From 48810c1e60567c4481d1654f522b612f895d1ef5 Mon Sep 17 00:00:00 2001
From: Correl Roush <correl@gmail.com>
Date: Tue, 14 Aug 2012 20:06:40 -0400
Subject: [PATCH] San shoku douko

---
 src/yaku.erl               | 8 ++++++++
 test/riichi_yaku_tests.erl | 8 ++++++++
 2 files changed, 16 insertions(+)

diff --git a/src/yaku.erl b/src/yaku.erl
index b9a6a1d..7750c24 100644
--- a/src/yaku.erl
+++ b/src/yaku.erl
@@ -16,6 +16,7 @@
          itsuu/2,
          chiitoitsu/2,
          san_shoku_doujun/2,
+         san_shoku_douko/2,
          kokushi_musou/2,
          ryuu_iisou/2,
          dai_san_gen/2]).
@@ -132,6 +133,13 @@ san_shoku_doujun(#game{}, #player{hand=#hand{melds=Melds}=Hand}) ->
     Chiis = [M || #meld{type=chii} = M <- Melds],
     lists:any(fun(M) -> san_shoku(M, Hand) end, Chiis).
 
+%% @doc Returns true for a San shoku douko hand
+%%      Hand must contain the same triplet in all three suits
+-spec san_shoku_douko(game(), player()) -> boolean().
+san_shoku_douko(#game{}, #player{hand=#hand{melds=Melds}=Hand}) ->
+    Pons = [M || #meld{type=pon} = M <- Melds],
+    lists:any(fun(M) -> san_shoku(M, Hand) end, Pons).
+
 %% @doc Returns true for a 7-pair hand.
 -spec chiitoitsu(game(), player()) -> boolean().
 chiitoitsu(#game{}, #player{hand=#hand{tiles=[], melds=Melds}})
diff --git a/test/riichi_yaku_tests.erl b/test/riichi_yaku_tests.erl
index 37775a5..7955c05 100644
--- a/test/riichi_yaku_tests.erl
+++ b/test/riichi_yaku_tests.erl
@@ -68,6 +68,14 @@ san_shoku_doujun_test() ->
                         #meld{type=chii, tiles=[#tile{suit=man, value=V} || V <- [6,7,8]]}]},
     ?assertEqual(true, yaku:san_shoku_doujun(#game{}, #player{hand=Hand, drawn={tsumo, #tile{suit=dragon, value=red}}})).
 
+san_shoku_douko_test() ->
+    Hand = #hand{melds=[#meld{type=pair, tiles=lists:duplicate(2, #tile{suit=sou, value=8})},
+                        #meld{type=pon, tiles=[#tile{suit=sou, value=V} || V <- [1,1,1]]},
+                        #meld{type=pon, tiles=[#tile{suit=man, value=V} || V <- [1,1,1]]},
+                        #meld{type=pon, tiles=[#tile{suit=pin, value=V} || V <- [1,1,1]]},
+                        #meld{type=chii, tiles=[#tile{suit=man, value=V} || V <- [6,7,8]]}]},
+    ?assertEqual(true, yaku:san_shoku_douko(#game{}, #player{hand=Hand, drawn={tsumo, #tile{suit=dragon, value=red}}})).
+
 chiitoitsu_test() ->
     Hand = #hand{melds=[#meld{type=pair, tiles=lists:duplicate(2, #tile{suit=pin, value=V})} || V <- lists:seq(1,7)]},
     ?assertEqual(true, yaku:chiitoitsu(#game{}, #player{hand=Hand})).