source: doc/uC++toCFA/uC++toCFA.tex @ a3af522

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%%
%% Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
%%
%% The contents of this file are covered under the licence agreement in the
%% file "LICENCE" distributed with Cforall.
%%
%% user.tex --
%%
%% Author           : Peter A. Buhr
%% Created On       : Wed Apr  6 14:53:29 2016
%% Last Modified By : Peter A. Buhr
%% Last Modified On : Fri Nov  8 08:22:25 2024
%% Update Count     : 6107
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\usepackage{fullpage,times,comment}
\usepackage{epic,eepic}
\usepackage{upquote}                                                                    % switch curled `'" to straight
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\input{common}                                                                                  % common CFA document macros
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\usepackage{breakurl}

\renewcommand\footnoterule{\kern -3pt\rule{0.3\linewidth}{0.15pt}\kern 2pt}
\newcommand{\uC}{$\mu$\CC}

% Default underscore is too low and wide. Cannot use lstlisting "literate" as replacing underscore
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\setlength{\gcolumnposn}{3in}
\CFAStyle                                                                                               % use default CFA format-style
\lstset{language=CFA}                                                                   % CFA default lnaguage
\lstnewenvironment{C++}[1][]                            % use C++ style
{\lstset{language=C++,escapechar=\$,mathescape=false,moredelim=**[is][\protect\color{red}]{@}{@},#1}}{}
\lstnewenvironment{uC++}[1][]
{\lstset{language=uC++,escapechar=\$,mathescape=false,moredelim=**[is][\protect\color{red}]{@}{@},#1}}{}

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\title{\vspace*{-0.5in}
\uC to \CFA Cheat Sheet}
%\author{Peter A. Buhr}
\date{}

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\begin{document}
\pagestyle{headings}
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\renewcommand{\sectionmark}[1]{\markboth{\thesection\quad #1}{\thesection\quad #1}}
\renewcommand{\subsectionmark}[1]{\markboth{\thesubsection\quad #1}{\thesubsection\quad #1}}

%\linenumbers                                            % comment out to turn off line numbering

\maketitle
\vspace*{-0.55in}

\section{Introduction}

\CFA is NOT an object-oriented programming-language.
\CFA uses parametric polymorphism and allows overloading of variables and routines:
\begin{cfa}
int i;  char i;  double i;      $\C[2in]{// overload name i}$
int i();  double i();  char i();
i += 1;                                         $\C{// int i}$
i += 1.0;                                       $\C{// double i}$
i += 'a';                                       $\C{// char i}$
int j = i();                            $\C{// int i()}$
double j = i();                         $\C{// double i();}$
char j = i();                           $\C{// char i()}\CRT$
\end{cfa}
\CFA has rebindable references.
\begin{cquote}
\begin{tabular}{@{}l|l@{}}
\multicolumn{2}{@{}l}{\lstinline{       int x = 1, y = 2, * p1x = &x, * p1y = &y, ** p2i = &p1x,}} \\
\multicolumn{2}{@{}l}{\lstinline{\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ & r1x = x, & r1y = y, && r2i = r1x;}} \\
\begin{uC++}
**p2i = 3;
p2i = &p1y;
**p2i = 3;
p1x = p1y;
**p2i = 4;
p1x = @nullptr@;
\end{uC++}
&
\begin{cfa}
r2i = 3; $\C[1.0in]{// change x}$
&r2i = &r1y; $\C{// change p2i / r2i}$
r2i = 3; $\C{// change y}$
&r1x = &r1y; $\C{// change p1x / r1x}$
r2i = 4; $\C{// change y}$
&r1x = @0p@; $\C{// reset}\CRT$
\end{cfa}
\end{tabular}
\end{cquote}
Non-rebindable reference (\CC reference) is a @const@ reference (@const@ pointer).
\begin{cfa}
int & @const@ cr = x; // must initialize, no null pointer
int & @const@ & @const@ crcr = cr; // generalize
\end{cfa}
Aggregate qualification is reduced or eliminated by opening scopes using the @with@ clause.
\begin{cfa}
struct S { int i; int j; double m; };  // field i has same type in structures S and T
struct T { int i; int k; int m; };
void foo( S s, T t ) @with( s, t )@ {   // open structure scope s and t in parallel
        j + k;                          $\C[1.6in]{// unambiguous, s.j + t.k}$
        m = 5.0;                        $\C{// unambiguous, s.m = 5.0}$
        m = 1;                          $\C{// unambiguous, t.m = 1}$
        int a = m;                      $\C{// unambiguous, a = t.m}$
        double b = m;           $\C{// unambiguous, b = s.m}$
        int c = s.i + t.i;      $\C{// unambiguous with qualification}$
        (double)m;                      $\C{// unambiguous with cast s.m}\CRT$
}
\end{cfa}
\noindent
In subsequent code examples, the left example is \uC and the right example is \CFA.


