diff --git a/Control/Monad/Imperative.hs b/Control/Monad/Imperative.hs
new file mode 100644
--- /dev/null
+++ b/Control/Monad/Imperative.hs
@@ -0,0 +1,28 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module : Control.Monad.Imperative
+-- Author : Matthew Mirman ( mmirman@andrew.cmu.edu )
+-- Stability : experimental
+-- Portability : portable
+-- Description : A front end for the ImperativeMonad
+-- License : GNUv3
+--
+-- Copyright (C) 2012 Matthew Mirman
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation, either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program. If not, see
+
+module Control.Monad.Imperative (module X) where
+
+import Control.Monad.Imperative.ImperativeMonad as X
+import Control.Monad.Imperative.ImperativeOperators as X
diff --git a/Control/Monad/Imperative/ImperativeMonad.hs b/Control/Monad/Imperative/ImperativeMonad.hs
new file mode 100644
--- /dev/null
+++ b/Control/Monad/Imperative/ImperativeMonad.hs
@@ -0,0 +1,149 @@
+{-# LANGUAGE
+ GADTs,
+ EmptyDataDecls
+ #-}
+
+-----------------------------------------------------------------------------
+-- |
+-- Module : Control.Monad.Imperative.ImperativeMonad
+-- Author : Matthew Mirman ( mmirman@andrew.cmu.edu )
+-- Stability : experimental
+-- Portability : portable
+-- Description : A module for Imperative haskell code.
+-- License : GNUv3
+--
+-- Copyright (C) 2012 Matthew Mirman
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation, either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program. If not, see
+
+module Control.Monad.Imperative.ImperativeMonad
+ ( modifyOp
+ , if'
+ , for
+ , break
+ , continue
+ , returnV
+ , function
+ , auto
+ , runImperative
+ , liftOp2
+ , prim
+ , returnF
+ , (=:)
+ , (&)
+ ) where
+
+import Prelude hiding (break)
+import Control.Monad.Cont
+import Control.Monad.Reader
+import Data.IORef
+
+data Var
+data Val
+data Comp
+
+data Control r = InFunction (r -> ContT r IO ())
+ | InLoop { controlBreak::MIO r ()
+ , controlContinue::MIO r ()
+ , controlReturn:: r -> MIO r ()
+ }
+
+returnF :: V a b b -> MIO b b
+returnF v = do
+ v' <- val v
+ a <- ask
+ case a of
+ InLoop _ _ ret -> ret v'
+ InFunction ret -> lift $ ret v'
+ return v'
+
+runImperative :: MIO a a -> IO a
+runImperative foo = runContT (callCC $ \ret -> runReaderT foo $ InFunction ret) return
+
+function :: MIO a a -> MIO b a
+function = liftIO . runImperative
+
+break :: MIO a ()
+break = do
+ a <- ask
+ case a of
+ InLoop br _ _ -> br
+ _ -> return ()
+
+continue :: MIO a ()
+continue = do
+ a <- ask
+ case a of
+ InLoop _ con _ -> con
+ _ -> return ()
+
+type MIO r a = ReaderT (Control r) (ContT r IO) a
+
+data V b r a where
+ R :: IORef a -> V Var r a
+ L :: a -> V Val r a
+ C :: MIO r (V b r a) -> V Comp r a
+
+returnV a = returnF a >> return ()
+
+val :: V b r a -> MIO r a
+val v = case v of
+ R r -> liftIO $ readIORef r
+ L v -> return v
+ C m -> val =<< m
+
+(&) :: V Var r a -> V Var s a
+(&) (R a) = R a
+
+auto :: a -> MIO r (V Var r a)
+auto a = do
+ r <- liftIO $ newIORef a
+ return $ R r
+
+prim :: a -> V Val r a
+prim a = L a
+
+infixr 0 =:
+
+(=:) :: V Var r a -> V b r a -> MIO r ()
+(=:) (R ar) br = do
+ b <- val br
+ liftIO $ writeIORef ar b
+
+for :: (MIO r irr1, V b r Bool, MIO r irr2) -> MIO r () -> MIO r ()
+for (init, check, incr) body = init >> for'
+ where for' = do
+ do_comp <- val check
+ when do_comp $ callCC $ \break_foo -> do
+ callCC $ \continue_foo -> do
+ flip withReaderT body $ \inbod ->
+ InLoop (break_foo ()) (continue_foo ()) (controlReturn inbod)
+ incr
+ for'
+
+if' :: V b r Bool -> MIO r () -> MIO r ()
