Sentinel in a sentence as a noun

You have to add a nil sentinel value to the end of your list of objects, silly.

And returning false is just a sentinel value, much like functions in other languages might return -1.

That's why I think adding a sentinel return value from the call function is inappropriate.

Real data is different sizes than you expect[1], collides with your sentinel values[2], and comes in with unexpected encodings[3].

In that case, a sentinel return value is no longer inelegant--its appropriate.

You can show this by putting a sentinel value in the queue that separates two stacks and having some crazy loop structures that allow you to push and pop from the two stacks it represents.

The exchange between Antirez and aphyr following the post about Redis sentinel is a fascinating comparison between two engineering approaches.

Proper Noun Examples for Sentinel

* Finally Sentinels persist their state on disk at every configuration update, or every time a new slave or sentinel is added to a master, so the system model is much more reasonable.

Sentinel definitions

noun

a person employed to keep watch for some anticipated event

See also: lookout sentry watch spotter scout picket