Parse nim based jupyter notebook into a sort of literate nim, markdown goes into documentation blocks and code is kept

ipynb2nim.nim

import os,json,strutils

## TODO:
# - check input file type
# - a parser for markdown->html

let arguments = commandLineParams() # [0] should always be the input file
var nbf = arguments[0].readFile
var outfile :string 

if arguments.len>1 and arguments[1]=="into":
  outfile = arguments[2]
else:
  outfile = "out.nim"

var nbjson = parseJson(nbf) # parse the notebook as json 
var cnt : string = "" # content of the final file

proc jsonArrToStr(j:JsonNode):string # forward declaration, accumulate a JsonArray into a string

for cell in nbjson["cells"]:
  var ct = cell["cell_type"].str 
  if (ct == "markdown"):
    var src = cell["source"].jsonArrToStr
    cnt&= ("\n##[" & src & "]##\n")
  elif (ct=="code"):
    var src = cell["source"].jsonArrToStr
    cnt&=("\n"&src&"\n")

writefile(outfile, cnt)


proc jsonArrToStr(j:JsonNode):string =
  result = ""
  for e in j:
    result&=e.str