From e9d5d9aff1cc2046149d3e5dcd9f4ef0f2a334a1 Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Sun, 25 Jan 2015 14:45:14 -0400 Subject: remove toSimpleProp It didn't do what I thought it did with a RevertableProperty; it always returned Nothing because even if the input properties to are NoInfo, it casts them to HasInfo. Even if it had worked, it lost type safety. Better to export the Property NoInfo that is used in a RevertableProperty, so it can be used directly. --- doc/todo/RevertableProperty_with_NoInfo.mdwn | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 doc/todo/RevertableProperty_with_NoInfo.mdwn (limited to 'doc') diff --git a/doc/todo/RevertableProperty_with_NoInfo.mdwn b/doc/todo/RevertableProperty_with_NoInfo.mdwn new file mode 100644 index 00000000..3b4a61a9 --- /dev/null +++ b/doc/todo/RevertableProperty_with_NoInfo.mdwn @@ -0,0 +1,18 @@ +Currently, a RevertableProperty's Properties always both HasInfo. This +means that if a Property NoInfo is updated to be a RevertableProperty, and +someplace called ensureProperty on it, that will refuse to compile. + +The workaround is generally to export the original NoInfo property under +a different name, so it can still be used with ensureProperty. + +This could be fixed: + + data RevertableProperty i1 i2 where + RProp :: Property i1 -> Property i2 -> RevertableProperty i1 i2 + +However, needing to write "RevertableProperty HasInfo NoInfo" is quite +a mouthful! + +Since only 2 places in the propellor source code currently need to deal +with this, it doesn't currently seem worth making the change, unless a less +intrusive way can be found. -- cgit v1.3-2-g0d8e