all: change optional to result of io (#16075)

vlib/os/notify/backend_default.c.v

@@ -1,6 +1,6 @@
 module notify
 
 // Implement the API
-pub fn new() ?FdNotifier {
+pub fn new() !FdNotifier {
 	panic('unsupported')
 }

vlib/os/notify/backend_linux.c.v

@@ -43,7 +43,7 @@ pub:
 // new creates a new EpollNotifier
 // The FdNotifier interface is returned to allow OS specific
 // implementations without exposing the concrete type
-pub fn new() ?FdNotifier {
+pub fn new() !FdNotifier {
 	fd := C.epoll_create1(0) // 0 indicates default behavior
 	if fd == -1 {
 		return error(os.posix_get_error_msg(C.errno))
@@ -69,7 +69,7 @@ const (
 )
 
 // ctl is a helper method for add, modify, and remove
-fn (mut en EpollNotifier) ctl(fd int, op int, mask u32) ? {
+fn (mut en EpollNotifier) ctl(fd int, op int, mask u32) ! {
 	event := C.epoll_event{
 		events: mask
 		data: C.epoll_data_t{
@@ -82,20 +82,20 @@ fn (mut en EpollNotifier) ctl(fd int, op int, mask u32) ? {
 }
 
 // add adds a file descriptor to the watch list
-fn (mut en EpollNotifier) add(fd int, events FdEventType, conf ...FdConfigFlags) ? {
+fn (mut en EpollNotifier) add(fd int, events FdEventType, conf ...FdConfigFlags) ! {
 	mask := flags_to_mask(events, ...conf)
-	en.ctl(fd, C.EPOLL_CTL_ADD, mask)?
+	en.ctl(fd, C.EPOLL_CTL_ADD, mask)!
 }
 
 // modify sets an existing entry in the watch list to the provided events and configuration
-fn (mut en EpollNotifier) modify(fd int, events FdEventType, conf ...FdConfigFlags) ? {
+fn (mut en EpollNotifier) modify(fd int, events FdEventType, conf ...FdConfigFlags) ! {
 	mask := flags_to_mask(events, ...conf)
-	en.ctl(fd, C.EPOLL_CTL_MOD, mask)?
+	en.ctl(fd, C.EPOLL_CTL_MOD, mask)!
 }
 
 // remove removes a file descriptor from the watch list
-fn (mut en EpollNotifier) remove(fd int) ? {
-	en.ctl(fd, C.EPOLL_CTL_DEL, 0)?
+fn (mut en EpollNotifier) remove(fd int) ! {
+	en.ctl(fd, C.EPOLL_CTL_DEL, 0)!
 }
 
 // wait waits to be notified of events on the watch list,
@@ -133,7 +133,7 @@ fn (mut en EpollNotifier) wait(timeout time.Duration) []FdEvent {
 
 // close closes the EpollNotifier,
 // any successive calls to add, modify, remove, and wait should fail
-fn (mut en EpollNotifier) close() ? {
+fn (mut en EpollNotifier) close() ! {
 	if C.close(en.epoll_fd) == -1 {
 		return error(os.posix_get_error_msg(C.errno))
 	}

vlib/os/notify/notify.v

@@ -5,11 +5,11 @@ import time
 // Backends should provide a `new()?FdNotifier` function
 pub interface FdNotifier {
 mut:
-	add(fd int, events FdEventType, conf ...FdConfigFlags) ?
-	modify(fd int, events FdEventType, conf ...FdConfigFlags) ?
-	remove(fd int) ?
+	add(fd int, events FdEventType, conf ...FdConfigFlags) !
+	modify(fd int, events FdEventType, conf ...FdConfigFlags) !
+	remove(fd int) !
 	wait(timeout time.Duration) []FdEvent
-	close() ?
+	close() !
 }
 
 pub interface FdEvent {

vlib/os/notify/notify_test.v

@@ -4,7 +4,7 @@ import os
 import os.notify
 
 // make a pipe and return the (read, write) file descriptors
-fn make_pipe() ?(int, int) {
+fn make_pipe() !(int, int) {
 	$if linux {
 		pipefd := [2]int{}
 		if C.pipe(&pipefd[0]) != 0 {
@@ -18,14 +18,14 @@ fn make_pipe() ?(int, int) {
 fn test_level_trigger() {
 	// currently only linux is supported
 	$if linux {
-		mut notifier := notify.new()?
-		reader, writer := make_pipe()?
+		mut notifier := notify.new()!
+		reader, writer := make_pipe()!
 		defer {
 			os.fd_close(reader)
 			os.fd_close(writer)
 			notifier.close() or {}
 		}
-		notifier.add(reader, .read)?
+		notifier.add(reader, .read)!
 