\section{Stream I/O}

\CFA output streams automatically separate values and insert a newline at the end of the print.
\begin{cquote}
\begin{tabular}{@{}l|l@{}}
\begin{uC++}
#include <@iostream@>
using namespace std;
int i;   double d;   char c;
cin >> i >> d >> c;
cout << i << ' ' << d << ' ' << c | endl;
\end{uC++}
&
\begin{cfa}
#include <@fstream.hfa@>

int i;   double d;   char c;
sin | i | d | c;
sout | i | d | c
\end{cfa}
\end{tabular}
\end{cquote}


\section{Looping}

\begin{cquote}
\begin{tabular}{@{}l|l@{}}
\begin{uC++}
for ( @;;@ ) { ... }  /  while ( @true@ ) { ... }
for ( int i = 0; i < @10@; i += 1 ) { ... }
for ( int i = @5@; i < @15@; i += @2@ ) { ... }
for ( int i = -1; i <@=@ 10; i += 3 ) { ... }
for ( int i = 10; i > 0; i @-@= 1 ) { ... }
\end{uC++}
&
\begin{cfa}
for () { ... }  /  while () { ... }
for ( @10@ ) { ... }  /  for ( i; @10@ ) { ... }
for ( i; @5@ ~ @15@ ~ @2@ ) { ... }
for ( i; -1 ~@=@ 10 ~ 3 ) { ... }
for ( i; 0 @-@~ 10 ) { ... }
\end{cfa}
\\
\hline
\begin{uC++}
int i = 0
for ( i = 0; i < 10; i += 1 ) { ... }
@if ( i == 10 )@ { ... }
\end{uC++}
&
\begin{cfa}

for ( i; 10 ) { ... }
@else@ { ... } // i == 10
\end{cfa}
\\
\hline
\begin{uC++}
@L1:@ for ( ;; ) {
        @L2:@ for ( ;; ) {
                ... if ( ... ) @break L1@; ...
                ... if ( ... ) @break L2@; ...
        }
}
\end{uC++}
&
\begin{cfa}
@L1:@ for () {
        @L2:@ for () {
                ... if ( ... ) @break L1@; ...
                ... if ( ... ) @break L2@; ...
        }
}
\end{cfa}
\end{tabular}
\end{cquote}


\section{Exception}

Currently, \CFA uses macros @ExceptionDecl@ and @ExceptionInst@ to declare and instantiate an exception.
\begin{cquote}
\begin{tabular}{@{}l|ll@{}}
\begin{uC++}

@_Exception@ E {        // local or global scope
        ... // exception fields
};
try {
        ...
        if ( ... ) @_Resume@ E( /* initialization */ );
        if ( ... ) @_Throw@ E( /* initialization */ );
                ...
} @_CatchResume@( E & ) { ... // reference
} catch( E & ) { ...
} catch( ... ) { ... // catch any
} _Finally { ...
}
\end{uC++}
&
\begin{cfa}
#include <Exception.hfa>
@ExceptionDecl@( E,             // must be global scope
        ... // exception fields
);
try {
        ...
        if ( ... ) @throwResume@ @ExceptionInst@( E, /* intialization */ );
        if ( ... ) @throw@ @ExceptionInst@( E, /* intialization */ );
        ...
} @catchResume@( E * ) { ... // pointer
} catch( E * ) { ...
} catch( exception_t * ) { ... // catch any
} finally { ...
}
\end{cfa}
\end{tabular}
\end{cquote}


\section{Non-local Exception}

\begin{cquote}
\begin{tabular}{@{}l|ll@{}}
\begin{uC++}


void main() {
        try {
                _Enable {
                        ... suspend(); ...
                }
        } @_CatchResume@( E & ) { // reference
                ...
        } catch( E & ) {
                ...
        }
}
\end{uC++}
&
\begin{cfa}
#define resumePoll( coroutine ) resume( coroutine ); checked_poll()
#define suspendPoll suspend; checked_poll()
void main() {
        try {
                enable_ehm();
                ... suspendPoll ...
                disable_ehm();
        } @catchResume@( E * ) { // pointer
                ...
        } catch( E & ) {
                ...
        }
}
\end{cfa}
\end{tabular}
\end{cquote}


