/// Reverses the columns in a single line based on the delimiter regex pattern.
/// Splits the line using the regex with capturing groups to preserve delimiters, reverses the columns, and joins back with reversed delimiters.
let private reverseColumnsLine (line: string) (delim: string) : string =
if String.IsNullOrEmpty line then ""
else
let pattern = "(" + delim + ")"
let regex = Regex(pattern)
let parts = regex.Split(line)
if parts.Length = 1 then line
else
let columns = [ for i in 0 .. 2 .. parts.Length - 1 -> parts.[i] ]
let delims = if parts.Length > 1 then [ for i in 1 .. 2 .. parts.Length - 2 -> parts.[i] ] else []
let rev_columns = List.rev columns
let rev_delims = List.rev delims
let sb = System.Text.StringBuilder()
for i in 0 .. rev_columns.Length - 1 do
sb.Append(rev_columns.[i]) |> ignore
if i < rev_columns.Length - 1 then
sb.Append(rev_delims.[i]) |> ignore
sb.ToString()
/// Pure function to process a single line for app2 (initially reverses columns).
let processAppDataLine (line: string) (delim: string) : string =
reverseColumnsLine line delim
/// Pure function to process a single line for app2-test (initially reverses columns).
let processAppTestDataLine (line: string) (delim: string) : string =
reverseColumnsLine line delim
I think I can live-link into specific lines of code. Will check that out later.