Csv.compare function.

diff --git a/csv.ml b/csv.ml
index 2a22bf9..efb1bc0 100644 (file)
--- 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 1.9 2006-02-23 15:24:25 rich Exp $
  *)
 
 (* The format of CSV files:
@@ -265,6 +265,38 @@ 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
+
 let to_array csv =
   Array.of_list (List.map Array.of_list csv)
 

diff --git a/csv.mli b/csv.mli
index baf9e5c..ef061e6 100644 (file)
--- a/csv.mli
+++ b/csv.mli
@@ -1,6 +1,6 @@
 (** csv.mli - comma separated values parser
   *
-  * $Id: csv.mli,v 1.7 2005-11-25 14:08:46 rich Exp $
+  * $Id: csv.mli,v 1.8 2006-02-23 15:24:25 rich Exp $
   *)
 
 type t = string list list
@@ -105,6 +105,13 @@ val sub : int -> int -> int -> int -> t -> t
   * The returned CSV will be square.
   *)
 
+val compare : t -> t -> int
+(** Compare two CSV files for equality, ignoring blank cells at the end
+  * of a row, and empty rows appended to one or the other.  This is
+  * "semantic" equality - roughly speaking, the two CSV files would
+  * look the same if opened in a spreadsheet program.
+  *)
+
 val to_array : t -> string array array
 val of_array : string array array -> t
 (** Convenience functions to convert to and from a matrix representation.

diff --git a/test.ml b/test.ml
index 2ab02ad..a8537a5 100644 (file)
--- a/test.ml
+++ b/test.ml
@@ -1,4 +1,4 @@
-(* $Id: test.ml,v 1.1 2003-12-17 16:05:08 rich Exp $ *)
+(* $Id: test.ml,v 1.2 2006-02-23 15:24:25 rich Exp $ *)
 
 open Printf
 open Csv
@@ -13,16 +13,17 @@ let do_testcsv filename expected =
     print expected;
     failwith "failed"
   )
+  else ()
 
-let testcsv1 =
+let () =
   do_testcsv
     "testcsv1.csv"
     [ [ "This is a test\nwith commas,,,,,\n\nand carriage returns." ] ]
-let testcsv2 =
+let () =
   do_testcsv
     "testcsv2.csv"
     [ [ "Normal field"; "Quoted field"; "Quoted field with \"\" quotes" ] ]
-let testcsv3 =
+let () =
   do_testcsv
     "testcsv3.csv"
     [ [ "" ];
@@ -30,23 +31,42 @@ let testcsv3 =
       [ ""; ""; "" ];
       [ ""; ""; ""; "" ];
       [ ""; ""; ""; ""; "" ] ]
-let testcsv4 =
+let () =
   do_testcsv
     "testcsv4.csv"
     []
-let testcsv5 =
+let () =
   do_testcsv
     "testcsv5.csv"
     [ [ "This is a test\nwith commas,,,,,\n\nand carriage returns.";
        "a second field"; "a third field" ];
       [ "a fourth field on a new line" ] ]
-let testcsv6 =
+let () =
   do_testcsv
     "testcsv6.csv"
     [ [ "This is a test\nwith commas,,,,,\n\nand carriage returns\nand \000";
        "a second field"; "a third field" ];
       [ "a fourth field on a new line" ] ]
 
+let () =
+  let csv1 = [ [ "a"; "b"; "c"; ""; "" ];
+              [ "f"; "g"; "h"; "i"; "" ];
+              [ "" ];
+              [ ] ] in
+  let csv2 = trim ~top:false ~left:false ~right:true ~bottom:true csv1 in
+  assert (compare csv1 csv2 = 0)
+let () =
+  let csv1 = [ [ "a"; "b"; "c"; ""; "" ];
+              [ "f"; "g"; "h"; "i"; "" ];
+              [ "" ];
+              [ ] ] in
+  let csv2 = [ [ "a"; "b"; "c"; "d"; "" ];
+              [ "f"; "g"; "h"; "i"; "" ];
+              [ "" ];
+              [ ] ] in
+  assert (compare csv1 csv2 < 0)
+
+
 ;;
 
 print_endline "All tests succeeded."