Block comments

[Timmmm]

You need to specify how block comments nest, what happens if you start a block comment in a string, etc.

[hattesen]

If the specification covers where in the JSON structure block-comments are allowed, I don't believe nesting will be ambiguous.

e.g.

Block comment syntax in strings

Block comments syntax within JSON keys/value strings are NOT parsed as a comment, but as part of the key/value.

{
    "name": "John Doe /* NOT a comment */",
    "age /* NOT a comment */": 30
}

**Where in the JSON syntax may block comments appear? **

It needs to be clarified where block comments may appear within the JSON syntax...

/*LEADING*/
{ 
    /*PRE-KEY*/ "name" /*POST-KEY*/ : /*PRE-VALUE*/ "John Doe" /*POST-VALUE*/,
    "age": 30
}
/*TRAILING*/

** Nesting **

It needs to be explicitly clarified that nesting of block comments is NOT supported.

AFAIK nesting of block comments is NOT supported by any language using the /* comment */ format, other than Swift.

{ 
/* OUTER start
  /* NESTED block comments are not supported.
      OUTER block comment will end here --> */
  OUTER end
*/
    "name": "John Doe",
    "age": 30
}

[DecimalTurn]

Exactly, there is no intention to support nested comments here as it's not a common practice and the node-jsonc-parser doesn't support them. We could include something similar to https://github.com/stephenberry/JSONC#block-comments in the spec.

If we really want to be exhaustive, we could clarify that comments can't appear inside any of the following types: number, string, true, false, or null.

Basically, in terms of railroad diagram, we would replace :

With:

graph LR
    A@{ shape: sm-circ } 
	
	SI@{ shape: sm-circ, label: "token start" } 
	EI@{ shape: sm-circ, label: "token end" } 

    E@{ shape: framed-circle, label: "Stop" }

	A --> SI
	SI --> B[Space]
    SI--> C[linefeed]
    SI --> D[carriage return]
	SI --> H[horizontal tab]
	SI --> F[inline comment]
	SI --> G[block comment]
	

	A --> E
	B --> EI
	C --> EI
	D --> EI
	F --> EI
	G --> EI
	H --> EI

	EI --> SI

	EI --> E	

Loading

What might be non-obvious at first it that inline comments are valid everywhere a block comment would also be. For instance, the following would still be valid JSONC (node-jsonc-parser supports it):

{
  "version": //test
  "0.2.0"
}