You almost can do this in PHP, almost.

promises-promises.php

<?php

// generators are weaker than monads and this is therefore not possible
// CPS transformation to state machines sucks balls

$usersWhoCommentedOnTheirPosts = run($seqMonad, function () {
  $user = (yield allUsers());
  $post = (yield $user->posts);
  $comm = (yield $post->comments);
  if ($comm->author === $comm->author)
  yield [$user, $post, $comm];
});

the-same-thing.scala

// same thing in Scala look pretty much the same

val usersWhoCommentedOnTheirVisiblePosts = for {
  user <- allUsers
  post <- user.posts
  comm <- post.comments
  if comm.author == comm.author
} yield (user, post, comm)

I think the Scala example is wrong, it should probably be:

val usersWhoCommentedOnTheirVisiblePosts = for {
  user <- allUsers
  post <- user.posts
  comm <- post.comments
  if comm.author == comm.author // dolble "="
  // move yielf out of these brackets
} yield (user, post, comm);
// There was an extra bracket on line 9.

Real men don't test their code. Really real men don't even compile their code.