promise_catch

NAME

promise_catch - attach a rejection handler

SYNOPSIS

promise promise_catch(promise p, function on_rejected);

DESCRIPTION

Attaches only a rejection handler and returns the chained promise.
Fulfillment passes through unchanged; a rejection runs
`on_rejected(reason)`, whose return value fulfills the chained promise.

This is the rejection-only half of `promise_then()`, which cannot be
spelled with `promise_then()` itself: its second argument must be a
function whenever a third is given, so `promise_then(p, 0, f)` is a
runtime error ("Bad argument 2 to promise_then()").

SEE ALSO

promise_then(3), promise_reject(3)