snapshot of https://github.com/zulip/zulip.git @ 48c69911c7dd4e03b20552eb3bd77ad8151c1357 (2026-09-15)

zerver/lib/narrow_helpers.py

@@ -0,0 +1,63 @@
+"""
+This module partly exists to prevent circular dependencies.
+
+It also isolates some fairly yucky code related to the fact
+that we have to support two formats of narrow specifications
+from users:
+
+    legacy:
+        [["stream", "devel"], ["is", mentioned"]
+
+    modern:
+        [
+            {"operator": "stream", "operand": "devel", "negated": "false"},
+            {"operator": "is", "operand": "mentioned", "negated": "false"},
+        ]
+
+    And then on top of that, we want to represent narrow
+    specification internally as dataclasses.
+"""
+
+import os
+from collections.abc import Collection, Sequence
+from dataclasses import dataclass, field
+
+from django.conf import settings
+
+
+@dataclass
+class NarrowTerm:
+    operator: str
+    operand: str | int | list[int]
+    negated: bool
+
+
+@dataclass
+class NeverNegatedNarrowTerm(NarrowTerm):
+    negated: bool = field(default=False, init=False)
+    operand: str
+
+
+def narrow_dataclasses_from_tuples(
+    tups: Collection[Sequence[str]],
+) -> Collection[NeverNegatedNarrowTerm]:
+    """
+    This method assumes that the callers are in our event-handling codepath, and
+    therefore as of summer 2023, they do not yet support the "negated" flag.
+    """
+    return [NeverNegatedNarrowTerm(operator=tup[0], operand=tup[1]) for tup in tups]
+
+
+stop_words_list: list[str] | None = None
+
+
+def read_stop_words() -> list[str]:
+    global stop_words_list
+    if stop_words_list is None:
+        file_path = os.path.join(
+            settings.DEPLOY_ROOT, "puppet/zulip/files/postgresql/zulip_english.stop"
+        )
+        with open(file_path) as f:
+            stop_words_list = f.read().splitlines()
+
+    return stop_words_list