\section{\texorpdfstring{Structures (object-oriented \protect\vs routine style)}{Structures (object-oriented vs. routine style)}}

\begin{cquote}
\begin{tabular}{@{}l|l@{}}
\begin{uC++}
struct S {
        int i = 0;  // cheat, implicit default constructor
        int setter( int j ) { int t = i; i = j; return t; }
        int getter() { return i; }
};
S s;
@s.@setter( 3 );  // object calls
int k = @s.@getter();
\end{uC++}
&
\begin{cfa}
struct S {  int i;  };
void ?{}( S & s ) { s.i = 0; } // explicit default constructor
int setter( @S & s,@ int j ) @with( s )@ { int t = i; i = j; return t; }
int getter( @S & s@ ) @with( s )@ { return i; }

S s;
setter( @s,@ 3 );  // normal calls
int k = getter( @s@ );
\end{cfa}
\end{tabular}
\end{cquote}


\section{Constructor / Destructor}

\begin{cquote}
\begin{tabular}{@{}l|l@{}}
\begin{uC++}

struct S {
        int i, j;
        @S@( int i, int j ) { S::i = i; S::j = j; }
        @~S@() {}
};
S s = { 1, 2 }, s2{ 1, 2 };
S * s3 = new S{ 1, 2 };
S & s4 = *new S{ 1, 2 };
\end{uC++}
&
\begin{cfa}
#include <stdlib.hfa> // malloc
struct S {
        int i, j;
};
void @?{}( S & s@, int i, int j ) { s.[i, j] = [i, j]; }
void @^?{}( S & s@ ) {}
S s = { 1, 2 }, s2{ 1, 2 };
S * s3 = &(*malloc()){ 1, 2 };
S & s4 = (*malloc()){ 1, 2 }; // fails
\end{cfa}
\end{tabular}
\end{cquote}


\section{String}

\begin{cquote}
\begin{tabular}{@{}l|l@{}}
\multicolumn{2}{@{}l@{}}{\lstinline{string s1, s2;}} \\
\begin{uC++}
s1 = "abcdefg";
s2 = s1;
s1 += s2;
s1 == s2; s1 != s2;
s1 < s2; s1 <= s2; s1 > s2; s1 >= s2;
s1.length();
s1[3];
s1.substr( 2 ); s1.substr( 2, 3 );
s1.replace( 2, 5, s2 );
s1.find( s2 ); s1.rfind( s2 );
s1.find_first_of( s2 ); s1.find_last_of( s2 );
s1.find_first_not_of( s2 ); s1.find_last_not_of( s2 );
getline( cin, s1 );
cout << s1 << endl;
\end{uC++}
&
\begin{cfa}
s1 = "abcdefg";
s2 = s1;
s1 += s2;
s1 == s2; s1 != s2;
s1 < s2; s1 <= s2; s1 > s2; s1 >= s2;
size( s1 );
s1[3];
s1( 2 ); s1( 2, 3 );
// replace( s1, 2, 5, s2 );
// find( s1, s2 ), rfind( s1, s2 );
// find_first_of( s2 ); find_last_of( s2 );
// find_first_not_of( s1, s2 ); find_last_not_of( s1, s2 );
sin | getline( s1 );
sout | s1;
\end{cfa}
\end{tabular}
\end{cquote}


\section{\texorpdfstring{\lstinline{uArray}}{uArray}}

\begin{cquote}
\begin{tabular}{@{}l|l@{}}
\begin{uC++}
#include <iostream>
using namespace std;
struct S {
        int i;
        S( int i ) { S::i = i; cout << "ctor " << S::i << endl; }
        ~S() { S::i = i; cout << "dtor " << S::i << endl; }
};
int main() {
        enum { N = 5 };
        @uArray( S, s, N );@   // no constructor calls
        for ( int i = 0; i < N; i += 1 ) @s[i]( i )@; // constructor calls
        for ( int i = 0; i < N; i += 1 ) cout << s[i]@->@i << endl;
}
\end{uC++}
&
\begin{cfa}
#include <fstream.hfa>
#include <array.hfa>
struct S {
        int i;
};
void ?{}( S & s, int i ) { s.i = i; sout | "ctor" | s.i; }
void ^?{}( S & s ) { sout | "dtor" | s.i; }
int main() {
        enum { N = 5 };
        @array( S, N ) s = { delay_init };@ // no constructor calls
        for ( i; N ) @s[i]{ i }@; // constructor calls
        for ( i; N ) sout | s[i]@.@i;
}
\end{cfa}
\end{tabular}
\end{cquote}


\section{Coroutines}

\begin{cquote}
\begin{tabular}{@{}l|ll@{}}
\begin{uC++}

@_Coroutine@ C {
        // private coroutine fields
        void main() {
                ... @suspend();@ ...
                ... @_Resume E( ... ) _At partner;@
                ... @uThisCoroutine();@ ...