+if' b m = do
+ v <- val b
+ when v m
+
+modifyOp :: (a->b->a) -> V Var r a -> V k r b -> MIO r ()
+modifyOp op (R ar) br = do
+ b <- val br
+ liftIO $ modifyIORef ar (\v -> op v b)
+
+liftOp2 :: (t -> t' -> a) -> V b r t -> V b' r t' -> V Comp r a
+liftOp2 foo ar br = C $ do
+ a <- val ar
+ b <- val br
+ return $ prim $ foo a b
diff --git a/Control/Monad/Imperative/ImperativeOperators.hs b/Control/Monad/Imperative/ImperativeOperators.hs
new file mode 100644
--- /dev/null
+++ b/Control/Monad/Imperative/ImperativeOperators.hs
@@ -0,0 +1,41 @@
+{-# LANGUAGE
+ NoMonomorphismRestriction
+ #-}
+-----------------------------------------------------------------------------
+-- |
+-- Module : Control.Monad.Imperative.ImperativeOperators
+-- Author : Matthew Mirman ( mmirman@andrew.cmu.edu )
+-- Stability : experimental
+-- Portability : portable
+-- Description : Some predefined operators for the imperative monad.
+-- License : GNUv3
+--
+-- Copyright (C) 2012 Matthew Mirman
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation, either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program. If not, see
+
+module Control.Monad.Imperative.ImperativeOperators where
+
+import Control.Monad.Imperative.ImperativeMonad
+
+
+(+=:) = modifyOp (+)
+(*=:) = modifyOp (*)
+(-=:) = modifyOp (-)
+(%=:) = modifyOp (mod)
+
+(<.) = liftOp2 (<)
+(>.) = liftOp2 (>)
+(+.) = liftOp2 (+)
+(*.) = liftOp2 (*)
diff --git a/ImperativeHaskell.cabal b/ImperativeHaskell.cabal
new file mode 100644
--- /dev/null
+++ b/ImperativeHaskell.cabal
@@ -0,0 +1,43 @@
+Name: ImperativeHaskell
+Version: 0.1.0.0
+Description: A monad that uses GADTs and continuations
+ to replicate what it is like to program
+ in an imperative language like C or Java
+ with "return", "for", "break", "continue",
+ and mutable references.
+
+Homepage: https://github.com/mmirman/ImperativeHaskell
+
+License: GPL-3
+
+License-file: LICENSE
+
+Author: Matthew Mirman
+
+Maintainer: Matthew Mirman
+
+Category: Control
+
+Build-type: Simple
+
+Cabal-version: >=1.6
+
+Library
+
+ Build-depends: base >= 4.0 && < 5.0,
+ mtl > 2.0 && < 3.0
+
+ Exposed-modules: Control.Monad.Imperative,
+ Control.Monad.Imperative.ImperativeMonad,
+ Control.Monad.Imperative.ImperativeOperators
+
+ Extensions: GADTs, EmptyDataDecls, NoMonomorphismRestriction
+
+Executable test1
+ Main-is: Main.hs
+ Other-Modules: Control.Monad.Imperative
+ Build-depends: base
+
+source-repository head
+ type: git
+ location: git://github.com/mmirman/ImperativeHaskell.git
diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,320 @@
+ GNU GENERAL PUBLIC LICENSE
+ Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc.
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ Preamble
+
+ The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
+
+ The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works. By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users. We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors. You can apply it to
+your programs, too.
+
+ When we speak of free software, we are referring to freedom, not
+price. Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+them if you wish), that you receive source code or can get it if you
+want it, that you can change the software or use pieces of it in new
+free programs, and that you know you can do these things.
+
+ To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights. Therefore, you have
+certain responsibilities if you distribute copies of the software, or if
+you modify it: responsibilities to respect the freedom of others.
