structure conclusion

[msc-thesis1617.git] / mtaskext.bytecode.tex

diff --git a/mtaskext.bytecode.tex b/mtaskext.bytecode.tex
index 111be6f..fd5feee 100644 (file)
--- a/mtaskext.bytecode.tex
+++ b/mtaskext.bytecode.tex
@@ -4,7 +4,7 @@ is added to the \gls{mTask}-system encapsulated in the type \CI{ByteCode}. As
 shown in Listing~\ref{lst:bcview}, the \CI{ByteCode} view is a boxed \gls{RWST}
 that writes bytecode instructions (\CI{BC}, Subsection~\ref{sec:instruction})
 while carrying around a \CI{BCState}. The state is kept between compilations
 shown in Listing~\ref{lst:bcview}, the \CI{ByteCode} view is a boxed \gls{RWST}
 that writes bytecode instructions (\CI{BC}, Subsection~\ref{sec:instruction})
 while carrying around a \CI{BCState}. The state is kept between compilations

-and is unique to a device.  The state contains fresh variable names and a
+and is unique to a device. The state contains fresh variable names and a

 register of \glspl{SDS} that are used.
 
 Types implementing the \gls{mTask} classes must have two free type variables.
 register of \glspl{SDS} that are used.
 
 Types implementing the \gls{mTask} classes must have two free type variables.


@@ -24,19 +24,23 @@ the content. Most notably, the type must be bytecode encodable. A \CI{BCValue}
 must be encodable and decodable without losing type or value information. At
 the moment a simple encoding scheme is used that uses single byte prefixes to
 detect the type of the value. The devices know these prefixes and can apply the
 must be encodable and decodable without losing type or value information. At
 the moment a simple encoding scheme is used that uses single byte prefixes to
 detect the type of the value. The devices know these prefixes and can apply the

-same detection if necessary.
+same detection if necessary. Note that \CI{BCValue} uses existentially
+quantified type variables and therefore it is not possible to derive class
+instances such as \CI{iTasks}. Tailor-made instances for these functions have
+been made.

 
 \begin{lstlisting}[label={lst:bcview},caption={Bytecode view}]
 :: ByteCode a p = BC (RWS () [BC] BCState ())
 :: BCValue = E.e: BCValue e & mTaskType, TC e
 :: BCShare =
 
 \begin{lstlisting}[label={lst:bcview},caption={Bytecode view}]
 :: ByteCode a p = BC (RWS () [BC] BCState ())
 :: BCValue = E.e: BCValue e & mTaskType, TC e
 :: BCShare =

-       { sdsi :: Int
-       , sdsval :: BCValue
+       { sdsi    :: Int
+       , sdsval  :: BCValue
+       , sdsname :: String

        }
 :: BCState = 
        { freshl :: Int
        , freshs :: Int
        }
 :: BCState = 
        { freshl :: Int
        , freshs :: Int

-       , sdss :: [BCShare]
+       , sdss   :: [BCShare]

        }
 
 class toByteCode a :: a -> String
        }
 
 class toByteCode a :: a -> String


@@ -170,12 +174,12 @@ instance noOp ByteCode where
 The semantics for the \gls{mTask}-\glspl{Task} bytecode view are different from
 the semantics of the \gls{C} view. \glspl{Task} in the \gls{C} view can start
 new \glspl{Task} or even start themselves to continue, while in the bytecode
 The semantics for the \gls{mTask}-\glspl{Task} bytecode view are different from
 the semantics of the \gls{C} view. \glspl{Task} in the \gls{C} view can start
 new \glspl{Task} or even start themselves to continue, while in the bytecode

-view, \glspl{Task} run indefinitely, one-shot or on interrupt. To allow interval
-and interrupt \glspl{Task} to terminate, a return instruction is added. This
-class was not available in the original system and is thus added. It just
-writes a single instruction so that the interpreter knows to stop execution.
-Listing~\ref{lst:return} shows the classes and implementation for the return
-expression.
+view, \glspl{Task} run indefinitely, one-shot or on interrupt. To allow
+interval and interrupt \glspl{Task} to terminate, a return instruction is
+added. This class was not available in the original system and is thus added.
+It just writes a single instruction so that the interpreter knows to stop
+execution.  Listing~\ref{lst:return} shows the classes and implementation for
+the return expression.

 
 \begin{lstlisting}[label={lst:return},%
        caption={Bytecode view for the return instruction}]
 
 \begin{lstlisting}[label={lst:return},%
        caption={Bytecode view for the return instruction}]


