Segments for String Mapping

SegmentString.php

<?php

namespace App\Models;

/* SegmentString: Interface between collection of strings with delimiters and the collections
 * Used within eligibility files.
 * Use:
 * $seg = new SegmentString('|', '~', ['a', 'b'])
 * 'a|b~' == (string)$seg
 * ['a', 'b'] == (array)$seg
 */

class SegmentString{
  private $delimiter;
  private $terminator;
  private $collection;
  private $result;

  public function __construct($delimiter, $terminator, $collection = []){
    $this->delimiter = $delimiter;
    $this->terminator = $terminator;
    $this->collection = $collection;
    if($collection == []){
      $this->result = '';
    }
    else{
      $this->delimit()->terminate();
    }
  }

  public function __toString(){
    return $this->result;
  }

  public function __toArray(){
    return $this->collection;
  }

  private function delimit(){
    $this->result = array_reduce($this->collection, function($carry, $subline){
      return $carry.$subline.$this->delimiter;
    });
    return $this;
  }
  
  private function terminate(){
    $this->result = $this->removeTrailing($this->result).$this->terminator;
    return $this;
  }

  //TODO: Revisit
  //Removes any occurances of trailing delimiters such as:
  //a**~ turns into a~
  private function removeTrailing($str){
    if(substr($str, -1) == $this->delimiter) {
      return $this->removeTrailing(substr($str, 0, -1));
    }
    return $str;
  }
}