1 files changed, 74 insertions, 0 deletions
diff --git a/third_party/rust/jsparagus/jsparagus/utils.py b/third_party/rust/jsparagus/jsparagus/utils.py
new file mode 100644
index 0000000000..f3ecba2472
--- /dev/null
+++ b/third_party/rust/jsparagus/jsparagus/utils.py
@@ -0,0 +1,74 @@
+"""List of functions which are useful in many places."""
+
+import sys
+import typing
+
+
+T = typing.TypeVar("T")
+U = typing.TypeVar("U")
+
+
+def keep_until(
+        iterable: typing.Iterable[T],
+        pred: typing.Callable[[T], bool]
+) -> typing.Iterable[T]:
+    """Filter an iterable generator or list and keep all elements until the first
+    time the predicate becomes true, including the element where the predicate
+    is true. All elements after are skipped."""
+    for e in iterable:
+        yield e
+        if pred(e):
+            return
+
+
+def split(
+        iterable: typing.Iterable[T],
+        pred: typing.Callable[[T], bool]
+) -> typing.Tuple[typing.List[T], typing.List[T]]:
+    """Given a predicate, split the input iterator into a tuple of 2 list. A first
+    list which satisfy the predicate and a second list which does not."""
+    yes = []
+    no = []
+    for e in iterable:
+        if pred(e):
+            yes.append(e)
+        else:
+            no.append(e)
+    return yes, no
+
+
+def consume(iterator: typing.Iterable[T], progress: bool) -> None:
+    """Drain the iterator. If progress is true, print dots on stdout."""
+    i = 0
+    to_feed = str(i)
+    try:
+        for _ in iterator:
+            if progress:
+                if len(to_feed) > 0:
+                    sys.stdout.write(to_feed[0])
+                    to_feed = to_feed[1:]
+                else:
+                    sys.stdout.write(".")
+                i += 1
+                if i % 100 == 0:
+                    sys.stdout.write("\n")
+                    to_feed = str(i)
+                sys.stdout.flush()
+    finally:
+        if progress and i != 0:
+            sys.stdout.write("\n")
+            sys.stdout.flush()
+
+
+class default_id_dict(dict, typing.Mapping[T, T]):
+    def __missing__(self, key) -> T:
+        return key
+
+
+class default_fwd_dict(dict, typing.Mapping[T, U]):
+    def __init__(self, fwd: typing.Mapping[T, U]):
+        super().__init__()
+        self.fwd = fwd
+
+    def __missing__(self, key: T) -> U:
+        return self.fwd[key]