Add parse_regex_flags

2 files changed, 26 insertions, 0 deletions

diff --git a/patternutils/types.py b/patternutils/types.py
index 6b2a5ac..cbab184 100644
--- a/patternutils/types.py
+++ b/patternutils/types.py
@@ -13,4 +13,5 @@ PredefinedExtensions = Literal[TemplateExtensions, RegexExtensions]
 
 CommandNames = Literal[PlainCommands, TemplateCommands, RegexCommands]
 
+RegexFlags = Literal["ascii", "a", "ignorecase", "i", "multiline", "m", "dotall", "s"]
 TemplatePrefer = Optional[Literal["global", "command"]]
diff --git a/patternutils/utils.py b/patternutils/utils.py
index 22d4123..89b7a05 100644
--- a/patternutils/utils.py
+++ b/patternutils/utils.py
@@ -1,9 +1,13 @@
 import json
 import os
+import re
+from collections.abc import Container
 from typing import Any, Generator, Optional, overload
 
 import click
 
+from patternutils.types import RegexFlags
+
 
 def max_procs() -> int:
     """Returns the number of CPU cores available, or 1 if unavailable."""
@@ -121,3 +125,24 @@ def walk(
     except FileNotFoundError:
         click.secho(f"Directory not found: {directory}", fg="red", err=True)
         raise SystemExit(1)
+
+
+def parse_regex_flags(flags: Container[RegexFlags]) -> int:
+    concrete_flags = re.NOFLAG
+
+    if "ascii" in flags or "a" in flags:
+        concrete_flags |= re.ASCII
+
+    if "ignorecase" in flags or "i" in flags:
+        concrete_flags |= re.IGNORECASE
+
+    if "multiline" in flags or "m" in flags:
+        concrete_flags |= re.MULTILINE
+
+    if "dotall" in flags or "s" in flags:
+        concrete_flags |= re.DOTALL
+
+    if "verbose" in flags or "x" in flags:
+        concrete_flags |= re.VERBOSE
+
+    return concrete_flags