Update docs again.

[pyutils.git] / src / pyutils / collectionz / interval_tree.py

diff --git a/src/pyutils/collectionz/interval_tree.py b/src/pyutils/collectionz/interval_tree.py
index c78465c65fdf72c581df22c17c057330bdce0113..d4b33cbe62dea02385b1381924429ff2ebb613f7 100644 (file)
--- a/src/pyutils/collectionz/interval_tree.py
+++ b/src/pyutils/collectionz/interval_tree.py
@@ -7,7 +7,7 @@ described by: https://en.wikipedia.org/wiki/Interval_tree.
 from __future__ import annotations
 
 from functools import total_ordering
-from typing import Any, Optional, Union
+from typing import Any, Generator, Optional, Union
 
 from overrides import overrides
 
@@ -18,6 +18,9 @@ Numeric = Union[int, float]
 
 @total_ordering
 class NumericRange(object):
+    """Essentially a tuple of numbers denoting a range with some added
+    helper methods on it."""
+
     def __init__(self, low: Numeric, high: Numeric):
         if low > high:
             temp: Numeric = low
@@ -44,11 +47,8 @@ class NumericRange(object):
 
 
 class AugmentedIntervalTree(bst.BinarySearchTree):
-    def __init__(self):
-        super().__init__()
-
     @staticmethod
-    def assert_value_must_be_range(value: Any) -> None:
+    def _assert_value_must_be_range(value: Any) -> None:
         if not isinstance(value, NumericRange):
             raise Exception(
                 "AugmentedIntervalTree expects to use NumericRanges, see bst for a "
@@ -57,7 +57,7 @@ class AugmentedIntervalTree(bst.BinarySearchTree):
 
     @overrides
     def _on_insert(self, parent: Optional[bst.Node], new: bst.Node) -> None:
-        AugmentedIntervalTree.assert_value_must_be_range(new.value)
+        AugmentedIntervalTree._assert_value_must_be_range(new.value)
         for ancestor in self.parent_path(new):
             assert ancestor
             if new.value.high > ancestor.value.highest_in_subtree:
@@ -73,9 +73,16 @@ class AugmentedIntervalTree(bst.BinarySearchTree):
                 new_highest_candidates.append(parent.right.value.highest_in_subtree)
             parent.value.highest_in_subtree = max(new_highest_candidates)
 
-    def find_one_overlap(self, x: NumericRange):
+    def find_one_overlap(self, to_find: NumericRange) -> Optional[NumericRange]:
         """Identify and return one overlapping node from the tree.
 
+        Args:
+            to_find: the interval with which to find an overlap.
+
+        Returns:
+            An overlapping range from the tree or None if no such
+            ranges exist in the tree at present.
+
         >>> tree = AugmentedIntervalTree()
         >>> tree.insert(NumericRange(20, 24))
         >>> tree.insert(NumericRange(18, 22))
@@ -90,12 +97,15 @@ class AugmentedIntervalTree(bst.BinarySearchTree):
         >>> tree.insert(NumericRange(21, 27))
         >>> tree.find_one_overlap(NumericRange(6, 7))
         1..30
+
         """
-        return self._find_one_overlap(self.root, x)
+        return self._find_one_overlap(self.root, to_find)
 
-    def _find_one_overlap(self, root: bst.Node, x: NumericRange):
+    def _find_one_overlap(
+        self, root: bst.Node, x: NumericRange
+    ) -> Optional[NumericRange]:
         if root is None:
-            return
+            return None
 
         if root.value.overlaps_with(x):
             return root.value
@@ -106,9 +116,20 @@ class AugmentedIntervalTree(bst.BinarySearchTree):
 
         if root.right:
             return self._find_one_overlap(root.right, x)
+        return None
+
+    def find_all_overlaps(
+        self, to_find: NumericRange
+    ) -> Generator[NumericRange, None, None]:
+        """Yields ranges previously added to the tree that overlaps with
+        to_find argument.
+
+        Args:
+            to_find: the interval with which to find all overlaps.
 
-    def find_all_overlaps(self, x: NumericRange):
-        """Yields ranges previously added to the tree that x overlaps with.
+        Returns:
+            A (potentially empty) sequence of all ranges in the tree
+            that overlap with the argument.
 
         >>> tree = AugmentedIntervalTree()
         >>> tree.insert(NumericRange(20, 24))
@@ -137,14 +158,17 @@ class AugmentedIntervalTree(bst.BinarySearchTree):
         18..22
         16..28
         21..27
+
         """
         if self.root is None:
             return
-        yield from self._find_all_overlaps(self.root, x)
+        yield from self._find_all_overlaps(self.root, to_find)
 
-    def _find_all_overlaps(self, root: bst.Node, x: NumericRange):
+    def _find_all_overlaps(
+        self, root: bst.Node, x: NumericRange
+    ) -> Generator[NumericRange, None, None]:
         if root is None:
-            return
+            return None
 
         if root.value.overlaps_with(x):
             yield root.value