vault backup: 2023-09-07 16:26:16

Algo/Séminaire/Chapter 3 - Case analysis.md

@@ -68,9 +68,34 @@ match expr with pattern1 -> result1 | pattern2 -> result2 | ... | patternn -> re
 # let f x = match x with 
 	0 -> 18
 	| 1 -> 24
-	| y ->  y + y;;
+	| y ->  y * y;;
 
 val f : int -> int = <fun>
 
 # f 1;;
 - : int = 24
+
+# let g x = match x with
+	0 -> 18
+	| y -> y + y (*here will return a warning : unused case*)
+	| 1 -> 24 ;;
+
+val f : int -> int = <fun>
+# f 1;;
+- : int = 1
+
+# let d x = match x with 
+	0 -> 18;
+	| 1 -> 24;;
+	(* Warning = pattern matching not exhaustive *)
+```
+
+### Filtering several values
+
+```Ocaml
+# let and_ a b =
+	match a with 
+		true -> match b with 
+			true -> true
+			| false -> false
+		| false -> false;;