55 lines
1.6 KiB
OCaml
55 lines
1.6 KiB
OCaml
#load "str.cma"
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open Str
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let input = "\
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Given$a$text$file$of$many$lines,$where$fields$within$a$line$
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are$delineated$by$a$single$'dollar'$character,$write$a$program
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that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
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column$are$separated$by$at$least$one$space.
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Further,$allow$for$each$word$in$a$column$to$be$either$left$
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justified,$right$justified,$or$center$justified$within$its$column."
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let () =
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let lines = split (regexp_string "\n") input in
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let fields_l = List.map (split (regexp_string "$")) lines in
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let fields_l = List.map Array.of_list fields_l in
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let n = (* number of columns *)
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List.fold_left
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(fun n fields -> max n (Array.length fields))
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0 fields_l
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in
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let pads = Array.make n 0 in
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List.iter (
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(* calculate the max padding for each column *)
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Array.iteri
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(fun i word -> pads.(i) <- max pads.(i) (String.length word))
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) fields_l;
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let print f =
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List.iter (fun fields ->
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Array.iteri (fun i word ->
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f word (pads.(i) - (String.length word))
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) fields;
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print_newline()
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) fields_l;
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in
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(* left column-aligned output *)
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print (fun word pad ->
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let spaces = String.make pad ' ' in
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Printf.printf "%s%s " word spaces);
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(* right column-aligned output *)
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print (fun word pad ->
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let spaces = String.make pad ' ' in
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Printf.printf "%s%s " spaces word);
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(* center column-aligned output *)
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print (fun word pad ->
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let pad1 = pad / 2 in
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let pad2 = pad - pad1 in
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let sp1 = String.make pad1 ' ' in
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let sp2 = String.make pad2 ' ' in
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Printf.printf "%s%s%s " sp1 word sp2);
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;;
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