Mercurial > urweb
comparison demo/broadcast.ur @ 699:4e260887d8f2
Chat demo
| author | Adam Chlipala <adamc@hcoop.net> |
|---|---|
| date | Sun, 05 Apr 2009 11:48:55 -0400 |
| parents | |
| children | 1a317a707d71 |
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| 698:9b29ce0babb8 | 699:4e260887d8f2 |
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| 1 functor Make(M : sig type t end) = struct | |
| 2 sequence s | |
| 3 table t : {Id : int, Client : client, Channel : channel M.t} | |
| 4 | |
| 5 type topic = int | |
| 6 | |
| 7 val inj : sql_injectable topic = _ | |
| 8 | |
| 9 val create = nextval s | |
| 10 | |
| 11 fun subscribe id = | |
| 12 cli <- self; | |
| 13 ro <- oneOrNoRows (SELECT t.Channel FROM t WHERE t.Id = {[id]} AND t.Client = {[cli]}); | |
| 14 case ro of | |
| 15 None => | |
| 16 ch <- channel; | |
| 17 dml (INSERT INTO t (Id, Client, Channel) VALUES ({[id]}, {[cli]}, {[ch]})); | |
| 18 return ch | |
| 19 | Some r => return r.T.Channel | |
| 20 | |
| 21 fun send id msg = | |
| 22 queryI (SELECT t.Channel FROM t WHERE t.Id = {[id]}) | |
| 23 (fn r => Basis.send r.T.Channel msg) | |
| 24 | |
| 25 fun subscribers id = | |
| 26 r <- oneRow (SELECT COUNT( * ) AS N FROM t WHERE t.Id = {[id]}); | |
| 27 return r.N | |
| 28 end |