Your comments

Word completion rather than code completion would be a more generic solution. Vim and Textmate both provide similar features. The Vim version is superior as it uses a dictionary of words derived from all open buffers, not just the current file. Given the difficulty of typing on the iPad, this would save a huge number of keystrokes without needing so much setup with Textexpander. Not sure how you would decide which files to base the completion dictionary on however - perhaps all in the current folder ? Even if it was just the currently open file that would be a win.