPath string // empty for uppercase Name
Name string
Type Type
- Tag string
+ Tag StructTag
Offset uintptr
Index []int
Anonymous bool
}
+// A StructTag is the tag string in a struct field.
+//
+// By convention, tag strings are a concatenation of
+// optionally space-separated key:"value" pairs.
+// Each key is a non-empty string consisting of non-control
+// characters other than space (U+0020 ' '), quote (U+0022 '"'),
+// and colon (U+003A ':'). Each value is quoted using U+0022 '"'
+// characters and Go string literal syntax.
+type StructTag string
+
+// Get returns the value associated with key in the tag string.
+// If there is no such key in the tag, Get returns the empty string.
+// If the tag does not have the conventional format, the value
+// returned by Get is unspecified,
+func (tag StructTag) Get(key string) string {
+ for tag != "" {
+ // skip leading space
+ i := 0
+ for i < len(tag) && tag[i] == ' ' {
+ i++
+ }
+ tag = tag[i:]
+ if tag == "" {
+ break
+ }
+
+ // scan to colon.
+ // a space or a quote is a syntax error
+ i = 0
+ for i < len(tag) && tag[i] != ' ' && tag[i] != ':' && tag[i] != '"' {
+ i++
+ }
+ if i+1 >= len(tag) || tag[i] != ':' || tag[i+1] != '"' {
+ break
+ }
+ name := string(tag[:i])
+ tag = tag[i+1:]
+
+ // scan quoted string to find value
+ i = 1
+ for i < len(tag) && tag[i] != '"' {
+ if tag[i] == '\\' {
+ i++
+ }
+ i++
+ }
+ if i >= len(tag) {
+ break
+ }
+ qvalue := string(tag[:i+1])
+ tag = tag[i+1:]
+
+ if key == name {
+ value, _ := strconv.Unquote(qvalue)
+ return value
+ }
+ }
+ return ""
+}
+
// Field returns the i'th struct field.
func (t *structType) Field(i int) (f StructField) {
if i < 0 || i >= len(t.fields) {
@@ -723,7 +783,7 @@
f.PkgPath = *p.pkgPath
}
if p.tag != nil {
- f.Tag = *p.tag
+ f.Tag = StructTag(*p.tag)
}
f.Offset = p.offset
f.Index = []int{i}
diff --git a/src/pkg/rpc/jsonrpc/all_test.go b/src/pkg/rpc/jsonrpc/all_test.go
index 02b9735..c1a9e8e 100644
--- a/src/pkg/rpc/jsonrpc/all_test.go
+++ b/src/pkg/rpc/jsonrpc/all_test.go
@@ -51,9 +51,9 @@
func TestServer(t *testing.T) {
type addResp struct {
- Id interface{} "id"
- Result Reply "result"
- Error interface{} "error"
+ Id interface{} `json:"id"`
+ Result Reply `json:"result"`
+ Error interface{} `json:"error"`
}
cli, srv := net.Pipe()
diff --git a/src/pkg/rpc/jsonrpc/client.go b/src/pkg/rpc/jsonrpc/client.go
index 57e977d..577d0ce 100644
--- a/src/pkg/rpc/jsonrpc/client.go
+++ b/src/pkg/rpc/jsonrpc/client.go
@@ -44,9 +44,9 @@
}
type clientRequest struct {
- Method string "method"
- Params [1]interface{} "params"
- Id uint64 "id"
+ Method string `json:"method"`
+ Params [1]interface{} `json:"params"`
+ Id uint64 `json:"id"`
}
func (c *clientCodec) WriteRequest(r *rpc.Request, param interface{}) os.Error {
@@ -60,9 +60,9 @@
}
type clientResponse struct {
- Id uint64 "id"
- Result *json.RawMessage "result"
- Error interface{} "error"
+ Id uint64 `json:"id"`
+ Result *json.RawMessage `json:"result"`
+ Error interface{} `json:"error"`
}
func (r *clientResponse) reset() {
diff --git a/src/pkg/rpc/jsonrpc/server.go b/src/pkg/rpc/jsonrpc/server.go
index 9c6b8b4..9801fdf 100644
--- a/src/pkg/rpc/jsonrpc/server.go
+++ b/src/pkg/rpc/jsonrpc/server.go
@@ -43,9 +43,9 @@
}
type serverRequest struct {
- Method string "method"
- Params *json.RawMessage "params"
