first commit

swingmusic/utils/bisection.py

@@ -0,0 +1,46 @@
+from typing import TypeVar
+
+T = TypeVar("T")
+
+
+def use_bisection(
+    source: list[T], key: str, queries: list[str], limit: int = -1
+) -> list[T | None]:
+    """
+    Uses bisection to find a list of items in another list.
+
+    Returns a list of found items with `None` items being not found items.
+    """
+
+    def find(query: str):
+        left = 0
+        right = len(source) - 1
+
+        while left <= right:
+            mid = (left + right) // 2
+            if source[mid].__getattribute__(key) == query:
+                return source[mid]
+            elif source[mid].__getattribute__(key) > query:
+                right = mid - 1
+            else:
+                left = mid + 1
+
+        return None
+
+    if len(source) == 0:
+        return []
+
+    results = []
+
+    for query in queries:
+        res = find(query)
+
+        if res is None:
+            continue
+
+        results.append(res)
+
+        if limit != -1 and len(results) >= limit:
+            break
+
+    return results