I have the same problem from a Java perspective. Textastic seems a good editor, but of course compiling is remote, you can only fetch and push back one file at a time, completely hopeless for any project of any size, and of course compiling or running anything is out of the question.
iOS may be becoming enough computer for more people (allegedly), but if you're a coder, no, not even close. You can code *through* it, essentially by using it as a dumb terminal, but not *on* it, not realistically.