From 1a1b8995917d77e30c6ab9768bfac08221c6fad4 Mon Sep 17 00:00:00 2001
From: ST John <st--@users.noreply.github.com>
Date: Thu, 14 Apr 2022 09:01:21 +0300
Subject: [PATCH] add comment

---
 src/transform/transform.jl | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/transform/transform.jl b/src/transform/transform.jl
index 40ce8c058..c7da2729d 100644
--- a/src/transform/transform.jl
+++ b/src/transform/transform.jl
@@ -5,6 +5,9 @@ Abstract type defining a transformation of the input.
 """
 abstract type Transform end
 
+# We introduce our own _map for Transform so that we can work around
+# https://github.com/FluxML/Zygote.jl/issues/646 and define our own pullback
+# (see zygoterules.jl)
 Base.map(t::Transform, x::AbstractVector) = _map(t, x)
 _map(t::Transform, x::AbstractVector) = t.(x)