How do you read the lines of a text file…

Learning
5

@K_N thanks to @nojb’s work, these mundane tasks finally get bearable with the upcoming 4.14 Stdlib.

For example:

let lines file =
  let contents = In_channel.with_open_bin file In_channel.input_all in
  String.split_on_char '\n' contents

Or to support the widespread tool convention that filename - means stdin:

let lines file =
  let contents = match file with
  | "-" -> In_channel.input_all In_channel.stdin
  | file -> In_channel.with_open_bin file In_channel.input_all
  in
  String.split_on_char '\n' contents

And for writing:

let write_lines file lines =
  let output_lines oc = output_string oc (String.concat "\n" lines) in
  Out_channel.with_open_bin file output_lines

let write_lines file lines =
  let output_lines oc = output_string oc (String.concat "\n" lines) in
  match file with
  | "-" -> output_lines Out_channel.stdout
  | file -> Out_channel.with_open_bin file output_lines
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