Merge branch 'master' of https://github.com/jack-pappas/ArrayAccessBench

Author: logicchains

Diff for: FS4.fs

@@ -0,0 +1,64 @@
+let [<Literal>] NUM_RECORDS =
+    // F# didn't support constant folding until F# 3.1, so hard-code this constant for now.
+    22200000 // 50 * 1000 * 444
+
+[<Struct>]
+type FSMemTrade =
+    val mutable TradeId : int64;
+    val mutable ClientId : int64;
+    val mutable VenueId : int32;
+    val mutable InstrumentCode : int32;
+    val mutable Price : int64;
+    val mutable Quantity : int64;
+    val mutable Side : char
+
+let trades =
+    Array.init NUM_RECORDS <| fun i ->
+        // In C# and F#, struct fields are initialized by default to the 'default' value for the field type;
+        // this means you only need to set fields which need to be set to a non-default value.
+        FSMemTrade (
+            Side = 'a')
+
+let initTrades () =
+    printfn "initiating trades"
+
+    for i = 0 to NUM_RECORDS - 1 do
+        trades.[i] <-
+            let long_i = int64 i
+            FSMemTrade (
+                TradeId = long_i,
+                ClientId = 1L,
+                VenueId = 123,
+                InstrumentCode = 321,
+                Price = long_i,
+                Quantity = long_i,
+                Side = if (i % 2 = 0) then 'S' else 'B')
+
+let perfRun n =
+    let mutable buyCost = 0L
+    let mutable sellCost = 0L
+
+    let watch = System.Diagnostics.Stopwatch.StartNew ()
+    
+    initTrades ()
+
+    for i = 0 to NUM_RECORDS - 1 do
+        let cost = trades.[i].Price * trades.[i].Quantity
+        if trades.[i].Side = 'B' then
+            buyCost <- buyCost + cost
+        else
+            sellCost <- sellCost + cost
+
+    watch.Stop ()
+
+    let duration = int watch.Elapsed.TotalMilliseconds
+    printfn "%d - duration %d ms" n duration
+    printfn "buyCost = %O sellCost = %O" buyCost sellCost
+
+[<EntryPoint>]
+let main args =
+    for i = 0 to 4 do
+        System.GC.Collect ()
+        perfRun i
+
+    0 // Exit code