source: doc/theses/mike_brooks_MMath/programs/hello-array.cfa@ d02d223

#include <fstream.hfa>
#include <stdlib.hfa>
#include <array.hfa> // learned has to come afer stdlib, which uses the word tag

// Usage:
// ./a.out 5
// example does an unchecked reference to argv[1]


forall( [@N@] )                                                         $\C{// array dimension}$
array( bool, @N@) & f( array( float, @N@ ) & x, array( float, @N@ ) & y ) {
        array( bool, @N@ ) & ret = *@alloc@();  $\C{// sizeof ret  used by alloc}$
        for ( i; @N@ ) {
                ret[i] = 0.005 > 2 * (abs( x[i] - y[i] )) / (abs( x[i]) + abs(y[i] ));
        }
        return ret;
}










// TODO: standardize argv

int main( int argc, char * argv[] ) {
        const int @n@ = ato( argv[1] );                 $\C{// deduce conversion type}$
        array( float, @n@ ) x, y;                               $\C{// VLAs}$
        for ( i; n ) {                                                  $\C{// initialize arrays}$
                x[i] = 3.14 / (i + 1);
                y[i] = x[i] + 0.005 ;
        }
        array( bool, @n@ ) & result = @f( x, y )@; $\C{// call}$
        sout | "result: " | nonl;                               $\C{// print result}$
        for ( i; n )
                sout | result[i] | nonl;
        sout | nl;
        free( &result );                                                $\C{// free result storage}$
}
/*
$\$$ ./a.out 5
result: true true true false false
$\$$ ./a.out 7
result: true true true false false false false
*/

void fred() {
        array( float, @10@ ) x;
        array( float, @20@ ) y;
        f( x, x );
        f( y, y );
//      f( x, y );
}

#ifdef SHOWERR1
forall( [M], [N] )
void bad( array(float, M) &x, array(float, N) &y ) {
        f( x, x );              $\C[1.5in]{// ok}$
        f( y, y );              $\C{// ok}$
        f( x, y );              $\C{// error}\CRT$
}
#endif



forall( [M], [N] )
void bad_fixed( array( float, M ) & x, array( float, N ) & y ) {
        if ( M == N )
                f( x, @(array( float, M ) &)@y ); $\C{// cast y to matching type}$
}

// Local Variables: //
// compile-command: "sed -f sedcmd hello-array.cfa > ../build/tmp.cfa; cfa ../build/tmp.cfa -Wall -Wextra" //
// End: //