+
+ For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received. You must make sure that they, too, receive
+or can get the source code. And you must show them these terms so they
+know their rights.
+
+ Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
+
+ For the developers' and authors' protection, the GPL clearly explains
+that there is no warranty for this free software. For both users' and
+authors' sake, the GPL requires that modified versions be marked as
+changed, so that their problems will not be attributed erroneously to
+authors of previous versions.
+
+ Some devices are designed to deny users access to install or run
+modified versions of the software inside them, although the manufacturer
+can do so. This is fundamentally incompatible with the aim of
+protecting users' freedom to change the software. The systematic
+pattern of such abuse occurs in the area of products for individuals to
+use, which is precisely where it is most unacceptable. Therefore, we
+have designed this version of the GPL to prohibit the practice for those
+products. If such problems arise substantially in other domains, we
+stand ready to extend this provision to those domains in future versions
+of the GPL, as needed to protect the freedom of users.
+
+ Finally, every program is threatened constantly by software patents.
+States should not allow patents to restrict development and use of
+software on general-purpose computers, but in those that do, we wish to
+avoid the special danger that patents applied to a free program could
+make it effectively proprietary. To prevent this, the GPL assures that
+patents cannot be used to render the program non-free.
+
+ The precise terms and conditions for copying, distribution and
+modification follow.
+
+ TERMS AND CONDITIONS
+
+ 0. Definitions.
+
+ "This License" refers to version 3 of the GNU General Public License.
+
+ "Copyright" also means copyright-like laws that apply to other kinds of
+works, such as semiconductor masks.
+
+ "The Program" refers to any copyrightable work licensed under this
+License. Each licensee is addressed as "you". "Licensees" and
+"recipients" may be individuals or organizations.
+
+ To "modify" a work means to copy from or adapt all or part of the work
+in a fashion requiring copyright permission, other than the making of an
+exact copy. The resulting work is called a "modified version" of the
+earlier work or a work "based on" the earlier work.
+
+ A "covered work" means either the unmodified Program or a work based
+on the Program.
+
+ To "propagate" a work means to do anything with it that, without
+permission, would make you directly or secondarily liable for
+infringement under applicable copyright law, except executing it on a
+computer or modifying a private copy. Propagation includes copying,
+distribution (with or without modification), making available to the
+public, and in some countries other activities as well.
+
+ To "convey" a work means any kind of propagation that enables other
+parties to make or receive copies. Mere interaction with a user through
+a computer network, with no transfer of a copy, is not conveying.
+
+ An interactive user interface displays "Appropriate Legal Notices"
+to the extent that it includes a convenient and prominently visible
+feature that (1) displays an appropriate copyright notice, and (2)
+tells the user that there is no warranty for the work (except to the
+extent that warranties are provided), that licensees may convey the
+work under this License, and how to view a copy of this License. If
+the interface presents a list of user commands or options, such as a
+menu, a prominent item in the list meets this criterion.
+
+ 1. Source Code.
+
+ The "source code" for a work means the preferred form of the work
+for making modifications to it. "Object code" means any non-source
+form of a work.
+
+ A "Standard Interface" means an interface that either is an official
+standard defined by a recognized standards body, or, in the case of
+interfaces specified for a particular programming language, one that
+is widely used among developers working in that language.
+
+ The "System Libraries" of an executable work include anything, other
+than the work as a whole, that (a) is included in the normal form of
+packaging a Major Component, but which is not part of that Major
+Component, and (b) serves only to enable use of the work with that
+Major "Major Component", in this context, means a major essential component
+(kernel, window system, and so on) of the specific operating system
+(if any) on which the executable work r, it does not include the work's
+System Libraries, or general-purpose tools or generally available free
+programs which are used unmodified in performing those activities but
+which are not part of the work. For eose
+subprograms and other parts of the work.
+
+ The Corresponding Source need not include anything that users
+can regenerate automatically from other parts of the work.
+
+ 2. Basic Permissions.
