update json comments

R=r
DELTA=16  (4 added, 2 deleted, 10 changed)
OCL=35320
CL=35331

diff --git a/src/pkg/json/struct.go b/src/pkg/json/struct.go
index 680a5af4bec62bf45c9e9b5d4bcdc732b3c8ef23..250fe7da2a5a4d5d715397703f1e0dbb6628aa71 100644 (file)
--- a/src/pkg/json/struct.go
+++ b/src/pkg/json/struct.go
@@ -179,10 +179,8 @@ func (b *_StructBuilder) Key(k string) Builder {
        }
        if v, ok := reflect.Indirect(b.val).(*reflect.StructValue); ok {
                t := v.Type().(*reflect.StructType);
-               if field, ok := t.FieldByName(k); ok {
-                       return &_StructBuilder{ v.FieldByIndex(field.Index) }
-               }
-               // Again, case-insensitive.
+               // Case-insensitive field lookup.
+               k = strings.ToLower(k);
                for i := 0; i < t.NumField(); i++ {
                        if strings.ToLower(t.Field(i).Name) == k {
                                return &_StructBuilder{ v.Field(i) }
@@ -194,21 +192,21 @@ func (b *_StructBuilder) Key(k string) Builder {
 
 // Unmarshal parses the JSON syntax string s and fills in
 // an arbitrary struct or array pointed at by val.
-// It uses the reflection library to assign to fields
+// It uses the reflect package to assign to fields
 // and arrays embedded in val.  Well-formed data that does not fit
 // into the struct is discarded.
 //
-// For example, given the following definitions:
+// For example, given these definitions:
 //
 //     type Email struct {
-//             where string;
-//             addr string;
+//             Where string;
+//             Addr string;
 //     }
 //
 //     type Result struct {
-//             name string;
-//             phone string;
-//             emails []Email
+//             Name string;
+//             Phone string;
+//             Email []Email
 //     }
 //
 //     var r = Result{ "name", "phone", nil }
@@ -241,9 +239,13 @@ func (b *_StructBuilder) Key(k string) Builder {
 //             }
 //     }
 //
-// Note that the field r.phone has not been modified and
+// Note that the field r.Phone has not been modified and
 // that the JSON field "address" was discarded.
 //
+// Because Unmarshal uses the reflect package, it can only
+// assign to upper case fields.  Unmarshal uses a case-insensitive
+// comparison to match JSON field names to struct field names.
+//
 // On success, Unmarshal returns with ok set to true.
 // On a syntax error, it returns with ok set to false and errtok
 // set to the offending token.