this is an implementation for python's starmap method in Chapel

example9Starmap.chpl

use RangeChunk;
use Time;


// serial

iter starmap(array, function) {
  var iterable = array;         // I know that I don't need to copy "array" to new variable "iterable"
  for i in iterable {
    yield function((...i));
  }
}

// leader

iter starmap(param tag: iterKind, array, function)
    where tag == iterKind.leader {
    var numTasks = here.maxTaskPar;
    var Range = array.domain.low..array.domain.high;
    coforall tid in 0..#numTasks {
        var nowRange = chunk(Range, numTasks, tid);
        yield (nowRange, );
    }   
}


// follower

iter starmap(param tag: iterKind, array, function, followThis)
    where tag == iterKind.follower && followThis.size == 1 {
    var nowRange = followThis(1);
    for i in nowRange {
        yield function((...array[i]));
    }
}


var used_1 = [(1,2), (3,2), (2,5), (10,2), (9,1)];
proc funcUsed_1(a: int, b: int) : int {
    return a**b;
}

writeln("serial");
for i in starmap(used_1, funcUsed_1) {
    writeln(i);
}

writeln("parallel")
forall i in starmap(used_1, funcUsed_1) {
    writeln(i);
}