Implemented:

  Csv.square
  Csv.is_square
  Csv.set_columns
  Csv.set_rows
  Csv.set_size
  Csv.sub
  Csv.to_array
  Csv.of_array

diff --git a/csv.ml b/csv.ml
index 1c0ae62..0ff0371 100644 (file)
--- a/csv.ml
+++ b/csv.ml
@@ -1,6 +1,6 @@
 (* csv.ml - comma separated values parser
  *
- * $Id: csv.ml,v 1.6 2005-08-13 10:10:31 rich Exp $
+ * $Id: csv.ml,v 1.7 2005-11-25 14:06:58 rich Exp $
  *)
 
 (* The format of CSV files:
@@ -49,6 +49,15 @@ let rec dropwhile f = function
   | x :: xs when f x -> dropwhile f xs
   | xs -> xs
 
+(* from extlib: *)
+let rec drop n = function
+  | _ :: l when n > 0 -> drop (n-1) l
+  | l -> l
+
+let rec take n = function
+  | x :: xs when n > 0 -> x :: take (pred n) xs
+  | _ -> []
+
 let lines = List.length
 
 let columns csv =
@@ -221,6 +230,47 @@ let square csv =
       List.rev row
   ) csv
 
+let is_square csv =
+  let columns = columns csv in
+  List.for_all (fun row -> List.length row = columns) csv
+
+let rec set_columns cols = function
+  | [] -> []
+  | r :: rs ->
+      let rec loop i cells =
+       if i < cols then (
+         match cells with
+         | [] -> "" :: loop (succ i) []
+         | c :: cs -> c :: loop (succ i) cs
+       )
+       else []
+      in
+      loop 0 r :: set_columns cols rs
+
+let rec set_rows rows csv =
+  if rows > 0 then (
+    match csv with
+    | [] -> [] :: set_rows (pred rows) []
+    | r :: rs -> r :: set_rows (pred rows) rs
+  )
+  else []
+
+let set_size rows cols csv =
+  set_columns cols (set_rows rows csv)
+
+let sub r c rows cols csv =
+  let csv = drop r csv in
+  let csv = List.map (drop c) csv in
+  let csv = set_rows rows csv in
+  let csv = set_columns cols csv in
+  csv
+
+let to_array csv =
+  Array.of_list (List.map Array.of_list csv)
+
+let of_array csv =
+  List.map Array.to_list (Array.to_list csv)
+
 let associate header data =
   let nr_cols = List.length header in
   let rec trunc = function

diff --git a/csv.mli b/csv.mli
index b35e480..a8e570d 100644 (file)
--- a/csv.mli
+++ b/csv.mli
@@ -1,6 +1,6 @@
 (** csv.mli - comma separated values parser
   *
-  * $Id: csv.mli,v 1.5 2005-05-24 13:52:50 rich Exp $
+  * $Id: csv.mli,v 1.6 2005-11-25 14:06:58 rich Exp $
   *)
 
 type t = string list list
@@ -72,6 +72,46 @@ val square : t -> t
   * {!columns}.
   *)
 
+val is_square : t -> bool
+(** Return true iff the CSV is "square" (actually rectangular).  This
+  * means that each row has the same number of cells.
+  *)
+
+val set_columns : int -> t -> t
+(** [set_columns cols csv] makes the CSV data square by forcing the width
+  * to the given number of [cols].  Any short rows are padded with blank
+  * cells.  Any long rows are truncated.
+  *)
+
+val set_rows : int -> t -> t
+(** [set_rows rows csv] makes the CSV data have exactly [rows] rows
+  * by adding empty rows or truncating rows as necessary.
+  *
+  * Note that [set_rows] does not make the CSV square.  If you want it
+  * to be square, call either {!Csv.square} or {!Csv.set_columns} after.
+  *)
+
+val set_size : int -> int -> t -> t
+(** [set_size rows cols csv] makes the CSV data square by forcing the
+  * size to [rows * cols], adding blank cells or truncating as necessary.
+  * It is the same as calling [set_columns cols (set_rows rows csv)]
+  *)
+
+val sub : int -> int -> int -> int -> t -> t
+(** [sub r c rows cols csv] returns a subset of [csv].  The subset is
+  * defined as having top left corner at row [r], column [c] (counting
+  * from [0]) and being [rows] deep and [cols] wide.
+  *
+  * The returned CSV will be square.
+  *)
+
+val to_array : t -> string array array
+val of_array : string array array -> t
+(** Convenience functions to convert to and from a matrix representation.
+  * [to_array] will produce a ragged matrix (not all rows will have the
+  * same length) unless you call {!Csv.square} first.
+  *)
+
 val associate : string list -> t -> (string * string) list list
 (** [associate header data] takes a block of data and converts each
   * row in turn into an assoc list which maps column header to data cell.

diff --git a/csvtool.ml b/csvtool.ml
index 0b82a4b..1cee449 100644 (file)
--- a/csvtool.ml
+++ b/csvtool.ml
@@ -1,5 +1,5 @@
 (* Handy tool for managing CSV files.
- * $Id: csvtool.ml,v 1.1 2005-05-24 13:52:50 rich Exp $
+ * $Id: csvtool.ml,v 1.2 2005-11-25 14:06:58 rich Exp $
  *)
 
 open Printf
@@ -42,6 +42,21 @@ let cmd_height ~csv ~chan () =
 let cmd_readable ~csv ~chan () =
   save_out_readable chan csv
 
+let cmd_square ~separator ~csv ~chan () =
+  let csv = square csv in
+  save_out ~separator chan csv
+
+let cmd_sub ~separator ~csv ~chan args =
+  let r, c, rows, cols =
+    match args with
+    | [ r; c; rows; cols ] ->
+       int_of_string r, int_of_string c,
+       int_of_string rows, int_of_string cols
+    | _ ->
+       failwith "unknown arguments to 'sub' command" in
+  let csv = sub r c rows cols csv in
+  save_out ~separator chan csv
+
 (* Process the arguments. *)
 let usage =
   "csvtool - Copyright (C) 2005 Richard W.M. Jones, Merjis Ltd.
@@ -70,6 +85,13 @@ Commands:
   readable
     Print the input CSV in a readable format.
 
+  square
+    Make the CSV square, so all rows have the same length.
+
+  sub r c rows cols
+    Take a square subset of the CSV, top left at row r, column c (counting
+    from 0), which is rows deep and cols wide.
+
 Input and output files:
   csvtool normally processes its input from stdin and writes its output
   to stdout.  Use the -i and -o options to override this behaviour.
@@ -144,6 +166,10 @@ let () =
         cmd_height ~csv:input ~chan ()
      | "readable" ->
         cmd_readable ~csv:input ~chan ()
+     | "square" ->
+        cmd_square ~separator:output_sep ~csv:input ~chan ()
+     | "sub" ->
+        cmd_sub ~separator:output_sep ~csv:input ~chan args
      | _ -> prerr_endline (Sys.executable_name ^ " --help for usage")
   );