- Id *json.RawMessage "id"
+ Method string `json:"method"`
+ Params *json.RawMessage `json:"params"`
+ Id *json.RawMessage `json:"id"`
}
func (r *serverRequest) reset() {
@@ -59,9 +59,9 @@
}
type serverResponse struct {
- Id *json.RawMessage "id"
- Result interface{} "result"
- Error interface{} "error"
+ Id *json.RawMessage `json:"id"`
+ Result interface{} `json:"result"`
+ Error interface{} `json:"error"`
}
func (c *serverCodec) ReadRequestHeader(r *rpc.Request) os.Error {
diff --git a/src/pkg/xml/embed_test.go b/src/pkg/xml/embed_test.go
index abfe781..ec7f478 100644
--- a/src/pkg/xml/embed_test.go
+++ b/src/pkg/xml/embed_test.go
@@ -12,14 +12,14 @@
}
type A struct {
- XMLName Name "http://domain a"
+ XMLName Name `xml:"http://domain a"`
C
B B
FieldA string
}
type B struct {
- XMLName Name "b"
+ XMLName Name `xml:"b"`
C
FieldB string
}
@@ -65,7 +65,7 @@
}
type A2 struct {
- XMLName Name "http://domain a"
+ XMLName Name `xml:"http://domain a"`
XY string
Xy string
}
@@ -92,7 +92,7 @@
}
type A3 struct {
- XMLName Name "http://domain a"
+ XMLName Name `xml:"http://domain a"`
xy string
}
@@ -108,7 +108,7 @@
}
type A4 struct {
- XMLName Name "http://domain a"
+ XMLName Name `xml:"http://domain a"`
Any string
}
diff --git a/src/pkg/xml/marshal.go b/src/pkg/xml/marshal.go
index d3a1f95..2ac03a9 100644
--- a/src/pkg/xml/marshal.go
+++ b/src/pkg/xml/marshal.go
@@ -108,7 +108,7 @@
xmlns := ""
if kind == reflect.Struct {
if f, ok := typ.FieldByName("XMLName"); ok {
- if tag := f.Tag; tag != "" {
+ if tag := f.Tag.Get("xml"); tag != "" {
if i := strings.Index(tag, " "); i >= 0 {
xmlns, name = tag[:i], tag[i+1:]
} else {
@@ -132,7 +132,7 @@
}
for i, n := 0, typ.NumField(); i < n; i++ {
- if f := typ.Field(i); f.PkgPath == "" && f.Tag == "attr" {
+ if f := typ.Field(i); f.PkgPath == "" && f.Tag.Get("xml") == "attr" {
if f.Type.Kind() == reflect.String {
if str := val.Field(i).String(); str != "" {
p.WriteByte(' ')
@@ -173,7 +173,7 @@
for i, n := 0, val.NumField(); i < n; i++ {
if f := typ.Field(i); f.Name != "XMLName" && f.PkgPath == "" {
name := f.Name
- switch tag := f.Tag; tag {
+ switch tag := f.Tag.Get("xml"); tag {
case "":
case "chardata":
if tk := f.Type.Kind(); tk == reflect.String {
diff --git a/src/pkg/xml/marshal_test.go b/src/pkg/xml/marshal_test.go
index 3408f6d..77b2e72 100644
--- a/src/pkg/xml/marshal_test.go
+++ b/src/pkg/xml/marshal_test.go
@@ -22,18 +22,18 @@
)
type Passenger struct {
- Name []string "name"
- Weight float32 "weight"
+ Name []string `xml:"name"`
+ Weight float32 `xml:"weight"`
}
type Ship struct {
- XMLName Name "spaceship"
+ XMLName Name `xml:"spaceship"`
- Name string "attr"
- Pilot string "attr"
- Drive DriveType "drive"
- Age uint "age"
- Passenger []*Passenger "passenger"
+ Name string `xml:"attr"`
+ Pilot string `xml:"attr"`
+ Drive DriveType `xml:"drive"`
+ Age uint `xml:"age"`
+ Passenger []*Passenger `xml:"passenger"`
secret string
}
@@ -46,22 +46,22 @@
type NamedType string
type Port struct {
- XMLName Name "port"
- Type string "attr"
- Number string "chardata"
+ XMLName Name `xml:"port"`
+ Type string `xml:"attr"`
+ Number string `xml:"chardata"`
}
type Domain struct {
- XMLName Name "domain"
- Country string "attr"
- Name []byte "chardata"
+ XMLName Name `xml:"domain"`
+ Country string `xml:"attr"`
+ Name []byte `xml:"chardata"`
}
