equery/depends: print output in module rather than with a callback

The depends module can now iterate over the results of the
graph_reverse_depends function and print the items as they are
yielded.

Before, it passed in a callback printer function, and expected the
Dependencies class to call it correctly.

This setup is nicer because it does not tie together this module and
the Dependencies class, and the old setup most likely existed due to
performance and interactivity concerns which are now fixed by turning
graph_reverse_depends into an iterator.

pym/gentoolkit/equery/depends.py

@@ -17,7 +17,6 @@
 from gentoolkit.dependencies import Dependencies
 from gentoolkit.equery import format_options, mod_usage, CONFIG
 from gentoolkit.helpers import get_cpvs, get_installed_cpvs
-from gentoolkit.cpv import CPV
 from gentoolkit.package import PackageFormatter, Package
 
 # =======
@@ -27,7 +26,7 @@
 QUERY_OPTS = {
     "include_masked": False,
     "only_direct": True,
-    "max_depth": -1,
+    "max_depth": None,
     "package_format": None,
 }
 
@@ -94,9 +93,9 @@ def format_depend(self, dep, dep_is_displayed):
         if dep_is_displayed and not self.verbose:
             return
 
-        depth = getattr(dep, "depth", 0)
+        depth = dep.depth
         indent = " " * depth
-        mdep = dep.matching_dep
+        mdep = dep.depatom
         use_conditional = ""
 
         if QUERY_OPTS["package_format"] != None:
@@ -226,17 +225,28 @@ def main(input_args):
 
         if CONFIG["verbose"]:
             print(" * These packages depend on %s:" % pp.emph(pkg.cpv))
-        if pkg.graph_reverse_depends(
-            pkgset=sorted(pkggetter(), key=CPV),
-            max_depth=QUERY_OPTS["max_depth"],
+
+        first_run = False
+
+        last_seen = None
+        for pkgdep in pkg.graph_reverse_depends(
+            pkgset=sorted(pkggetter()),
             only_direct=QUERY_OPTS["only_direct"],
-            printer_fn=dep_print,
+            max_depth=QUERY_OPTS["max_depth"],
         ):
+            match last_seen:
+                case None:
+                    seen = False
+                case p if p != pkgdep:
+                    seen = False
+                case _:
+                    seen = True
+            dep_print(pkgdep, dep_is_displayed=seen)
+            last_seen = pkgdep
+        if last_seen is not None:
             got_match = True
 
-        first_run = False
-
-    if not got_match:
+    if got_match is None:
         sys.exit(1)