# Treeql Shims - Internal

Shims
do_attr
node
op
attr
returns the result of functionally applying op to the node's attribute
shim to perform operation {*}op on attribute attr of node
do_getvals
node
pattern
returns a list of string values of matching attributes
shim to return string values of attributes matching pattern of a given node
do_ancestors
node
shim to find node ancestors by repetitive [parent]
do_previous*
node
do_next*
node
SubQueries
subquery
return result of new query $query, preserving current node set
and
and
construct the set of nodes present in both $nodes and node set $and
or
or
construct the set of nodes present in $nodes or node set $or
not
not
construct the set of nodes present in $nodes but not node set $not