pretty_json.nim

import strutils, json, os

proc cleanupWhitespace(s: string): string =
  ## Removes trailing whitespace and normalizes line endings to LF.
  result = newStringOfCap(s.len)
  var i = 0
  while i < s.len:
    if s[i] == ' ':
      var j = i+1
      while s[j] == ' ': inc j
      if s[j] == '\c':
        inc j
        if s[j] == '\L': inc j
        result.add '\L'
        i = j
      elif s[j] == '\L':
        result.add '\L'
        i = j+1
      else:
        result.add ' '
        inc i
    elif s[i] == '\c':
      inc i
      if s[i] == '\L': inc i
      result.add '\L'
    elif s[i] == '\L':
      result.add '\L'
      inc i
    else:
      result.add s[i]
      inc i
  if result[^1] != '\L':
    result.add '\L'

proc editJson() =
  var contents = parseFile("packages.json")
  doAssert contents.kind == JArray
  writeFile("packages.json", contents.pretty.cleanupWhitespace)

editJson()