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How to read a file in SML line by line

I want to write a function that reads a text file line by line. ie, read the first line until EOL and then treat this as a string, and repeat this until the text ends. I have managed only this much till now:

fun read file = 
let val is = TextIO.openIn file
in
end
Solution

  • You can use TextIO.inputLine : instream -> string option for this. Using refs you can do something like

    let
  val stream = TextIO.openIn file
  val done = ref false
in
  while not (!done) do
    case TextIO.inputLine stream of
      SOME s => print s
    | NONE => done := true
end

    You can also use the functions in TextIO.StreamIO.