Restricted evaluation of a parse tree

reval x     reval[x]

The reval function is similar to eval, and behaves as if the command-line option -b were active during evaluation.

An example usage is inside the message handler .z.pg, useful for access control, here blocking sync messages from updating:

q).z.pg:{reval(value;enlist x)} / define in process listening on port 5000
q)h:hopen 5000 / from another process on same host
q)h"a:4"
'noupdate: `. `a