 		os.fd_write(writer, 'foobar')
 		mut n := &notifier
@@ -39,14 +39,14 @@ fn test_level_trigger() {
 fn test_edge_trigger() {
 	// currently only linux is supported
 	$if linux {
-		mut notifier := notify.new()?
-		reader, writer := make_pipe()?
+		mut notifier := notify.new()!
+		reader, writer := make_pipe()!
 		defer {
 			os.fd_close(reader)
 			os.fd_close(writer)
 			notifier.close() or {}
 		}
-		notifier.add(reader, .read, .edge_trigger)?
+		notifier.add(reader, .read, .edge_trigger)!
 
 		mut n := &notifier
 
@@ -66,14 +66,14 @@ fn test_edge_trigger() {
 
 fn test_one_shot() {
 	$if linux {
-		mut notifier := notify.new()?
-		reader, writer := make_pipe()?
+		mut notifier := notify.new()!
+		reader, writer := make_pipe()!
 		defer {
 			os.fd_close(reader)
 			os.fd_close(writer)
 			notifier.close() or {}
 		}
-		notifier.add(reader, .read, .one_shot)?
+		notifier.add(reader, .read, .one_shot)!
 
 		mut n := &notifier
 
@@ -84,20 +84,20 @@ fn test_one_shot() {
 		assert notifier.wait(0).len == 0
 
 		// rearm
-		notifier.modify(reader, .read)?
+		notifier.modify(reader, .read)!
 		check_read_event(mut n, reader, 'barbaz')
 	}
 }
 
 fn test_hangup() {
 	$if linux {
-		mut notifier := notify.new()?
-		reader, writer := make_pipe()?
+		mut notifier := notify.new()!
+		reader, writer := make_pipe()!
 		defer {
 			os.fd_close(reader)
 			notifier.close() or {}
 		}
-		notifier.add(reader, .hangup)?
+		notifier.add(reader, .hangup)!
 
 		assert notifier.wait(0).len == 0
 
@@ -113,18 +113,18 @@ fn test_hangup() {
 
 fn test_write() {
 	$if linux {
-		mut notifier := notify.new()?
-		reader, writer := make_pipe()?
+		mut notifier := notify.new()!
+		reader, writer := make_pipe()!
 		defer {
 			os.fd_close(reader)
 			os.fd_close(writer)
 			notifier.close() or {}
 		}
 
-		notifier.add(reader, .write)?
+		notifier.add(reader, .write)!
 		assert notifier.wait(0).len == 0
 
-		notifier.add(writer, .write)?
+		notifier.add(writer, .write)!
 		events := notifier.wait(0)
 		assert events.len == 1
 		assert events[0].fd == writer
@@ -134,8 +134,8 @@ fn test_write() {
 
 fn test_remove() {
 	$if linux {
-		mut notifier := notify.new()?
-		reader, writer := make_pipe()?
+		mut notifier := notify.new()!
+		reader, writer := make_pipe()!
 		defer {
 			os.fd_close(reader)
 			os.fd_close(writer)
@@ -144,12 +144,12 @@ fn test_remove() {
 
 		// level triggered - will keep getting events while
 		// there is data to read
-		notifier.add(reader, .read)?
+		notifier.add(reader, .read)!
 		os.fd_write(writer, 'foobar')
 		assert notifier.wait(0).len == 1
 		assert notifier.wait(0).len == 1
 
-		notifier.remove(reader)?
+		notifier.remove(reader)!
 		assert notifier.wait(0).len == 0
 	}
 }