        }
  public:
        void mem( ... ) {
                ... @resume();@ ...
        }
};
\end{uC++}
&
\begin{cfa}
#include <$coroutine$.hfa>
@coroutine@ C {
        // private coroutine fields

};
void main( C & c ) {
        ... @suspend;@ ... // keyword not routine
        ... @resumeAt( partner, ExceptionInst( E, ... ) );@
        ... @active_coroutine();@ ...
}
void mem( C & c, ... ) {
        ... @resume( c );@ ...
}
\end{cfa}
\\
\multicolumn{2}{@{}l@{}}{\lstinline{C c;}}
\end{tabular}
\end{cquote}


\section{\lstinline{COBEGIN}/\lstinline{COFOR}}

\begin{cquote}
\begin{tabular}{@{}l|ll@{}}
\begin{uC++}

#include <uCobegin.h>
int main() {
        @COBEGIN@
                BEGIN osacquire( cout ) << "A" << endl; END
                BEGIN osacquire( cout ) << "B" << endl; END
                BEGIN osacquire( cout ) << "C" << endl; END
                BEGIN osacquire( cout ) << "D" << endl; END
                BEGIN osacquire( cout ) << "E" << endl; END
        @COEND@
        @COFOR@( i, 1, 10,
                osacquire( cout ) << i << endl;
        )
}
\end{uC++}
&
\begin{cfa}
#include <mutex_stmt.hfa>
#include <$cofor$.hfa>
int main() {
        {
                @corun@ { mutex( sout ) sout | "A"; }
                corun { mutex( sout ) sout | "B"; }
                corun { mutex( sout ) sout | "C"; }
                corun { mutex( sout ) sout | "D"; }
                corun { mutex( sout ) sout | "E"; }
        }
        @cofor@( i; 10 ) {
                mutex( sout ) sout | i;
    }
}
\end{cfa}
\end{tabular}
\end{cquote}


\section{Actor}

\begin{cquote}
\begin{tabular}{@{}l|ll@{}}
\begin{uC++}
#include <iostream>
using namespace std;
#include <uActor.h>

struct StrMsg : @public uActor::Message@ {
        const char * val; // string message


        StrMsg( const char * val ) :
                @Message( uActor::Delete )@, // delete after use
                val( val ) {}
};
_Actor Hello { ${\color{red}\LstCommentStyle{// : public uActor}}$
        Allocation receive( Message & msg ) {
                Case( StrMsg, msg ) { // discriminate
                        osacquire( cout ) << msg_d->val << endl;
                };
                return Delete;  // delete after use
        }
};
int main() {
        @uActor::start();@ // start actor system
        *new Hello() | *new StrMsg( "hello" );
        *new Hello() | *new StrMsg( "bonjour" );
        @uActor::stop();@  // wait for all actors to terminate
}
\end{uC++}
&
\begin{cfa}
#include <fstream.hfa>
#include <mutex_stmt.hfa>
#include <actor.hfa>

struct StrMsg {
        @inline message;@ // derived message
        const char * val; // string message
};
void ?{}( StrMsg & msg, char * str ) {
        msg.val = str;
        @set_allocation( msg, Delete );@ // delete after use
}
struct Hello {
        @inline actor;@ // derived actor
};
allocation receive( Hello & receiver, StrMsg & msg ) {
        mutex( sout ) sout | msg.val;
        return Delete;  // delete after use
}

int main() {
        @start_actor_system();@  // start actor system
        *(Hello *)new() | *(StrMsg *)new( "hello" );
        *(Hello *)new() | *(StrMsg *)new( "bonjour" );
        @stop_actor_system();@  // wait for all actors to terminate
}
\end{cfa}
\end{tabular}
\end{cquote}


\section{Threads}

\begin{cquote}
\begin{tabular}{@{}l|ll@{}}
\begin{uC++}

@_Task@ T {
        // private task fields
        void main() {
                ... _Resume E( ... ) _At partner;
                ... uThisTask(); ...
        }
  public:
};
\end{uC++}
&
\begin{cfa}
#include <$thread$.hfa>
@thread@ T {
        // private task fields

