Print WordPress Taxonomy Terms as list

print_terms.php

<?php
  /**
   * Print WordPress Taxonomy Terms as list
   * @param  [type] $terms_array [description]
   * @param  [type] $first_item  [description]
   * @return [type]              [description]
   */
  function print_terms($terms_array, &$first_item) {
    if(!$terms_array || count($terms_array) < 1) return;
    foreach($terms_array as $term) {
      if(!$first_item) { echo ", "; }
      else { $first_item = false; }
      echo '<a href="'.get_term_link($term->term_id).'">' . $term->name . '</a>';
    }
  }

  // Call
  $first_item = true;
  print_terms( get_the_terms(get_the_ID(), 'post_tag' ), $first_item );
?>