[list] IndexOf.

AST.ci

@@ -123,6 +123,7 @@ public enum CiId
 	ListContains,
 	ListCopyTo,
 	ListCount,
+	ListIndexOf,
 	ListInsert,
 	ListLast,
 	ListRemoveAt,
@@ -1477,6 +1478,7 @@ public class CiSystem : CiScope
 		listClass.Add(CiMethod.New(CiVisibility.Public, BoolType, CiId.ListContains, "Contains", CiVar.New(TypeParam0, "value")));
 		listClass.Add(CiMethod.New(CiVisibility.Public, VoidType, CiId.ListCopyTo, "CopyTo", CiVar.New(IntType, "sourceIndex"),
 			CiVar.New(new CiReadWriteClassType { Class = ArrayPtrClass, TypeArg0 = TypeParam0 }, "destinationArray"), CiVar.New(IntType, "destinationIndex"), CiVar.New(IntType, "count")));
+		listClass.Add(CiMethod.NewMutator(CiVisibility.Public, IntType, CiId.ListIndexOf, "IndexOf", CiVar.New(TypeParam0, "value")));
 		listClass.Add(CiMethod.NewMutator(CiVisibility.Public, VoidType, CiId.ListInsert, "Insert", CiVar.New(UIntType, "index"), CiVar.New(typeParam0NotFinal, "value")));
 		listClass.Add(CiMethod.NewMutator(CiVisibility.Public, TypeParam0, CiId.ListLast, "Last"));
 		listClass.Add(CiMethod.NewMutator(CiVisibility.Public, VoidType, CiId.ListRemoveAt, "RemoveAt", CiVar.New(IntType, "index")));

GenCpp.cs

@@ -822,6 +822,17 @@ protected override void WriteCallExpr(CiExpr obj, CiMethod method, List<CiExpr>
 			if (parent > CiPriority.Equality)
 				WriteChar(')');
 			break;
+		case CiId.ListIndexOf:
+			{
+				CiType elementType = ((CiClassType) obj.Type).GetElementType();
+				Write("[](");
+				WriteCollectionType("vector", elementType);
+				Write(" &v, const ");
+				WriteType(elementType, false);
+			}
+			Include("algorithm");
+			WriteCall(" &value) { auto i = std::find(v.begin(), v.end(), value); return i == v.end() ? -1 : i - v.begin(); }", obj, args[0]);
+			break;
 		case CiId.ListInsert:
 			StartMethodCall(obj);
 			if (args.Count == 1) {

GenJs.cs

@@ -492,6 +492,7 @@ protected override void WriteCallExpr(CiExpr obj, CiMethod method, List<CiExpr>
 		case CiId.StringLastIndexOf:
 		case CiId.StringStartsWith:
 		case CiId.ArraySortAll:
+		case CiId.ListIndexOf:
 		case CiId.StackPush:
 		case CiId.StackPop:
 		case CiId.HashSetAdd:

GenPy.cs

@@ -535,6 +535,13 @@ protected override void WriteNew(CiReadWriteClassType klass, CiPriority parent)
 		}
 	}
 
+	void WriteContains(CiExpr haystack, CiExpr needle)
+	{
+		needle.Accept(this, CiPriority.Rel);
+		Write(" in ");
+		haystack.Accept(this, CiPriority.Rel);
+	}
+
 	void WriteSlice(CiExpr startIndex, CiExpr length)
 	{
 		WriteChar('[');
@@ -601,9 +608,7 @@ protected override void WriteCallExpr(CiExpr obj, CiMethod method, List<CiExpr>
 		case CiId.DictionaryContainsKey:
 		case CiId.SortedDictionaryContainsKey:
 		case CiId.OrderedDictionaryContainsKey:
-			args[0].Accept(this, CiPriority.Rel);
-			Write(" in ");
-			obj.Accept(this, CiPriority.Rel);
+			WriteContains(obj, args[0]);
 			break;
 		case CiId.StringEndsWith:
 			WriteMethodCall(obj, "endswith", args[0]);
@@ -699,6 +704,16 @@ protected override void WriteCallExpr(CiExpr obj, CiMethod method, List<CiExpr>
 			else
 				WritePostfix(obj, ".clear()");
 			break;
+		case CiId.ListIndexOf:
+			if (parent > CiPriority.Select)
+				WriteChar('(');
+			WriteMethodCall(obj, "index", args[0]);
+			Write(" if ");
+			WriteContains(obj, args[0]); // TODO: side effects
+			Write(" else -1");
+			if (parent > CiPriority.Select)
+				WriteChar(')');
+			break;
 		case CiId.ListInsert:
 			WriteListInsert(obj, "insert", args);
 			break;

