writeln("Hello, world!");

// create a parallel task per processor core
coforall tid in 0..<here.maxTaskPar do
  writeln("Hello from task ", tid);

// print these 1,000 messages in parallel using all cores
forall i in 1..1000 do
  writeln("Hello from iteration ", i);

// print a message per compute node
coforall loc in Locales do
  on loc do
    writeln("Hello from locale ", loc.id);

// print a message per core per compute node
coforall loc in Locales do
  on loc do
    coforall tid in 0..<here.maxTaskPar do
      writeln("Hello from task ", tid, " on locale ", loc.id);

// print 1,000 messages in parallel using all nodes and cores
use BlockDist;
const Inds = blockDist.createDomain(1..1000);
forall i in Inds do
  writeln("Hello from iteration ", i, " running on locale ", here.id);

use IO;

// read in a file containing 'city name;temperature' lines (1BRC-style)
const stats = [line in stdin.lines()] new cityTemperature(line);
writeln(stats);

record cityTemperature {
  const city: string;  // city name
  const temp: real;    // temperature

  proc init(str: string) {
    const words = str.split(";");
    this.city = words[0];
    this.temp = words[1]: real;
  }
}

// set different values at runtime with command line arguments
// e.g. --n=2048 --numSteps=256 --alpha=0.8
config const n = 1000,
             numSteps = 100,
             alpha = 1.0;

const fullDomain = {1..n},
      interior   = {2..n-1};

var u: [fullDomain] real = 1.0; 
u[n/4..3*n/4] = 2.0;  // make the middle a bit hotter

var un = u;

for 1..numSteps {
  forall i in interior do  // shared-memory parallelism
    u[i] = un[i] + alpha * (un[i-1] - 2*un[i] + un[i+1]);  
  un <=> u;  // swap the two arrays
}

writeln(un);

use Random, Math;

const nGpus = here.gpus.size,
      n     = Locales.size*nGpus;

var A: [1..n, 1..n] real;

fillRandom(A);

// use all nodes
coforall (loc, localRowStart) in zip(Locales, 1.. by nGpus) do on loc { 
  // and all GPUs within each
  coforall (gpu, row) in zip(here.gpus, localRowStart..) do on gpu {    
    var B: [1..n] real = A[row, ..];    // copy a row from device to host
    B = asin(B);                        // compute (kernel launch)
    A[row, ..] = B;                     // copy the row back
  }
}

writeln(A);