+
+ All rights gran unmodified Program. The output from running a
+covered work is covered by this
+
+ You may make, run and propagate covered works that you do not
+convey, without conditions so long as your license otherwise remainyou, or proively on your behalf, under your direction
+and control, on terms that prohibit them from making any copies of
+your copyrighted material outside their relationship with you.
+
+ Conveying under any otherg obligations under article
+11 of the WIPO copyright treaty adopted on 20 December 1996, or
+similar laws prohibiting or restricting circumvention of such
+measures.
+
+ When you convey a covered work, you waive any k's
+users, your or third parties' legal rights to forbidsly and
+appropriately publish on each copy an appropriate copyright notice;
+keep intact all notices stating that this License and any
+non-permissive terms amay convey a work based on the Program, or the modifications to
+produce it from the Program, in the form of source code under the
+terms of section 4, provided that you also meet all of these conditions:
+
+ a) T
+ "keep intact all notices".
+
+ c) You must license the entire work, as a whole, under this
+ License to anyone who comes into possession of a copy. This
+ License will therefore apply, along with any ae work has interactive user interfaces, each must display
+ Appropriate Legal Notices; however, if the Program has interactive
+ interfaces that do not display Apered work with other separate and independent
+regate" if the compilation and its resulting copyright are not
+used to limit the access or legal rights of the c the other
+parts of the aggregate.
+
+ 6. Conveying Non-Source Forms.
+
+ You may convey a covered woricensware interchange.
+
+ b) Convey the object code in, or embodied in, a physical product
+ (including a physical distribution medium), accompanied by a
+ written offer, valid for at least three years and ly used for software interchange, for a price no
+ more than your reasonable cost of physically performing this
+ conveying of source, or (2) access to copy the
+ Correes of the object code with a copy of tection 6b.
+
+ d) Convey the object code by offering access from a designated
+ place (gratis or for a charge),quire recipients to copy the
+ Corresponding Source along with the object code. If the place toequival available for as long as needed to satisfy these requirements.
+
+ e) Convey the object code using peer-to-peer transmission, provided
+ you inform other peers where the object code and Corresponding
+her (1) a "consumer product", which means any
+tangible personal property which is normally used for personal, family,
+or household purposes, or (2) anything designed or sold for incorporation
+into a dwelling. Inway in which the particular user
+ly significant mode of use of the product.
+
+ "Installation Information" for a User Product means any methods,
+procedures, authorization keys, or other information required to insbject code work under this section in, or with, or
+specifically for use in, a User Product, and the conveying occurs as
+part of a transaction in which the right of possession and use of the
+User Product is transf ability to install
+modified object code on the User Product (for example, the work has
+been installed in ROM).
+
+ The requirement to provide Installation Information does not include a
+requirement to continue totwork or violates the rules and
+protocols for communica available to the public in
+source code form), and must require no special password or key for
+unpacking, reading or copying.
+
+ 7. Additional Terms.
+
+ "Addpart of the Program, that part may be used separately
+under those permissions, but the entire Program remains governed by
+this License without regard to the additional permissions.
+
+ When you convey a copy of a work,
+for which you have or can give appropriate copyright permission.
+
+ Notwithstanding any other provision of this License, for material you
+add to a covered work, you may (if authorized by the copyright f thaterial or in the Apt from the original version; or
+
+ d) Limiting the use for publicity purposes of names of licensors or
+ authors of the material; or
+
+ e) Declining to grant rights under trademark law fsumptions directly impose on
+ those licensors and authors.
+
+ All other non-permissive additional terms are considered "further
+restrictions" within the meaning of section 10. If the Program as you
+received itmaterial governed by the terms
+of that license document, provided that the further restriction does
+not survive such relicensing or conveying.
+
+ If you add terms to a covered work in accord with this section, yo
+the above requirements apply either way.
+
+ 8. Termination.
+
+ You may not propagate or rights under
+this License (including any patent licenses granted under the third
+paragraph of section 11).
+
+ However, if y particular copyright holder is
+reinstated permanently if the copyright holder notifies you of the
+violation by some reasonable means, this is the first time you have
+received notice of violation of this License en terminated and not permanently
+reinstated, you do not qualify to receive new licenses for the same
+material under section 10.
