X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=topics%2Fweek12_list_and_tree_zippers.mdwn;h=3f7ca7a648ff5599d08cfed0d618298c4f513eb2;hp=2f5d5dc66ed291e27c328e1fb1a1e5f9470c8d0d;hb=1d20f8bccfa106e8bd611c366d94734b10750891;hpb=37b002e98a43746b9c92b4002cb564992c024a98
diff --git a/topics/week12_list_and_tree_zippers.mdwn b/topics/week12_list_and_tree_zippers.mdwn
index 2f5d5dc6..3f7ca7a6 100644
--- a/topics/week12_list_and_tree_zippers.mdwn
+++ b/topics/week12_list_and_tree_zippers.mdwn
@@ -213,7 +213,7 @@ siblings of the focussed tree:
Branch (Leaf 2, Leaf 3), ([], [Leaf 4])
-We still need to add the rest of the context. But just computed that
+We still need to add the rest of the context. But we just computed that
context a minute ago. It was ([Leaf 1], []). If we add it here, we get:
Branch (Leaf 2, Leaf 3), ([], [Leaf 4], ([Leaf 1], [])
@@ -223,13 +223,13 @@ Here's the type suggested by this idea:
type context = Root | Context of (tree list) * (tree list) * context
type zipper = tree * context
-We can gloss `Context of (tree list) * (tree list) * context` as
-`Context of (left siblings) * (right siblings) * (context of parent)`.
+We can gloss the triple `(tree list) * (tree list) * context` as
+`(left siblings) * (right siblings) * (context of parent)`.
Here, then, is the full tree zipper we've been looking for:
- (Branch [Leaf 2; Leaf 3],
- Context ([], [Leaf 4], Context ([Leaf 1], [], Root)))
+ (Branch [Leaf 2; Leaf 3],
+ Context ([], [Leaf 4], Context ([Leaf 1], [], Root)))
Just as with the simple list zipper, note that elements that are near
the focussed element in the tree are near the focussed element in the