Emergency Breaks for J/UnixYou can interrupt the currently running J program by hitting Ctrl-C:J 4.02 Copyright (c) 1990-1998, Iverson Software Inc. All rights reserved. loopdemo =: monad define for_i. i. y. do. 1!:2&2 i NB. write to screen 6!:3 ] 5 NB. 5 seconds delay end. y. ) loopdemo 4 0 1 2 3 4 loopdemo 4 0 1 ^C|break: loopdemo | 6!:3]5 NB. 5 seconds delay
The break is an event which will trigger the debugger or any try./catch. if enabled.
Note that a break can only take effect after a J primitive (or, at the discretion of the implementation, even a phrase of a few primitives) has been completed. In the example above, you have to wait until the currently running pause is completed. Likewise for long running matrix computations, blocking reads from a socket etc.