X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;f=csv.ml;h=0b6e649f7446c22768b44a8b6338c0f60245b35c;hb=3a2b495714080c9f72b89cada8bc45b22768a059;hp=2a22bf983eef6e3e372b825de554e0e08eee65fe;hpb=ae6f56ba8e80a1c05aa076404dd14145b306780a;p=ocaml-csv.git

diff --git a/csv.ml b/csv.ml
index 2a22bf9..0b6e649 100644
--- a/csv.ml
+++ b/csv.ml
@@ -1,6 +1,6 @@
 (* csv.ml - comma separated values parser
  *
- * $Id: csv.ml,v 1.8 2006-02-15 13:25:58 rich Exp $
+ * $Id: csv.ml,v 1.14 2006-11-24 15:49:24 rich Exp $
  *)
 
 (* The format of CSV files:
@@ -40,6 +40,13 @@
  * subset of it into a matrix.
  *)
 
+open Printf
+
+(* Uncomment the next line to enable Extlib's List function.  These
+ * avoid stack overflows on really huge CSV files.
+ *)
+(*open ExtList*)
+
 type t = string list list
 
 exception Bad_CSV_file of string
@@ -171,10 +178,13 @@ let load_in ?separator chan =
   List.rev !csv
 
 let load ?separator filename =
-  let chan = open_in filename in
+  let chan, close =
+    match filename with
+    | "-" -> stdin, false
+    | filename -> open_in filename, true in
   let csv = load_in ?separator chan in
-  close_in chan;
-  csv 
+  if close then close_in chan;
+  csv
 
 let trim ?(top=true) ?(left=true) ?(right=true) ?(bottom=true) csv =
   let rec empty_row = function
@@ -265,6 +275,59 @@ let sub r c rows cols csv =
   let csv = set_columns cols csv in
   csv
 
+(* Compare two rows for semantic equality - ignoring any blank cells
+ * at the end of each row.
+ *)
+let rec compare_row (row1 : string list) row2 =
+  match row1, row2 with
+  | [], [] -> 0
+  | x :: xs, y :: ys ->
+      let c = compare x y in
+      if c <> 0 then c else compare_row xs ys
+  | "" :: xs , [] ->
+      compare_row xs []
+  | x :: xs, [] ->
+      1
+  | [], "" :: ys ->
+      compare_row [] ys
+  | [], y :: ys ->
+      -1
+
+(* Semantic equality for CSV files. *)
+let rec compare (csv1 : t) csv2 =
+  match csv1, csv2 with
+  | [], [] -> 0
+  | x :: xs, y :: ys ->
+      let c = compare_row x y in
+      if c <> 0 then c else compare xs ys
+  | x :: xs, [] ->
+      let c = compare_row x [] in
+      if c <> 0 then c else compare xs []
+  | [], y :: ys ->
+      let c = compare_row [] y in
+      if c <> 0 then c else compare [] ys
+
+(* Concatenate - arrange left to right. *)
+let rec concat = function
+  | [] -> []
+  | [csv] -> csv
+  | left_csv :: csvs ->
+      (* Concatenate the remaining CSV files. *)
+      let right_csv = concat csvs in
+
+      (* Set the height of the left and right CSVs to the same. *)
+      let nr_rows = max (lines left_csv) (lines right_csv) in
+      let left_csv = set_rows nr_rows left_csv in
+      let right_csv = set_rows nr_rows right_csv in
+
+      (* Square off the left CSV. *)
+      let left_csv = square left_csv in
+
+      (* Prepend the right CSV rows with the left CSV rows. *)
+      List.map (
+	fun (left_row, right_row) -> List.append left_row right_row
+      ) (List.combine left_csv right_csv)
+
 let to_array csv =
   Array.of_list (List.map Array.of_list csv)
 
@@ -337,18 +400,18 @@ let save_out_readable chan csv =
 
     match csv with
       | [] -> []
-      | r :: _ ->
-	  let n = List.length r in
-	  let lengths = List.map (List.map String.length) csv in
+      | row1 :: rest ->
+	  let lengths_row1 = List.map String.length row1 in
+	  let lengths_rest = List.map (List.map String.length) rest in
 	  let max2rows r1 r2 =
-	    let rp = List.combine r1 r2 in
+	    let rp =
+	      try List.combine r1 r2
+	      with
+		Invalid_argument "List.combine" ->
+		  failwith (sprintf "Csv.save_out_readable: internal error: length r1 = %d, length r2 = %d" (List.length r1) (List.length r2)) in
 	    List.map (fun ((a : int), (b : int)) -> max a b) rp
 	  in
-	  let rec repeat x = function
-	    | 0 -> []
-	    | i -> x :: repeat x (i-1)
-	  in
-	  List.fold_left max2rows (repeat 0 n) lengths in
+	  List.fold_left max2rows lengths_row1 lengths_rest in
 
   (* Print out each cell at the correct width. *)
   let rec repeat f = function
@@ -361,9 +424,17 @@ let save_out_readable chan csv =
 	output_string chan cell;
 	output_char chan '\n'
     | row ->				(* Other. *)
-	let row = List.combine widths row in
+	(* Pair up each cell with its max width. *)
+	let row =
+	  let rec loop = function
+	    | ([], _) -> []
+	    | (_, []) -> failwith "Csv.save_out_readable: internal error"
+	    | (cell :: cells, width :: widths) ->
+		(cell, width) :: loop (cells, widths)
+	  in
+	  loop (row, widths) in
 	List.iter (
-	  fun (width, cell) ->
+	  fun (cell, width) ->
 	    output_string chan cell;
 	    let n = String.length cell in
 	    repeat (fun () -> output_char chan ' ') (width - n + 1)