source: doc/papers/concurrency/examples/Format1.c @ 2210cfc

#include <stdio.h>

typedef struct {
        int restart, g, b;
        char ch;
} Fmt;

void format( Fmt * f ) {
        static void * states[] = {&&s0, &&s1};
        goto *states[f->restart];
  s0: f->restart = 1;
        for ( ;; ) {
                for ( f->g = 0; f->g < 5; f->g += 1 ) {                 // groups
                        for ( f->b = 0; f->b < 4; f->b += 1 ) {         // blocks
                                return;
                          s1: if ( f->ch == '\0' ) goto fini;           // EOF ?
                                while ( f->ch == '\n' ) return;                 // ignore
//                              printf( "%c", f->ch );                                  // print character
                        }
//                      printf( " " );                                                          // block separator
                }
//              printf( "\n" );                                                                 // group separator
        }
  fini:;
//      if ( f->g != 0 || f->b != 0 ) printf( "\n" );
}

int main() {
        Fmt fmt = { 0 };
        format( &fmt );                                                                         // prime
        fmt.ch = 'a';
        for ( long int i = 0; i < 1000000000; i += 1 ) {
//              scanf( "%c", &fmt.ch );                                                 // direct read into communication variable
//        if ( feof( stdin ) ) break;
                format( &fmt );
        }
        fmt.ch = '\0';                                                                          // sentential (EOF)
        format( &fmt );
}

// Local Variables: //
// tab-width: 4 //
// compile-command: "gcc-8 Format1.c" //
// End: //