type SecretAgent struct {
- XMLName Name "agent"
- Handle string "attr"
+ XMLName Name `xml:"agent"`
+ Handle string `xml:"attr"`
Identity string
- Obfuscate string "innerxml"
+ Obfuscate string `xml:"innerxml"`
}
var nilStruct *Ship
diff --git a/src/pkg/xml/read.go b/src/pkg/xml/read.go
index 427c311..786b69f 100644
--- a/src/pkg/xml/read.go
+++ b/src/pkg/xml/read.go
@@ -31,16 +31,16 @@
// For example, given these definitions:
//
// type Email struct {
-// Where string "attr"
+// Where string `xml:"attr"`
// Addr string
// }
//
// type Result struct {
-// XMLName xml.Name "result"
+// XMLName xml.Name `xml:"result"`
// Name string
// Phone string
// Email []Email
-// Groups []string "group>value"
+// Groups []string `xml:"group>value"`
// }
//
// result := Result{Name: "name", Phone: "phone", Email: nil}
@@ -79,11 +79,13 @@
// Groups was assigned considering the element path provided in the
// field tag.
//
-// Because Unmarshal uses the reflect package, it can only
-// assign to upper case fields. Unmarshal uses a case-insensitive
+// Because Unmarshal uses the reflect package, it can only assign
+// to exported (upper case) fields. Unmarshal uses a case-insensitive
// comparison to match XML element names to struct field names.
//
-// Unmarshal maps an XML element to a struct using the following rules:
+// Unmarshal maps an XML element to a struct using the following rules.
+// In the rules, the tag of a field refers to the value associated with the
+// key 'xml' in the struct field's tag (see the example above).
//
// * If the struct has a field of type []byte or string with tag "innerxml",
// Unmarshal accumulates the raw XML nested inside the element
@@ -92,9 +94,9 @@
// * If the struct has a field named XMLName of type xml.Name,
// Unmarshal records the element name in that field.
//
-// * If the XMLName field has an associated tag string of the form
-// "tag" or "namespace-URL tag", the XML element must have
-// the given tag (and, optionally, name space) or else Unmarshal
+// * If the XMLName field has an associated tag of the form
+// "name" or "namespace-URL name", the XML element must have
+// the given name (and, optionally, name space) or else Unmarshal
// returns an error.
//
// * If the XML element has an attribute whose name matches a
@@ -112,14 +114,14 @@
// field, the comments are discarded.
//
// * If the XML element contains a sub-element whose name matches
-// the prefix of a struct field tag formatted as "a>b>c", unmarshal
+// the prefix of a tag formatted as "a>b>c", unmarshal
// will descend into the XML structure looking for elements with the
// given names, and will map the innermost elements to that struct field.
-// A struct field tag starting with ">" is equivalent to one starting
+// A tag starting with ">" is equivalent to one starting
// with the field name followed by ">".
//
// * If the XML element contains a sub-element whose name
-// matches a struct field whose tag is neither "attr" nor "chardata",
+// matches a field whose tag is neither "attr" nor "chardata",
// Unmarshal maps the sub-element to that struct field.
// Otherwise, if the struct has a field named Any, unmarshal
// maps the sub-element to that struct field.
@@ -297,8 +299,7 @@
// Assign name.
if f, ok := typ.FieldByName("XMLName"); ok {
// Validate element name.
