Read from stdin

[sdmcallister]

Does it make sense (or does it already exist) to add the capability to cat a file to a NimData Program? Something like
cat datafile | mynimdataprogram
Granted a file like the one above exists, and could be handled with the existing procs. But there are also situations where you might be following a file that has new data regularly added and you may want to peridiocally show the result.

[bluenote10]

On first glance reading from stdin seems like a reasonable idea.

[sdmcallister]

I'm a bit of a noob so there is likely a better way, but I was getting this to work:

type
  StreamRowsDataFrame = ref object of DataFrame[string]
    hasHeader: bool

method iter*(df: StreamRowsDataFrame): (iterator(): string) =
  result = iterator(): string =
    if df.hasHeader:
      discard stdin.readLine()
    while not endOfFile(stdin):
      yield stdin.readLine()

proc fromStream*(dfc: DataFrameContext,
               hasHeader: bool = true): DataFrame[string] =

  result = StreamRowsDataFrame(
    hasHeader: hasHeader
  )

I'd like to eventually learn and contribute more.