Time for an 2014 update…

Task/Pi/Lua/pi.lua

@@ -0,0 +1,41 @@
+a = {}
+n = 1000
+len = math.modf( 10 * n / 3 )
+
+for j = 1, len do
+    a[j] = 2
+end
+nines = 0
+predigit = 0
+for j = 1, n do
+    q = 0
+    for i = len, 1, -1 do
+        x = 10 * a[i] + q * i
+        a[i] = math.fmod( x, 2 * i - 1 )
+        q = math.modf( x / ( 2 * i - 1 ) )
+    end
+    a[1] = math.fmod( q, 10 )
+    q = math.modf( q / 10 )
+    if q == 9 then
+        nines = nines + 1
+    else
+        if q == 10 then
+            io.write( predigit + 1 )
+            for k = 1, nines do
+                io.write(0)
+            end
+            predigit = 0
+            nines = 0
+        else
+            io.write( predigit )
+            predigit = q
+            if nines ~= 0 then
+                for k = 1, nines do
+                    io.write( 9 )
+                end
+                nines = 0
+            end
+        end
+    end
+end
+print( predigit )