itree.c: Improve division between tree and iterator

* src/buffer.c (delete_all_overlays): Add comment.

* src/itree.c (struct interval_generator): New fields `running`,
`file`, and `line` moved from `interval_tree`.
(interval_stack_push_flagged): Adjust comment to resolve a FIXME.
(interval_tree_clear): Replace assignment with an a
(interval_tree_iter_next): Delete function.
(interval_tree_clear): Don't set `iter_running` here any more.
(interval_generator_create): Set it here instead.
(interval_tree_iter_start): Fetch `iter` once and for all.
(interval_generator_narrow): Mark it as non-static.
(interval_tree_iter_next, interval_tree_iter_narrow):
Delete functions.  Inline their old bodies in the callers.
(interval_tree_iter_finish): Take the iter rather than
the whole tree.  Adjust all callers.
(interval_generator_next): Move `running `assertion here from
`interval_tree_iter_next`.

* src/buffer.h: Adjust accordingly.

* src/itree.h (struct interval_tree): Remove fields `iter_running`,
`file`, and `line`, moved to `interval_generator`.
(interval_generator_narrow): Replace `interval_tree_iter_narrow`.

1 files changed, 3 insertions, 6 deletions

diff --git a/src/itree.h b/src/itree.h
index f1ef7f99463..b9294c5662c 100644
--- a/src/itree.h
+++ b/src/itree.h
@@ -60,9 +60,6 @@ struct interval_tree
   uintmax_t otick;              /* offset tick, compared with node's otick. */
   intmax_t size;                /* Number of nodes in the tree. */
   struct interval_generator *iter;
-  bool_bf iter_running : 1;
-  const char* file;
-  int line;
 };
 
 enum interval_tree_order {
@@ -84,9 +81,9 @@ bool interval_tree_contains (struct interval_tree *, struct interval_node *);
 struct interval_node *interval_tree_remove (struct interval_tree *, struct interval_node *);
 void interval_tree_iter_start (struct interval_tree *, ptrdiff_t, ptrdiff_t, enum interval_tree_order,
 			       const char* file, int line);
-void interval_tree_iter_narrow (struct interval_tree *, ptrdiff_t, ptrdiff_t);
-void interval_tree_iter_finish (struct interval_tree *);
-struct interval_node *interval_tree_iter_next (struct interval_tree *);
+void interval_generator_narrow (struct interval_generator *, ptrdiff_t, ptrdiff_t);
+void interval_tree_iter_finish (struct interval_generator *);
+struct interval_node *interval_generator_next (struct interval_generator *);
 void interval_tree_insert_gap (struct interval_tree *, ptrdiff_t, ptrdiff_t);
 void interval_tree_delete_gap (struct interval_tree *, ptrdiff_t, ptrdiff_t);
 void interval_tree_nodes (struct interval_tree *tree, struct interval_node **nodes, enum interval_tree_order order);