Add uniq() function (#705)

Author: OlgaNovg

builtin/builtin.go

@@ -830,6 +830,57 @@ var Builtins = []*Function{
 			}
 		},
 	},
+
+	{
+		Name: "uniq",
+		Func: func(args ...any) (any, error) {
+			if len(args) != 1 {
+				return nil, fmt.Errorf("invalid number of arguments (expected 1, got %d)", len(args))
+			}
+
+			v := reflect.ValueOf(deref.Deref(args[0]))
+			if v.Kind() != reflect.Array && v.Kind() != reflect.Slice {
+				return nil, fmt.Errorf("cannot uniq %s", v.Kind())
+			}
+
+			size := v.Len()
+			ret := []any{}
+
+			eq := func(i int) bool {
+				for _, r := range ret {
+					if runtime.Equal(v.Index(i).Interface(), r) {
+						return true
+					}
+				}
+
+				return false
+			}
+
+			for i := 0; i < size; i += 1 {
+				if eq(i) {
+					continue
+				}
+
+				ret = append(ret, v.Index(i).Interface())
+			}
+
+			return ret, nil
+		},
+
+		Validate: func(args []reflect.Type) (reflect.Type, error) {
+			if len(args) != 1 {
+				return anyType, fmt.Errorf("invalid number of arguments (expected 1, got %d)", len(args))
+			}
+
+			switch kind(args[0]) {
+			case reflect.Interface, reflect.Slice, reflect.Array:
+				return arrayType, nil
+			default:
+				return anyType, fmt.Errorf("cannot uniq %s", args[0])
+			}
+		},
+	},
+
 	{
 		Name: "concat",
 		Safe: func(args ...any) (any, uint, error) {

builtin/builtin_test.go

@@ -155,6 +155,8 @@ func TestBuiltin(t *testing.T) {
 		{`flatten([["a", "b"], [1, 2]])`, []any{"a", "b", 1, 2}},
 		{`flatten([["a", "b"], [1, 2, [3, 4]]])`, []any{"a", "b", 1, 2, 3, 4}},
 		{`flatten([["a", "b"], [1, 2, [3, [[[["c", "d"], "e"]]], 4]]])`, []any{"a", "b", 1, 2, 3, "c", "d", "e", 4}},
+		{`uniq([1, 15, "a", 2, 3, 5, 2, "a", 2, "b"])`, []any{1, 15, "a", 2, 3, 5, "b"}},
+		{`uniq([[1, 2], "a", 2, 3, [1, 2], [1, 3]])`, []any{[]any{1, 2}, "a", 2, 3, []any{1, 3}}},
 	}
 
 	for _, test := range tests {