Json stuff

[def-]

Some people said it's a pain to generate JSON in Nim. Since Nim is statically typed you can't just write

var j = [{"name": "John", "age": 30}, {"name": "Susan", "age": 31}]

Instead you have to add a % everywhere to convert to JSON:

var j = %[%{"name": %"John", "age": %30}, %{"name": %"Susan", "age": %31}]

That's annoying if you just want to paste some actual JSON into your source and set a few variables. The new %* macro automatically adds % where necessary. So you can now write:

var j = %*[{"name": "John", "age": 30}, {"name": "Susan", "age": 31}]

Or even with pretty indentation of your choice:

var j2 = %*
  [
    {
      "name": "John",
      "age": 30
    },
    {
      "name": "Susan",
      "age": 31
    }
  ]
echo j2

var name = "John"
let herAge = 30
const hisAge = 31

var j3 = %*
  [ { "name": name
    , "age": herAge
    }
  , { "name": "Susan"
    , "age": hisAge
    }
  ]
echo j3

[Araq]

Funny, I thought we already had that!

[gradha]

Funny, I also thought we had better docs for this module!

[def-]

Nice work on the documentation @gradha .

[Varriount]

@def- You still have some debugging echo's left in the new macro.

[Araq]

@gradha Sorry, I had too many merge conflicts with these better docs, so I deliberately lost them. Also, IMHO they were too verbose and you copied stuff like how the 'assert' works to the description of every accessor. You should have documented that once in the module's top level comment.

[Varriount]

So what's the final verdict on this? Does another procedure already exists that does the same thing @def- 's macro does?

[def-]

@Varriount: A procedure couldn't do this and I don't see any macros or templates in the json module.

[flaviut]

Does this need to be an operator? I'd prefer a regular word; jsonify comes to mind.

Brevity isn't really important here since only one call would be needed for an entire JSON object.

[def-]

I guess it doesn't have to be. I just like %* because it applies % everywhere.

[Araq]

I like %* better than jsonify.

[dom96]

👍 for %*

[dustinlacewell]

Putting my vote in for jsonify

[Araq]

The convention is to use PNimrodNode for .compileTime procs.

[def-]

Speaking of which, can we not distinguish between '%*' and '%'? That makes it much easier to use IMHO. Overloading resolution should be able to handle that, right?

That might be nice, but doesn't work. The compiler complains because it tries to parse these as an array instead of resorting to the more general % macro on failure:

  var j = % [{"name": "John", "age": 30}, {"name": "Susan", "age": 31}]

lib/pure/json.nim(1133, 35) Error: type mismatch: got (tuple[string, int]) but expected 'tuple[string, string]'