Nim macro play

macro.nim

import macros, strutils


macro route(path: untyped, s: untyped): untyped =
  let pathParts = path.strVal().split("/")
  let functionName = pathParts[1]
  var pathVars: seq[string] = @[]

  for pathPart in pathParts:
    if pathPart.startsWith("{"):
      pathVars.add(pathPart.multiReplace(("{", "") , ("}", "")))

  if pathVars.len() > 0:
    var procStatements = newStmtList()

    var procDef = newNimNode(nnkProcDef)
    procDef.add(newIdentNode(functionName))
    procDef.add(newEmptyNode())
    procDef.add(newEmptyNode())

    var params = newNimNode(nnkFormalParams)
    params.add(newEmptyNode())

    for pathVar in pathVars:
      var idNode = newNimNode(nnkIdentDefs)
      idNode.add(newIdentNode(pathVar))
      idNode.add(newIdentNode("string"))
      idNode.add(newEmptyNode())
      params.add(idNode)

    procDef.add(params)
    procDef.add(newEmptyNode())
    procDef.add(newEmptyNode())

    procDef.add(s)

    procStatements.add(procDef)

    result = procStatements

  else:
    result = quote do:
      proc route_proc() = 
        `s`


route "/root/{param_1}/{param_2}/after":
  let a = 1 + 1
  echo a, param_1, param_2

root("first", "second")