From 85b5ac312b8dfc2f0ecc35d1a64b501ef5bde6ea Mon Sep 17 00:00:00 2001
From: Lucian Mogosanu <lucian.mogosanu@gmail.com>
Date: Wed, 17 Dec 2014 17:24:38 +0200
Subject: [PATCH] ZXS: Machine, RAM: Add utility functions

---
 src/ZXS/Decode.hs  |    1 +
 src/ZXS/Machine.hs |    9 +++++++++
 src/ZXS/RAM.hs     |    3 +++
 3 files changed, 13 insertions(+)

diff --git a/src/ZXS/Decode.hs b/src/ZXS/Decode.hs
index f73f31a..1b21657 100644
--- a/src/ZXS/Decode.hs
+++ b/src/ZXS/Decode.hs
@@ -15,6 +15,7 @@ import Z80.Microcode
 import ZXS.Machine
 import ZXS.Fetch
 
+-- TODO: update this for prefixed opcodes
 decode :: ZXS Instruction
 decode = do
   b <- fetch
diff --git a/src/ZXS/Machine.hs b/src/ZXS/Machine.hs
index c098c64..3eaeff0 100644
--- a/src/ZXS/Machine.hs
+++ b/src/ZXS/Machine.hs
@@ -18,6 +18,15 @@ data Spectrum = Spectrum
 newtype ZXST m a = ZXST { unZXST :: StateT Spectrum m a }
   deriving (MonadState Spectrum, Monad, Functor, Applicative, MonadIO)
 
+runZXST :: ZXST m a -> Spectrum -> m (a, Spectrum)
+runZXST zxst state = runStateT (unZXST zxst) state
+
+evalZXST :: Monad m => ZXST m a -> Spectrum -> m a
+evalZXST zxst state = runZXST zxst state >>= return . fst
+
+execZXST :: Monad m => ZXST m a -> Spectrum -> m Spectrum
+execZXST zxst state = runZXST zxst state >>= return . snd
+
 -- for now we "fall back" to IO as the default inner monad
 type ZXS a = ZXST IO a
 
diff --git a/src/ZXS/RAM.hs b/src/ZXS/RAM.hs
index aaf994c..dcfad76 100644
--- a/src/ZXS/RAM.hs
+++ b/src/ZXS/RAM.hs
@@ -45,3 +45,6 @@ romMem = newListArray (0x0000, 0x3fff) $ repeat 0
 
 mainMem :: IO RAM
 mainMem = newListArray (0x5ccb, 0xff57) $ repeat 0
+
+newRAM :: (Word16, Word16) -> IO RAM
+newRAM (start, end) = newListArray (start, end) $ repeat 0
-- 
1.7.10.4