source: tests/coroutine/cntparens.cfa @ a254fa56

// 
// Cforall Version 1.0.0 Copyright (C) 2017 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
// 
// cntparens.cfa -- match left/right parenthesis
// 
// Author           : Peter A. Buhr
// Created On       : Sat Apr 20 11:04:45 2019
// Last Modified By : Peter A. Buhr
// Last Modified On : Sat Apr 20 11:06:21 2019
// Update Count     : 1
// 

#include <fstream.hfa>
#include <coroutine.hfa>

enum Status { Cont, Match, Error };
coroutine CntParens {
        char ch;                                                                                        // used for communication
        Status status;
        unsigned int cnt;
}; // CntParens

void main( CntParens & cpns ) with( cpns ) {
        for ( ; ch == '('; cnt += 1 ) {                                         // left parenthesis
                suspend();
        }
        for ( ; ch == ')' && cnt > 1; cnt -= 1 ) {                      // right parenthesis
                suspend();
        }
        status = ch == ')' ? Match : Error;
} // main
        
void ?{}( CntParens & cpns ) with( cpns ) { status = Cont; cnt = 0; }

Status next( CntParens & cpns, char c ) with( cpns ) {
        ch = c;
        resume( cpns );
        return status;
}

int main() {
        CntParens cpns;
        char ch;

        for () {                                                                                        // read until end of file
                sin | ch;                                                                               // read one character
          if ( eof( sin ) ) { sout | "Error"; break; }          // eof ?
                Status ret = next( cpns, ch );                                  // push character for formatting
          if ( ret == Match ) { sout | "Match"; break; }
          if ( ret == Error ) { sout | "Error"; break; }
        } // for
} // main

// Local Variables: //
// tab-width: 4 //
// compile-command: "cfa -g -Wall -Wextra cntparens.cfa" //
// End: //