Move error handling code into its own library

tools/utils/misc.go

@@ -68,80 +68,6 @@ func Filter[T any](s []T, f func(x T) bool) []T {
 	return ans
 }
 
-func Format_stacktrace_on_panic(r any) (text string, err error) {
-	pcs := make([]uintptr, 512)
-	n := runtime.Callers(3, pcs)
-	lines := []string{}
-	frames := runtime.CallersFrames(pcs[:n])
-	rt := fmt.Sprint(r)
-	if strings.HasPrefix(rt, "Panicked with error:") {
-		err = fmt.Errorf("%s", rt)
-		lines = append(lines, "Panic caused by previous panic (probably in a gouroutine). Previous panic:\r\n")
-		lines = append(lines, rt)
-		lines = append(lines, "\r\n\r\nStacktrace of current panic (most recent call first):\r\n")
-	} else {
-		err = fmt.Errorf("Panicked: %s", r)
-		lines = append(lines, fmt.Sprintf("\r\nPanicked with error: %s\r\nStacktrace (most recent call first):\r\n", r))
-	}
-	found_first_frame := false
-	for frame, more := frames.Next(); more; frame, more = frames.Next() {
-		if !found_first_frame {
-			if strings.HasPrefix(frame.Function, "runtime.") {
-				continue
-			}
-			found_first_frame = true
-		}
-		lines = append(lines, fmt.Sprintf("%s\r\n\t%s:%d\r\n", frame.Function, frame.File, frame.Line))
-	}
-	text = strings.Join(lines, "")
-	return strings.TrimSpace(text), err
-}
-
-// Run the specified function in parallel over chunks from the specified range.
-// If the function panics, it is turned into a regular error.
-func Run_in_parallel_over_range(num_procs int, f func(int, int) error, start, limit int) (err error) {
-	num_items := limit - start
-	if num_procs <= 0 {
-		num_procs = runtime.NumCPU()
-	}
-	num_procs = max(1, min(num_procs, num_items))
-	if num_procs < 2 {
-		defer func() {
-			if r := recover(); r != nil {
-				stacktrace, e := Format_stacktrace_on_panic(r)
-				err = fmt.Errorf("%s\n\n%w", stacktrace, e)
-			}
-		}()
-		return f(start, limit)
-	}
-	chunk_sz := max(1, num_items/num_procs)
-	var wg sync.WaitGroup
-	echan := make(chan error, num_procs)
-	for start < limit {
-		end := min(start+chunk_sz, limit)
-		wg.Add(1)
-		go func(start, end int) {
-			defer func() {
-				if r := recover(); r != nil {
-					stacktrace, e := Format_stacktrace_on_panic(r)
-					echan <- fmt.Errorf("%s\n\n%w", stacktrace, e)
-				}
-				wg.Done()
-			}()
-			if err := f(start, end); err != nil {
-				echan <- err
-			}
-		}(start, end)
-		start = end
-	}
-	wg.Wait()
-	close(echan)
-	for qerr := range echan {
-		return qerr
-	}
-	return
-
-}
 func Map[T any, O any](f func(x T) O, s []T) []O {
 	ans := make([]O, 0, len(s))
 	for _, x := range s {