Skip to content

math.fsum: handle special values (inf, nan); -inf + inf raises ValueError #2727

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
PierreQuentel merged 1 commit into from
Jun 12, 2026
+18 −0
Merged

math.fsum: handle special values (inf, nan); -inf + inf raises ValueError #2727

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 18 additions & 0 deletions www/src/libs/math.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1410,12 +1410,24 @@ function fsum(x) {
*/
var partials = [],
res = new Number(),
inf_sum = 0,
special_sum = 0,
_it = _b_.iter(x)
while (true) {
try {
var x = _b_.next(_it),
i = 0
x = float_check(x)
if (! isFinite(x)) {
// Special values: track infinities and nans separately, as
// CPython's math_fsum does, so that inf + inf returns inf,
// nan propagates, and -inf + inf raises ValueError below.
if (x === Infinity || x === -Infinity) {
inf_sum += x
}
special_sum += x
continue
}
for (var j = 0, len = partials.length; j < len; j++) {
var y = float_check(partials[j])
if (Math.abs(x) < Math.abs(y)) {
Expand All @@ -1437,6 +1449,12 @@ function fsum(x) {
throw err
}
}
if (special_sum !== 0) {
if (isNaN(inf_sum)) {
$B.RAISE(_b_.ValueError, '-inf + inf in fsum')
}
return $B.fast_float(special_sum)
}
var res = 0
for (var i = 0; i < partials.length; i++) {
res += partials[i]
Expand Down