diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/retab.sml | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/tools/retab.sml b/tools/retab.sml new file mode 100644 index 00000000..b374eff2 --- /dev/null +++ b/tools/retab.sml @@ -0,0 +1,83 @@ +fun width (#"\t", i) = let val m = i mod 8 in if m = 0 then 8 else m end + | width (c, i) = 1 + +fun encode_width (offset) (l) = + let fun expand ([], i) = [] + | expand (c::tl, i) = let val w = width (c, i) + in (c, i, i + w) :: expand (tl, i + w) + end + in expand (l, offset) + end + +fun strip_blanks (#" "::tl) = strip_blanks (tl) + | strip_blanks (#"\t"::tl) = strip_blanks (tl) + | strip_blanks (#"\n"::tl) = strip_blanks (tl) + | strip_blanks (#"\r"::tl) = strip_blanks (tl) + | strip_blanks (other) = other + +fun clean (s) = rev (strip_blanks (rev (strip_blanks (s)))) + +fun split_comma (#","::tl) = [#","] :: (split_comma (strip_blanks (tl))) + | split_comma ([]) = [] + | split_comma (h::tl) = (case split_comma (tl) of + [] => [[h]] + | (h'::tl) => (h::h')::tl + ) + +fun expand (l : char list list list, offset : int) : char list list list = + if List.all (null) (l) (* at the end of all rows *) + then l + else let fun splitlist ([]::tl) = let val (heads, tails) = splitlist (tl) + in ([]::heads, []::tails) + end + | splitlist ((hrow::tlrow)::tl) = let val (heads, tails) = splitlist (tl) + in (hrow::heads, tlrow::tails) + end + | splitlist ([]) = ([], []) + val (heads, tails) = splitlist (l) + val eheads = map (encode_width offset) heads + + fun last_offset [] = offset + | last_offset (cell) = let val (_, _, x)::_ = rev (cell) in x end + val desired_final_offset = foldl Int.max offset (map last_offset (eheads)) +(* + val () = print ("start offset = " ^ Int.toString (offset) ^ "\n") + val () = print ("FINAL OFFSET = " ^ Int.toString (desired_final_offset) ^ "\n") +*) + fun align (i) = ((i + 7) div 8) * 8 + val desired_final_offset = align(desired_final_offset) +(* + val () = print ("FINAL OFFSET (align) = " ^ Int.toString (desired_final_offset) ^ "\n") +*) + fun fill (offset) = if offset >= desired_final_offset + then [] + else #"\t" :: fill (align (offset - 7) + 8) + val fill = if List.all null tails + then fn _ => [] + else fill + fun tabexpand ([]) = fill (offset) + | tabexpand (cell) = let val (_, _, finalwidth)::_ = rev (cell) + fun strip (x, _, _) = x + in rev (fill (finalwidth) @ rev (map strip (cell))) + end + val expanded_heads = map tabexpand (eheads) + val expanded_tails = expand (tails, desired_final_offset) + in ListPair.map op:: (expanded_heads, expanded_tails) + end + +fun align_strings (s : string list) = map (implode o List.concat) (expand (map ((map clean) o split_comma o explode) s, 0)) + +(*val test = align_strings (["foo, bar, quux", "a,b", "0,01234567890,c"])*) + +fun println (s) = (print (s); + print "\n") + +fun read_input () = + case TextIO.inputLine (TextIO.stdIn) of + NONE => [] + | SOME s => s :: read_input () + +fun main (_, _) = app println (align_strings (read_input ())) + +val () = main ("", []) + |