Opposite of astGenRepr

[iffycan]

Given a string with the results of an `astGenRepr` in it, how do I convert it 
back to a NimNode that matches the original?

Consider this:
    
    
    import macros
    
    macro astFor*(s:untyped):untyped =
      result = newLit(s.astGenRepr)
    
    macro start(): untyped =
      var x = astFor:
        proc foo() =
          echo "hi"
      
      echo "x: ", x
      var parsed = x.parseStmt()
      echo "parsed: ", parsed.astGenRepr
      # why is parsed.astGenRepr not the same as x?
    
    start
    
    
    Run

I'm looking for something like `parseStmt` that would make `parsed.astGenRepr` 
and `x` be the same. Instead, it produces this:
    
    
    x: nnkStmtList.newTree(
      nnkProcDef.newTree(
        newIdentNode("foo"),
        newEmptyNode(),
        newEmptyNode(),
        nnkFormalParams.newTree(
          newEmptyNode()
        ),
        newEmptyNode(),
        newEmptyNode(),
        nnkStmtList.newTree(
          nnkCommand.newTree(
            newIdentNode("echo"),
            newLit("hi")
          )
        )
      )
    )
    parsed: nnkStmtList.newTree(
      nnkCall.newTree(
        nnkDotExpr.newTree(
          newIdentNode("nnkStmtList"),
          newIdentNode("newTree")
        ),
        nnkCall.newTree(
          nnkDotExpr.newTree(
            newIdentNode("nnkProcDef"),
            newIdentNode("newTree")
          ),
          nnkCall.newTree(
            newIdentNode("newIdentNode"),
            newLit("foo")
          ),
          nnkCall.newTree(
            newIdentNode("newEmptyNode")
          ),
          nnkCall.newTree(
            newIdentNode("newEmptyNode")
          ),
          nnkCall.newTree(
            nnkDotExpr.newTree(
              newIdentNode("nnkFormalParams"),
              newIdentNode("newTree")
            ),
            nnkCall.newTree(
              newIdentNode("newEmptyNode")
            )
          ),
          nnkCall.newTree(
            newIdentNode("newEmptyNode")
          ),
          nnkCall.newTree(
            newIdentNode("newEmptyNode")
          ),
          nnkCall.newTree(
            nnkDotExpr.newTree(
              newIdentNode("nnkStmtList"),
              newIdentNode("newTree")
            ),
            nnkCall.newTree(
              nnkDotExpr.newTree(
                newIdentNode("nnkCommand"),
                newIdentNode("newTree")
              ),
              nnkCall.newTree(
                newIdentNode("newIdentNode"),
                newLit("echo")
              ),
              nnkCall.newTree(
                newIdentNode("newLit"),
                newLit("hi")
              )
            )
          )
        )
      )
    )
    
    
    Run