Release Notes J9.5

Work on J9.5 started in March 2023. J9.5.0-beta1 was released 20230423.

Changes to the J engine

Summary of Changes to the J Language in the release

new primitive: u m. n performs the operation u(mod n), i. e. using modular arithmetic. n and any arguments to the derived verb must be tolerantly integral or extended integer; results will be integer or extended integer; u must be one of + - * % ^ %. (-/ . *). The derived verb has only dyadic valence except for (% m. n) and (%. m. n) which are bivalent.
domain of x ;: y expanded: new actions added.

unreleased work in progress

J9.5.0-beta2 (the current beta)

x m} y now has Integrated Rank Support. x m}"n y, formerly deprecated, is now recommended.
domain of x ;: y expanded: new actions added. This code was contributed by Danil Osipchuk.
0 % m. n 0 is 0
-/ . * m. n calculates modular determinant. This code was contributed by Cliff Reiter.
complementary indexing (triple-boxed selectors) faster

J9.5.0-beta1

0!:n (used by the load and script verbs) discards the first line of a file if the first two characters in the line are #!
x integer_atom&|@^ y recoded, about 2x faster
special code for (x -@{`[`]} y (also with @:), which changes the sign of the address cells of y, when y is floating-point. Supports inplacing.
new primitive: u m. n performs the operation u(mod n), i. e. using modular arithmetic. n and any arguments to the derived verb must be tolerantly integral or extended integer; results will be integer or extended integer; u must be one of + - * % ^ %.. The derived verb has only dyadic valence except for (% m. n) and (%. m. n) which are bivalent.
The code for %. m. n was contributed by Cliff Reiter.