void
edit_env_rep::local_end (hashmap<string,tree>& prev_back) {
int i=0, n=back->n;
for (; i<n; i++) {
list<hashentry<string,tree> > l=back->a[i];
for (; !is_nil(l); l=l->next)
prev_back->write_back (l->item.key, back);
}
back= prev_back;
}
inline void assign (string s, tree t) {
tree& val= env (s); t= exec(t); if (val != t) {
back->write_back (s, env); val= t; update (s); } }
inline void monitored_write_update (string s, tree t) {
back->write_back (s, env); env (s)= t; update (s); }