encoding/json: inconsistent handling of keys with spaces

[rsc]

---------- Forwarded message ----------
From:  <billkatz@gmail.com>
Date: Mon, Jul 16, 2012 at 2:19 PM
Subject: [golang-dev] JSON key names with spaces get decoded properly but encoded
incorrectly
To: golang-dev@googlegroups.com


I've run into a snag using JSON keys with spaces in the encoding/json package.  

An example:

type Message struct {
    Name string `json:"myName"`
    Number int `json:"my number"`
}

Decodes work properly, correctly parsing a JSON string for something like:

{"myName": "Ed", "my number": 42}

But when encoding, json.Marshall will output:

{"myName": "Ed", "Number": 42}

Seems like any spaces in key name will cause encoding to drop back to the struct's field
name instead of the tag value.  I assume this is not by design and a patch is desired?

[gopherbot]

Comment 1 by billkatz:

It looks like JSON tag values don't compose naturally, which makes it unintuitive.
For example:
type SharedFields struct {
   Name string `json:"myName"`
   Number int `json:"my number"`
}
type Foo struct {
   SharedFields
   fooName string `json:"foo name"`
}
type Moo struct {
   SharedFields
   mooName string `json:"moo name"`
}
Here, both Moo and Foo would not be able to properly decode fields that were obtained
through composition.

[rsc]

Comment 2:

Re comment #1, I think that's a separate issue (anonymous fields, issue #3069).
Note, by the way, that fooName and mooName are unexported so ignored by the package no
matter what.

[rsc]

Comment 4:

Labels changed: added go1.1.

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Comment 5:

Labels changed: added size-m.

[rsc]

Comment 6:

Labels changed: added suggested.

[rsc]

Comment 7:

This issue was closed by revision 475f3df.

Status changed to Fixed.