Version 2.9 is the next step towards version 3.0, improving ISO
compliance and introducing ISO compliant exception handling. New are
catch/3, throw/1, abolish/1, write_term/[2,3], write_canonical/[1,2]
and the C-functions PL_exception()
and PL_throw(). The predicates
display/[1,2] and displayq/[1,2]
have been moved to library(backcomp), so old code referring
to them will autoload them.
The interface to PL_open_query()
has changed. The debug argument is replaced by a bitwise
or'ed flags argument. The values
FALSE and TRUE have their familiar meaning,
making old code using these constants compatible. Non-zero values other
than
TRUE (1) will be interpreted different.