- if f.Tag != "" {
- tag := f.Tag
+ if tag := f.Tag.Get("xml"); tag != "" {
ns := ""
i := strings.LastIndex(tag, " ")
if i >= 0 {
@@ -330,7 +331,7 @@
// Also, determine whether we need to save character data or comments.
for i, n := 0, typ.NumField(); i < n; i++ {
f := typ.Field(i)
- switch f.Tag {
+ switch f.Tag.Get("xml") {
case "attr":
strv := sv.FieldByIndex(f.Index)
// Look for attribute.
@@ -366,15 +367,15 @@
}
default:
- if strings.Contains(f.Tag, ">") {
+ if tag := f.Tag.Get("xml"); strings.Contains(tag, ">") {
if fieldPaths == nil {
fieldPaths = make(map[string]pathInfo)
}
- path := strings.ToLower(f.Tag)
- if strings.HasPrefix(f.Tag, ">") {
+ path := strings.ToLower(tag)
+ if strings.HasPrefix(tag, ">") {
path = strings.ToLower(f.Name) + path
}
- if strings.HasSuffix(f.Tag, ">") {
+ if strings.HasSuffix(tag, ">") {
path = path[:len(path)-1]
}
err := addFieldPath(sv, fieldPaths, path, f.Index)
@@ -574,7 +575,7 @@
t := sv.Type()
f1 := t.FieldByIndex(idx1)
f2 := t.FieldByIndex(idx2)
- return &TagPathError{t, f1.Name, f1.Tag, f2.Name, f2.Tag}
+ return &TagPathError{t, f1.Name, f1.Tag.Get("xml"), f2.Name, f2.Tag.Get("xml")}
}
// unmarshalPaths walks down an XML structure looking for
diff --git a/src/pkg/xml/read_test.go b/src/pkg/xml/read_test.go
index e07cb15..2126da3 100644
--- a/src/pkg/xml/read_test.go
+++ b/src/pkg/xml/read_test.go
@@ -78,7 +78,7 @@
</summary></entry></feed> `
type Feed struct {
- XMLName Name "http://www.w3.org/2005/Atom feed"
+ XMLName Name `xml:"http://www.w3.org/2005/Atom feed"`
Title string
Id string
Link []Link
@@ -97,20 +97,20 @@
}
type Link struct {
- Rel string "attr"
- Href string "attr"
+ Rel string `xml:"attr"`
+ Href string `xml:"attr"`
}
type Person struct {
Name string
URI string
Email string
- InnerXML string "innerxml"
+ InnerXML string `xml:"innerxml"`
}
type Text struct {
- Type string "attr"
- Body string "chardata"
+ Type string `xml:"attr"`
+ Body string `xml:"chardata"`
}
type Time string
@@ -255,18 +255,18 @@
}
type PathTestA struct {
- Items []PathTestItem ">item1"
+ Items []PathTestItem `xml:">item1"`
Before, After string
}
type PathTestB struct {
- Other []PathTestItem "items>Item1"
+ Other []PathTestItem `xml:"items>Item1"`
Before, After string
}
type PathTestC struct {
- Values1 []string "items>item1>value"
- Values2 []string "items>item2>value"
+ Values1 []string `xml:"items>item1>value"`
+ Values2 []string `xml:"items>item2>value"`
Before, After string
}
@@ -275,7 +275,7 @@
}
type PathTestD struct {
- Other PathTestSet "items>"
+ Other PathTestSet `xml:"items>"`
Before, After string
}
@@ -299,15 +299,15 @@
}
type BadPathTestA struct {
- First string "items>item1"
- Other string "items>item2"
- Second string "items>"
+ First string `xml:"items>item1"`
+ Other string `xml:"items>item2"`
+ Second string `xml:"items>"`
}
type BadPathTestB struct {
- Other string "items>item2>value"
- First string "items>item1"
- Second string "items>item1>value"
+ Other string `xml:"items>item2>value"`
+ First string `xml:"items>item1"`
+ Second string `xml:"items>item1>value"`
}
var badPathTests = []struct {
@@ -342,13 +342,13 @@
}
type Test1 struct {
- Int int "attr"
- Float float64 "attr"
- Uint8 uint8 "attr"
+ Int int `xml:"attr"`
+ Float float64 `xml:"attr"`
+ Uint8 uint8 `xml:"attr"`
}
type Test2 struct {
- Bool bool "attr"
+ Bool bool `xml:"attr"`
}
const attrString = `