@@ -188,11 +192,13 @@ instance retrn ByteCode where
 
 \subsection{Shared Data Sources \& Assignment}
 Fresh \gls{SDS} are generated using the state and constructing one involves
 
 \subsection{Shared Data Sources \& Assignment}
 Fresh \gls{SDS} are generated using the state and constructing one involves

-multiple steps.  First, a fresh identifier is grabbed from the state.  Then a
+multiple steps. First, a fresh identifier is grabbed from the state.  Then a

 \CI{BCShare} record is created with that identifier. A \CI{BCSdsFetch}
 instruction is written and the body is generated to finally add the \gls{SDS}
 to the actual state with the value obtained from the function. The exact
 \CI{BCShare} record is created with that identifier. A \CI{BCSdsFetch}
 instruction is written and the body is generated to finally add the \gls{SDS}
 to the actual state with the value obtained from the function. The exact

-implementation is shown in Listing~\ref{lst:shareview}.
+implementation is shown in Listing~\ref{lst:shareview}. The implementation for
+the \CI{namedsds} class is exactly the same other than that it stores the given
+name in the \CI{BCShare} structure as well.

 
 \begin{lstlisting}[label={lst:shareview},%
        caption={Bytecode view for \texttt{arith}}]
 
 \begin{lstlisting}[label={lst:shareview},%
        caption={Bytecode view for \texttt{arith}}]


@@ -200,7 +206,7 @@ freshshare = get >>= \st=:{freshs}->put {st & freshs=freshs+1} >>| pure freshs
 
 instance sds ByteCode where
        sds f = {main = BC (freshshare
 
 instance sds ByteCode where
        sds f = {main = BC (freshshare

-                       >>= \sdsi->pure {BCShare|sdsi=sdsi,sdsval=BCValue 0}
+                       >>= \sdsi->pure {BCShare|sdsname="",sdsi=sdsi,sdsval=BCValue 0}

                        >>= \sds->pure (f (tell` [BCSdsFetch sds]))
                        >>= \(v In bdy)->modify (addSDS sds v)
                        >>| unBC (unMain bdy))
                        >>= \sds->pure (f (tell` [BCSdsFetch sds]))
                        >>= \(v In bdy)->modify (addSDS sds v)
                        >>| unBC (unMain bdy))


@@ -211,16 +217,16 @@ instance sdspub ByteCode where
 addSDS sds v s = {s & sdss=[{sds & sdsval=BCValue v}:s.sdss]}
 \end{lstlisting}
 
 addSDS sds v s = {s & sdss=[{sds & sdsval=BCValue v}:s.sdss]}
 \end{lstlisting}
 

-All assignable types compile to a \gls{RWST} which writes the specific fetch
-instruction(s). For example, using an \gls{SDS} always results in an
-expression of the form \CI{sds \x=4 In ...}. The actual \CI{x} is the
+All assignable types compile to an \gls{RWST} which writes the specific fetch
+instruction(s). For example, using an \gls{SDS} always results in % chktex 36
+an expression of the form \CI{sds \x=4 In ...}. The actual \CI{x} is the

 \gls{RWST} that always writes one \CI{BCSdsFetch} instruction with the
 \gls{RWST} that always writes one \CI{BCSdsFetch} instruction with the

-correctly embedded \gls{SDS}.  Assigning to an analog pin will result in the
+correctly embedded \gls{SDS}. Assigning to an analog pin will result in the

 \gls{RWST} containing the \CI{BCAnalogRead} instruction. When the operation on
 the assignable is not a read operation from but an assign operation, the
 \gls{RWST} containing the \CI{BCAnalogRead} instruction. When the operation on
 the assignable is not a read operation from but an assign operation, the

-instruction(s) will be rewritten accordingly. This results in a \CI{BCSdsStore}
-or \CI{BCAnalogWrite} instruction respectively. The implementation for this is
-given in Listing~\ref{lst:assignmentview}.
+instruction(s) will be rewritten accordingly. This results in a %chktex 36
+\CI{BCSdsStore} or \CI{BCAnalogWrite} instruction respectively. The
+implementation for this is given in Listing~\ref{lst:assignmentview}.

 
 \begin{lstlisting}[label={lst:assignmentview},%
        caption={Bytecode view implementation for assignment.}]
 
 \begin{lstlisting}[label={lst:assignmentview},%
        caption={Bytecode view implementation for assignment.}]