diff options
| author |  Benjamin Barenblat <bbaren@mit.edu> | 2015-12-23 16:01:51 -0500 |
|---|---|---|
| committer | Benjamin Barenblat <bbaren@mit.edu> | 2015-12-23 16:01:51 -0500 |
| commit | 3d3886672433f0775f772d8d2ee47c5f5e0bc745 (patch) | |
| tree | 072d171c17d92a6696024256c4b2f5aaa760df35 /src/option_key_fn.sml | |
| parent | bf037ce78c2c76a34ecca0fb8bafa5d5be38968a (diff) | |
| parent | 4be7962adf740a35222bfd99608c04329a802a04 (diff) | |
Merge branch 'upstream' into dfsg_clean20151220+dfsg
Diffstat (limited to 'src/option_key_fn.sml')
| -rw-r--r-- | src/option_key_fn.sml | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/option_key_fn.sml b/src/option_key_fn.sml new file mode 100644 index 00000000..27ba9138 --- /dev/null +++ b/src/option_key_fn.sml @@ -0,0 +1,12 @@ +functor OptionKeyFn(K : ORD_KEY) + : ORD_KEY where type ord_key = K.ord_key option = struct + +type ord_key = K.ord_key option + +val compare = + fn (NONE, NONE) => EQUAL + | (NONE, _) => LESS + | (_, NONE) => GREATER + | (SOME x, SOME y) => K.compare (x, y) + +end |