X-Git-Url: https://git.xandkar.net/?a=blobdiff_plain;f=003%2Fsrc%2Flife.erl;h=f4b1fe56cd2a6a9a1c415e4aa64f2f21c77a9d9c;hb=704cefa6bfd9bab26938b62c14b47f4803e0cd64;hp=0e953ab40704838ce2e4b069ef7cf11e61b9b3c4;hpb=690cd0adc08a99640423c1bb627ee93aa3341c63;p=cellular-automata.git

diff --git a/003/src/life.erl b/003/src/life.erl
index 0e953ab..f4b1fe5 100644
--- a/003/src/life.erl
+++ b/003/src/life.erl
@@ -7,17 +7,17 @@
 -define(CHAR_ALIVE, 111).  % "o"
 -define(CHAR_BAR,    45).  % "-"
 
--define(INTERVAL, 100).
+-define(GEN_INTERVAL, 100).
 
 
--record(state, {x                 :: non_neg_integer()
-               ,y                 :: non_neg_integer()
-               ,n                 :: non_neg_integer()
-               ,bar               :: string()
-               ,board=array:new() :: array()
-               ,gen_count         :: non_neg_integer()
-               ,gen_duration      :: non_neg_integer()
-               ,print_time        :: non_neg_integer()
+-record(state, {x            :: non_neg_integer()
+               ,y            :: non_neg_integer()
+               ,n            :: pos_integer()
+               ,bar          :: nonempty_string()
+               ,board        :: array()
+               ,gen_count    :: pos_integer()
+               ,gen_duration :: non_neg_integer()
+               ,print_time   :: non_neg_integer()
                }).
 
 
@@ -61,14 +61,22 @@ life_loop(
         end
     ),
 
-    {NewTime, NewBoard} = timer:tc(fun() -> next_generation(X, Y, Board) end),
+    {NewTime, NewBoard} = timer:tc(
+        fun() ->
+            next_generation(X, Y, Board)
+        end
+    ),
+
     NewState = State#state{board        = NewBoard
                           ,gen_count    = GenCount + 1
                           ,gen_duration = NewTime
                           ,print_time   = PrintTime
     },
 
-    timer:sleep(?INTERVAL),
+    NewTimeMil = NewTime / 1000,
+    NextGenDelay = round(?GEN_INTERVAL - NewTimeMil),
+    timer:sleep(NextGenDelay),
+
     life_loop(NewState).
 
 
@@ -89,7 +97,10 @@ do_print_status(Bar, X, Y, N, GenCount, TimeMic, PrintTimeMic) ->
 
 
 do_print_board(Board) ->
-    CharLists = array:to_list(
+    % It seems that just doing a fold should be faster than map + to_list
+    % combo, but, after measuring several times, map + to_list has been
+    % consistently (nearly twice) faster than either foldl or foldr.
+    RowStrings = array:to_list(
         array:map(
             fun(_, Row) ->
                 array:to_list(
@@ -106,10 +117,10 @@ do_print_board(Board) ->
     ),
 
     ok = lists:foreach(
-        fun(CharList) ->
-            ok = io:format("~s~n", [CharList])
+        fun(RowString) ->
+            ok = io:format("~s~n", [RowString])
         end,
-        CharLists
+        RowStrings
     ).