rewrite expand_or in matcher.ml (closes #2610, reopens #2508)

matcher.ml

@@ -524,7 +524,7 @@ let to_pattern ctx e t =
 			let pat1 = loop pctx e1 t in
 			begin match pat1.p_def with
 				| PAny | PVar _ ->
-					ctx.com.warning "This pattern is unused" (pos e2);
+					display_error ctx "This pattern is unused" (pos e2);
 					pat1
 				| _ ->
 					let pctx2 = {
@@ -682,47 +682,44 @@ let swap_columns i (row : 'a list) : 'a list =
 	| _ ->
 		[]
 
-let expand_or mctx pmat =
-	let rec loop pmat = match pmat with
+let expand_or mctx (pmat : pat_matrix) =
+	let rec loop pat = match pat.p_def with
+		| POr(pat1,pat2) ->
+			let pat1 = loop pat1 in
+			let pat2 = loop pat2 in
+			pat1 @ pat2
+		| PBind(v,pat1) ->
+			let pat1 = loop pat1 in
+			List.map (fun pat1 ->
+				{pat with p_def = PBind(v,pat1)}
+			) pat1
+		| PTuple(pl) ->
+			let pat1 = loop pl.(0) in
+			List.map (fun pat1 ->
+				let a1 = Array.copy pl in
+				a1.(0) <- pat1;
+				{pat with p_def = PTuple a1}
+			) pat1
+		| _ ->
+			[pat]
+	in
+	let rec loop2 pmat = match pmat with
 		| (pv,out) :: pmat ->
-			let acc = ref [] in
-			let rec loop2 pv out = match pv.(0) with
-				| {p_def = POr(pat1,pat2)} ->
-					out.o_pos <- pat1.p_pos;
-					let out2 = clone_out mctx out pat2.p_pos in
-					let tl = array_tl pv in
-					loop2 (Array.append [|pat2|] tl) out2;
-					loop2 (Array.append [|pat1|] tl) out;
-				| {p_def = PBind(v,{p_def = POr(pat1,pat2)})} as pat ->
-					out.o_pos <- pat1.p_pos;
-					let out2 = clone_out mctx out pat2.p_pos in
-					let tl = array_tl pv in
-					loop2 (Array.append [|{pat with p_def = PBind(v,pat2)}|] tl) out2;
-					loop2 (Array.append [|{pat with p_def = PBind(v,pat1)}|] tl) out;
-				| {p_def = PTuple tl} as pat ->
-					begin match tl.(0).p_def with
-					 	| POr(pat1,pat2) ->
-							let out2 = clone_out mctx out pat2.p_pos in
-							let a1 = Array.copy tl in
-							a1.(0) <- pat1;
-							let a2 = Array.copy tl in
-							a2.(0) <- pat2;
-							let tl = array_tl pv in
-							loop2 (Array.append [|{pat with p_def = PTuple a2}|] tl) out2;
-							loop2 (Array.append [|{pat with p_def = PTuple a1}|] tl) out;
-					 	| _ ->
-					 		acc := (pv,out) :: !acc
-					 end
-				| _ ->
-					acc := (pv,out) :: !acc
-			in
-			let r = loop pmat in
-			loop2 pv out;
-			!acc @ r
+			let pat = loop pv.(0) in
+			let pat' = ExtList.List.mapi (fun i pat ->
+				(* TODO: This should really be active, but currently causes problems with or-patterns in
+				   tuples (issue #2610). We will disable this for the 3.1.0 release, which means issue
+				   #2508 is open again. *)
+				(* let out = if i = 0 then out else clone_out mctx out pat.p_pos in *)
+				let a1 = Array.copy pv in
+				a1.(0) <- pat;
+				a1,out
+			) pat in
+			pat' @ (loop2 pmat)
 		| [] ->
 			[]
 	in
-	loop pmat
+	loop2 pmat
 
 let column_sigma mctx st pmat =
 	let acc = ref [] in

tests/unit/issues/Issue2610.hx

@@ -0,0 +1,35 @@
+package unit.issues;
+import unit.Test;
+
+
+class Issue2610 extends Test {
+	function test() {
+		function map(i1, i2) {
+			return switch [i1, i2] {
+				case [1, 1]: 1;
+				case [1 | 2, 2 | 1]: 2;
+				case _: 3;
+			}
+		}
+		
+		eq(1, map(1, 1));
+		eq(2, map(1, 2));
+		eq(2, map(2, 1));
+		eq(2, map(2, 2));
+		eq(3, map(2, 3));
+		
+		function map2(i1, i2) {
+			return switch [i1, i2] {
+				case [1, 1]: "1+1";
+				case [a = 1 | 2, b = 2 | 1]: '$a+$b';
+				case _: "_";
+			}
+		}
+		
+		eq("1+1", map2(1, 1));
+		eq("1+2", map2(1, 2));
+		eq("2+1", map2(2, 1));
+		eq("2+2", map2(2, 2));
+		eq("_", map2(2, 3));
+	}
+}