Function: parselect
Section: programming/parallel
C-Name: parselect
Prototype: GGD0,L,
Help: parselect(f, A, {flag = 0}): (parallel select) selects elements of A
 according to the selection function f which is tested in parallel. If flag
 is 1, return the indices of those elements (indirect selection).
Doc: selects elements of $A$ according to the selection function $f$, done in
 parallel.  If \fl is $1$, return the indices of those elements (indirect
 selection) The function \kbd{f} must not access global variables or
 variables declared with local(), and must be free of side effects.

Function: _parselect_worker
Section: programming/internals
C-Name: parselect_worker
Prototype: GG
Help: _parselect_worker(d,C): evaluate the boolean closure C on d.
