Soundex/OCaml: Difference between revisions
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(a soundex version that can switch the language) |
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Here is a version with very few changes, which allows choosing different languages ('''en''' for English, '''fr''' for French) of type '''lang''', the definition of this type will be hidden in the interface.
<
type lang = char -> string
let en = function
Line 49 ⟶ 50:
match dbl [] (List.rev !cl) with
| c::rem -> (String.make 1 c) ^ (soundex_aux lang rem)
| [] -> invalid_arg "soundex"
</syntaxhighlight>
in the interface as the definition of the type '''lang''' is hidden we can use it easily as a classic parameter:
<syntaxhighlight lang
type lang
val en : lang
Line 71 ⟶ 64:
type lang_set = (int * char list) list
val make_lang : lang_set -> lang
</syntaxhighlight>
The '''lang''' parameter for the '''soundex''' function is optional, if omited the english set is used.
Line 81 ⟶ 75:
Test that the function make_lang provide the same results:
<syntaxhighlight lang
open Soundex
let tests = [
Line 109 ⟶ 104:
let status = if code1 = code2 then "OK " else "Arg" in
Printf.printf " \"%s\" \t %s %s %s\n" word code1 code2 status
) tests
</syntaxhighlight>
We can run this test file with: <code>ocaml soundex.cmo test.ml</code>
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Latest revision as of 08:56, 21 July 2023
Here is a version with very few changes, which allows choosing different languages (en for English, fr for French) of type lang, the definition of this type will be hidden in the interface.
type lang = char -> string
let en = function
| 'B' | 'F' | 'P' | 'V' -> "1"
| 'C' | 'G' | 'J' | 'K' | 'Q' | 'S' | 'X' | 'Z' -> "2"
| 'D' | 'T' -> "3"
| 'L' -> "4"
| 'M' | 'N' -> "5"
| 'R' -> "6"
| _ -> ""
let fr = function
| 'B' | 'P' -> "1"
| 'C' | 'K' | 'Q' -> "2"
| 'D' | 'T' -> "3"
| 'L' -> "4"
| 'M' | 'N' -> "5"
| 'R' -> "6"
| 'G' | 'J' -> "7"
| 'X' | 'Z' | 'S' -> "8"
| 'F' | 'V' -> "9"
| _ -> ""
let rec dbl acc = function
| [] -> (List.rev acc)
| c::[] -> List.rev(c::acc)
| c1::(c2::_ as tl) ->
if c1 = c2
then dbl acc tl
else dbl (c1::acc) tl
let pad s =
match String.length s with
| 0 -> s ^ "000"
| 1 -> s ^ "00"
| 2 -> s ^ "0"
| 3 -> s
| _ -> String.sub s 0 3
let soundex_aux lang rem =
pad(String.concat "" (dbl [] (List.map lang rem)))
let soundex ?(lang=en) s =
let s = String.uppercase s in
let cl = ref [] in
String.iter (fun c -> cl := c :: !cl) s;
match dbl [] (List.rev !cl) with
| c::rem -> (String.make 1 c) ^ (soundex_aux lang rem)
| [] -> invalid_arg "soundex"
in the interface as the definition of the type lang is hidden we can use it easily as a classic parameter:
type lang
val en : lang
val fr : lang
val soundex : ?lang:lang -> string -> string
type lang_set = (int * char list) list
val make_lang : lang_set -> lang
The lang parameter for the soundex function is optional, if omited the english set is used.
We put the implementation in the file soundex.ml and the interface in soundex.mli, then we compile with:
ocamlc -c soundex.mli ocamlc -c soundex.ml
Test that the function make_lang provide the same results:
open Soundex
let tests = [
"Soundex"; "Example"; "Sownteks"; "Ekzampul"; "Euler"; "Gauss"; "Hilbert";
"Knuth"; "Lloyd"; "Lukasiewicz"; "Ellery"; "Ghosh"; "Heilbronn"; "Kant";
"Ladd"; "Lissajous"; "Wheaton"; "Ashcraft"; "Burroughs"; "Burrows"; "O'Hara" ]
let fr_set = [
1, ['B'; 'P'];
2, ['C'; 'K'; 'Q'];
3, ['D'; 'T'];
4, ['L'];
5, ['M'; 'N'];
6, ['R'];
7, ['G'; 'J'];
8, ['X'; 'Z'; 'S'];
9, ['F'; 'V'];
]
let my_fr = make_lang fr_set ;;
let () =
print_endline " Word \t Fr Check Status";
List.iter (fun word ->
let code1 = soundex ~lang:Soundex.fr word in
let code2 = soundex ~lang:my_fr word in
let status = if code1 = code2 then "OK " else "Arg" in
Printf.printf " \"%s\" \t %s %s %s\n" word code1 code2 status
) tests
We can run this test file with: ocaml soundex.cmo test.ml