How do I write a parser in C or Objective-C without a parser generator? <p>I am trying to make a calculator in C or Objective-C that accepts a string along the lines of</p> <pre><code>8/2+4(3*9)^2 </code></pre> <p>and returns the answer 2920. I would prefer not to use a generator like Lex or Yacc, so I want to code it from the ground up. How should I go about doing this? Other than the Dragon book, are there any recommended texts that cover this subject matter?</p>