The PermanentIndices command returns the indices of the permanent entries of the given cache table.  The cache table can be given directly as cache, or cache can refer to a procedure that has, or can have, a cache remember table.  If such a procedure is given and it has a cache remember table, the keys of the permanent indices from that table are returned.  If the procedure does not have a table, NULL is returned.

PermanentIndices returns the indices in the same format as indices, that is, a sequence of lists where the contents of each list is an index of a permanent entry from the table.

The PermanentEntries command can be used to get the indices of the permanent entries.

For more information on cache tables, see Cache Package.

$\mathrm{c1}≔\mathrm{Cache}\left(\right)$

$\mathrm{c1}≔\mathrm{Cache}\left(512\right)$

$\mathrm{Cache}:-\mathrm{AddPermanent}\left(\mathrm{c1}\,\left[x\right]\,y\right)$

$\mathrm{Cache}:-\mathrm{AddPermanent}\left(\mathrm{c1}\,\left[y\right]\,z\right)$

$\mathrm{Cache}:-\mathrm{PermanentEntries}\left(\mathrm{c1}\right)$

$\left[y\right],\left[z\right]$

$\mathrm{Cache}:-\mathrm{PermanentIndices}\left(\mathrm{c1}\right)$

$\left[x\right],\left[y\right]$

p := proc( x ) option cache; x^2; end proc;

$p≔\mathbf{proc}\left(x\right)\mathbf{option}\mathrm{cache}\;x\^2\mathbf{end\; proc}$

$\mathrm{Cache}:-\mathrm{AddPermanent}\left(p\,\left[2\right]\,2\right)$

$\mathrm{Cache}:-\mathrm{AddPermanent}\left(p\,\left[3\right]\,3\right)$

$\mathrm{Cache}:-\mathrm{PermanentEntries}\left(p\right)$

$\left[2\right],\left[3\right]$

$\mathrm{Cache}:-\mathrm{PermanentIndices}\left(p\right)$

$\left[2\right],\left[3\right]$