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| author | Joey Hess <joeyh@joeyh.name> | 2015-01-25 14:45:14 -0400 |
|---|---|---|
| committer | Joey Hess <joeyh@joeyh.name> | 2015-01-25 14:47:57 -0400 |
| commit | e9d5d9aff1cc2046149d3e5dcd9f4ef0f2a334a1 (patch) | |
| tree | 24b5bc62ac3851c317023d79080eb0ed8176cdba /doc/todo | |
| parent | 334abae31277b9f47b85813d7b2fd783e5b3b12d (diff) | |
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.
Diffstat (limited to 'doc/todo')
| -rw-r--r-- | doc/todo/RevertableProperty_with_NoInfo.mdwn | 18 |
1 files changed, 18 insertions, 0 deletions
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. |