Blog - AVOID “REGEX TOO COMPLICATED” ISSUES PROCESSING LARGE FILES

gistfile1.cls

public with sharing class Utility_RowIterator implements Iterator<String>, Iterable<String>
{
   private String m_Data;
   private Integer m_index = 0;
   private String m_rowDelimiter = '\n';
    
   public Utility_RowIterator(String fileData)
   {
      m_Data = fileData; 
   }
   public Utility_RowIterator(String fileData, String rowDelimiter)
   {
      m_Data = fileData; 
      m_rowDelimiter = rowDelimiter;
   }
    
   public Boolean hasNext()
   {
      return m_index < m_Data.length() ? true : false;
   }
   public String next()
   {     
      Integer key = m_Data.indexOf(m_rowDelimiter, m_index);
       
      if (key == -1)
        key = m_Data.length();
             
      String row = m_Data.subString(m_index, key);
      m_index = key + 1;
      return row;
   }
   public Iterator<String> Iterator()
   {
      return this;   
   }
}