+
+ 9. Acceptance Not Required for Having Copies.
+
+ You are not required to accepy agate or
+modify any covered work. These actions infringe copyright if you do
+not accept this License. Therefore, by ecipients.
+
+ Each time you convey a covered work, the recipient automatically
+receives a licey transaction, each party to that
+transaction who receives a copy of the work also receives whatever
+licenses to the work the party's predecessor in interest had or could
+give under the previous paragraph, plus a ot impose a license fee, royalty, or other charge for exercise of
+rights granted under this License, and you may not initiate litigation
+(including a cross-claim or counterclaim in a lawsuit) allling, offering fd the contributor's "contributor version".
+
+ A contributor's "essential patent claims" are all patent claims
+owned oLicense, of making, using, or selling its contributor version,
+but do not include claims that wimport and otherwise run, modify and
+propagate the contents of its contributor version.
+
+ In the following three paragraphs, a "patent license" is any express
+agreement or commitment, however denominated, not toing on a patent license,
+and the Corresponding Source of the work is not available for anyone
+to copy, free of charge and under the terms of this1) cause the Corresponding Source to be so
+available, or (2) arrangse to downstream recipients. "Knowingly relying" means you have
+actual kble patents in that
+country that you have reason to believe are valid.
+
+ If, pursuant to or in connection with a single transaction or
+arratent license is "discriminatory" if it does not include within
+the scope of its coverage, prohibits the exercise of, or is
+conditioned on the non-exercise of one or more of the rights that are
+specifically grantrty grants, to any of the
+parties who would receive the covered work from you, a discriminatory
+patent license (a) in connection with copies of the c specific products or compilations that
+contain the covered workse orions of this License, they do not
+excuse you from the conditions of this License. If you cannot convey a
+covered work so as to satisfy simultaneously your obligations under this
+License and any other pertinom conveying the Program.
+
+ 13. Use with the GNU Affero General Public License.
+
+ Notwithstanding any other provision of this License, you have
+permission to link or combine any covered work with a work licensening interaction through a network will apply to the
+combination as such.
+
+ 14. Revised Versions of this License.
+
+ The Free Software Foundation may pubns will
+be similar in spirit to the present version, but m License "or any later version" ap the
+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+ If the Program specifies that a proxy can decide which future
+versis a result of your choosing to follow a
+later version.
+
+ 15. Disclaimer of Warranty.
+
+ THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING TOGRAM
+IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+ 16. Limitation of Liability.
+
+ IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN A7. ute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a Your New Programs
diff --git a/Main.hs b/Main.hs
new file mode 100644
--- /dev/null
+++ b/Main.hs
@@ -0,0 +1,65 @@
+{-# LANGUAGE
+ GADTs
+ #-}
+
+-----------------------------------------------------------------------------
+-- |
+-- Module : Main
+-- Author : Matthew Mirman ( mmirman@andrew.cmu.edu )
+-- Stability : experimental
+-- Portability : portable
+-- Description : An example module for Control.Monad.Imperative
+--
+-- License : GNUv3
+--
+-- Copyright (C) 2012 Matthew Mirman
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation, either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program. If not, see
+
+module Main where
+
+import Prelude hiding (break)
+import Control.Monad.Imperative
+
+swap(r1, r2) = function $ do
+{
+ z <- auto undefined;
+ z =: r1;
+ r1 =: r2;
+ r2 =: z;
+};
+
+factorial = function $ do
+{
+ a <- auto 0;
+ n <- auto 1;
+ for ( a =: prim 1 , a <. prim 11 , a +=: prim 1 ) $ do
+ {
+ n *=: a;
+ if' ( a <. prim 7)
+ continue;
+
+ if' ( a >. prim 5)
+ break;
+ };
+
+ swap( (&)n , (&)a);
+
+ returnF n;
+};
+
+
+main = do
+ t <- runImperative factorial
+ putStrLn $ "Some Factorial: "++show t
diff --git a/README b/README
new file mode 100644
--- /dev/null
+++ b/README
@@ -0,0 +1,1 @@
+Just proof that Haskell' can be truly imperative, and even look like C.
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain