Mercurial > urweb
annotate src/option_key_fn.sml @ 2243:da7d026d1a94
Fix possible formula simplification bug with extra formula' type.
| author | Ziv Scully <ziv@mit.edu> |
|---|---|
| date | Mon, 20 Jul 2015 19:49:13 -0700 |
| parents | 88cc0f44c940 |
| children | e4a7e3cd6f11 |
| rev | line source |
|---|---|
| ziv@2240 | 1 functor OptionKeyFn(K : ORD_KEY) : ORD_KEY = struct |
| ziv@2240 | 2 |
| ziv@2240 | 3 type ord_key = K.ord_key option |
| ziv@2240 | 4 |
| ziv@2240 | 5 val compare = |
| ziv@2240 | 6 fn (NONE, NONE) => EQUAL |
| ziv@2240 | 7 | (NONE, _) => LESS |
| ziv@2240 | 8 | (_, NONE) => GREATER |
| ziv@2240 | 9 | (SOME x, SOME y) => K.compare (x, y) |
| ziv@2240 | 10 |
| ziv@2240 | 11 end |