jsonc

Jsonc is a simplified json format which allows comments and unquoted values delimited by whitespace. A jsonc formatted file can be unambiguously transformed to a json file. Comments will be stripped out and quotes added.

Any valid json is also a valid jsonc.

give it a try

Install

go get github.com/komkom/jsonc/...

Use

In Code

dec, _ := jsonc.NewDecoder(strings.NewReader(`{
  a : "jsonc file" // with comments
}`))

x := struct {
  Key string `json:"a"`
}{}

_ = dec.Decode(&x)
fmt.Printf("%v\n", x)

As CLI

Prints the formatted jsonc file.

jsonc < somefile.jsonc 

Prints the minified json.

jsonc -m < somefile.jsonc 

Syntax

Here is a first attempt to formalize the jsonc syntax in ebnf.

document = type;

type = object | array | basicType;
basicType = nullSymbol | booleanSymbol | string | number;

object = "{" [{property [","] } property] "}";
property = string ":" type;

array = "[" [{type [","]} type] "]";

nullSymbol = "null";
booleanSymbol = "true" | "false";

string = stringToken | stringMultiline | jsonString;

stringToken = "a string containing only digits or letters.";
stringMultiline = "`" {stringSymbol lineBreak {lineBreak}} stringSymbol {lineBreak} "`";
jsonString = "a string as defined by json dot org including surrounding \" ";
lineBreak = "the line break character \n";

number = "a number as defined by json dot org";

Examples

// A jsonc example document
{
 owner:{
  name:`komkom`
  dob: /* just some random dob */ `1975-01-25T12:00:00-02:00`
 }

 database:{ // our live db
  server:`192.168.1.1`
  ports:[8001,8002,8003]
  connectionMax:5000
  enabled:true
 }

 servers:{ // a server
  alpha:{
   ip: /* is soon invalid */ `10.0.0.1`
   dc:`eqdc10`
  }
  
  beta:{
   ip:`10.0.0.2`
   dc:`eqdc10`
  }
 }
 
 clients:{
  data:[["gamma","delta"],[1,2]]
 }
 
 hosts:[alpha,omega]
}

{
 // Another example
 glossEntry:{
  id:SGML
  sortAs:SGML
  glossTerm:`Standard Generalized Markup language`
  acronym:SGML
  abbrev:`ISO 8879:1986`
  glossDef:{
   para:`A meta-markup language, used to create markup languages such as DocBook.`
   glossSeeAlso:[GML XML]
}}}

{
 // Another example
 popup:{
  menuitem:[
   {value:New,onclick:`CreateNewDoc()`}
   {value:Open,onclick:`OpenDoc()`}
   {value:Close,onclick:`CloseDoc()`}
  ]
}}

The formatting behaviour tries to mimic gofmt. Any suggestions, help, fixes welcome.