};
void main( @T & t@ ) {
        ... resumeAt( partner, ExceptionInst( E, ... ) );
        ... active_thread(); ...
}
\end{cfa}
\\
\multicolumn{2}{@{}l@{}}{\lstinline{T t; // start thread in main routine}}
\end{tabular}
\end{cquote}


\section{Locks}

\begin{cquote}
\begin{tabular}{@{}l|ll@{}}
\begin{uC++}

uOwnerLock m;
uCondLock s;
m.acquire();
if ( ! s.empty() ) s.wait( m );
else {
        m.release();
}
@osacquire( cout )@ << i << endl;
\end{uC++}
&
\begin{cfa}
#include <locks.hfa>
owner_lock m;
condition_variable( owner_lock ) s;  // generic type on mutex lock
lock( m );
if ( ! empty( s ) ) wait( s, m );
else {
        unlock( m );
}
@mutex( sout )@ sout | i;  // thread safe I/O
\end{cfa}
\end{tabular}
\end{cquote}


\section{Monitors}

Internal Scheduling
\begin{cquote}
\begin{tabular}{@{}l|ll@{}}
\begin{uC++}

@_Monitor@ BoundedBufferI {
        @uCondition@ full, empty;
        int front = 0, back = 0, count = 0;
        int elements[20];
  public:



        @_Nomutex@ int query() const { return count; }

        void insert( int elem ) {
                if ( count == 20 ) @empty.wait();@
                elements[back] = elem;
                back = ( back + 1 ) % 20;
                count += 1;
                @full.signal();@
        }
        int remove() {
                if ( count == 0 ) @full.wait();@
                int elem = elements[front];
                front = ( front + 1 ) % 20;
                count -= 1;
                @empty.signal();@
                return elem;
        }
};
\end{uC++}
&
\begin{cfa}
#include <$monitor$.hfa>
@monitor@ BoundedBufferI {
        @condition@ full, empty;
        int front, back, count;
        int elements[20];
};
void ?{}( BoundedBufferI & buf ) with( buf ) {
        front = back = count = 0;
}
int query( BoundedBufferI & buf ) { return buf.count; }
int remove( BoundedBufferI & @mutex@ buf ); // forward
void insert( BoundedBufferI & @mutex@ buf, int elem ) with( buf ) {
        if ( count == 20 ) @wait( empty );@
        elements[back] = elem;
        back = ( back + 1 ) % 20;
        count += 1
        @signal( full );@
}
int remove( BoundedBufferI & @mutex@ buf ) with( buf ) {
        if ( count == 0 ) @wait( full );@
        int elem = elements[front];
        front = ( front + 1 ) % 20;
        count -= 1;
        @signal( empty );@
        return elem;
}

\end{cfa}
\end{tabular}
\end{cquote}
\enlargethispage{1000pt}
External Scheduling
\begin{cquote}
\begin{tabular}{@{}l|ll@{}}
\begin{uC++}

_Monitor BoundedBuffer {
        int front = 0, back = 0, count = 0;
        int elements[20];
  public:
        _Nomutex int query() const { return count; }
        void insert( int elem );
        int remove();
};

void BoundedBuffer::insert( int elem ) {
        if ( count == 20 ) @_Accept( remove );@
        elements[back] = elem;
        back = ( back + 1 ) % 20;
        count += 1;
}
int BoundedBuffer::remove() {
        if ( count == 0 ) @_Accept( insert );@
        int elem = elements[front];
        front = ( front + 1 ) % 20;
        count -= 1;
        return elem;
}
\end{uC++}
&
\begin{cfa}
#include <$monitor$.hfa>
monitor BoundedBuffer {
        int front, back, count;
        int elements[20];
};
void ?{}( BoundedBuffer & buf ) with( buf ) {
        front = back = count = 0;
}
int query( BoundedBuffer & buf ) { return buf.count; }
int remove( BoundedBuffer & @mutex@ buf ); // forward
void insert( BoundedBuffer & @mutex@ buf, int elem ) with( buf ) {
        if ( count == 20 ) @waitfor( remove : buf );@
        elements[back] = elem;
        back = ( back + 1 ) % 20;
        count += 1;
}
int remove( BoundedBuffer & @mutex@ buf ) with( buf ) {
        if ( count == 0 ) @waitfor( insert : buf );@
        int elem = elements[front];
        front = ( front + 1 ) % 20;
        count -= 1;
        return elem;
}
\end{cfa}
\end{tabular}
\end{cquote}


\input{uC++toCFA.ind}

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