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-rw-r--r--src/prompt_toolkit/filters/utils.py41
1 files changed, 41 insertions, 0 deletions
diff --git a/src/prompt_toolkit/filters/utils.py b/src/prompt_toolkit/filters/utils.py
new file mode 100644
index 0000000..bac85ba
--- /dev/null
+++ b/src/prompt_toolkit/filters/utils.py
@@ -0,0 +1,41 @@
+from __future__ import annotations
+
+from .base import Always, Filter, FilterOrBool, Never
+
+__all__ = [
+ "to_filter",
+ "is_true",
+]
+
+
+_always = Always()
+_never = Never()
+
+
+_bool_to_filter: dict[bool, Filter] = {
+ True: _always,
+ False: _never,
+}
+
+
+def to_filter(bool_or_filter: FilterOrBool) -> Filter:
+ """
+ Accept both booleans and Filters as input and
+ turn it into a Filter.
+ """
+ if isinstance(bool_or_filter, bool):
+ return _bool_to_filter[bool_or_filter]
+
+ if isinstance(bool_or_filter, Filter):
+ return bool_or_filter
+
+ raise TypeError("Expecting a bool or a Filter instance. Got %r" % bool_or_filter)
+
+
+def is_true(value: FilterOrBool) -> bool:
+ """
+ Test whether `value` is True. In case of a Filter, call it.
+
+ :param value: Boolean or `Filter` instance.
+ """
+ return to_filter(value)()