GenSwift.cs

@@ -578,6 +578,15 @@ protected override void WriteCallExpr(CiExpr obj, CiMethod method, List<CiExpr>
 		case CiId.SortedDictionaryClear:
 			WritePostfix(obj, ".removeAll()");
 			break;
+		case CiId.ListIndexOf:
+			if (parent > CiPriority.Rel)
+				WriteChar('(');
+			WritePostfix(obj, ".firstIndex(of: ");
+			args[0].Accept(this, CiPriority.Argument);
+			Write(") ?? -1");
+			if (parent > CiPriority.Rel)
+				WriteChar(')');
+			break;
 		case CiId.ListInsert:
 			WritePostfix(obj, ".insert(");
 			CiType elementType = ((CiClassType) obj.Type).GetElementType();

Transpiled.cs

@@ -1309,6 +1309,7 @@ public enum CiId
 		ListContains,
 		ListCopyTo,
 		ListCount,
+		ListIndexOf,
 		ListInsert,
 		ListLast,
 		ListRemoveAt,
@@ -2920,6 +2921,7 @@ internal CiSystem()
 			listClass.Add(CiMethod.New(CiVisibility.Public, this.BoolType, CiId.ListAny, "Any", CiVar.New(typeParam0Predicate, "predicate")));
 			listClass.Add(CiMethod.New(CiVisibility.Public, this.BoolType, CiId.ListContains, "Contains", CiVar.New(this.TypeParam0, "value")));
 			listClass.Add(CiMethod.New(CiVisibility.Public, this.VoidType, CiId.ListCopyTo, "CopyTo", CiVar.New(this.IntType, "sourceIndex"), CiVar.New(new CiReadWriteClassType { Class = this.ArrayPtrClass, TypeArg0 = this.TypeParam0 }, "destinationArray"), CiVar.New(this.IntType, "destinationIndex"), CiVar.New(this.IntType, "count")));
+			listClass.Add(CiMethod.NewMutator(CiVisibility.Public, this.IntType, CiId.ListIndexOf, "IndexOf", CiVar.New(this.TypeParam0, "value")));
 			listClass.Add(CiMethod.NewMutator(CiVisibility.Public, this.VoidType, CiId.ListInsert, "Insert", CiVar.New(this.UIntType, "index"), CiVar.New(typeParam0NotFinal, "value")));
 			listClass.Add(CiMethod.NewMutator(CiVisibility.Public, this.TypeParam0, CiId.ListLast, "Last"));
 			listClass.Add(CiMethod.NewMutator(CiVisibility.Public, this.VoidType, CiId.ListRemoveAt, "RemoveAt", CiVar.New(this.IntType, "index")));

doc/reference.md

@@ -924,6 +924,8 @@ You can remove:
 * A continuous sequence of elements with `RemoveRange(index, count)`.
 
 `list.Contains(value)` returns `true` if the list contains the specified item.
+`list.IndexOf(value)` returns the position of the specified element
+or -1 if not found.
 
 `list.CopyTo(sourceIndex, destinationArray, destinationIndex, count)`
 copies elements from a list to an array.

test/ListIndexOf.ci

@@ -0,0 +1,21 @@
+public static class Test
+{
+	public static bool Run()
+	{
+		List<int>() li; //FAIL: cl
+		li.Add(42);
+		li.Add(15);
+		li.Add(15);
+
+		List<string>() lsp;
+		lsp.Add("foo");
+		lsp.Add("bar");
+
+		List<string()>() lss;
+		lss.Add("foo");
+		lss.Add("bar");
+		return li.IndexOf(15) == 1 && li.IndexOf(1) == -1 //FAIL: c
+			&& lsp.IndexOf("bar") == 1 && lsp.IndexOf("quux") == -1
+			&& lss.IndexOf("bar") == 1 && lss.IndexOf("quux") == -1;
+	}
+}