[Bug-readline] How does readline know where words end (psql and yank-last-arg use case)?

[Alexander Shulgin]

Hello,

I'm just wondering how does readline know where any given word ends
and another one starts?

Does it just check for space/punctuation symbols?  Can this be
configured via inputrc or any other means?

My use case is psql, where due to SQL standard almost every given
command ends with semicolon.  More than often when typing a command
I'd like to re-use the last word from the previous line (which is
often a table name,) but pressing M-. (yank-last-arg) yanks the
semicolon instead.

I know I can use M-- M-. to achieve the desired effect, but this is
more cumbersome to type than plain M-.  Is there any way to tweak
this?

--
Regards,
Alex