There is a fairly active research field in computational linguistics for Authorship Attribution and Native Language Identification. These try to identify a spec

There is a fairly active research field in computational linguistics for Authorship Attribution and Native Language Identification. These try to identify a specific person or a persons first language by idioms in their writing style. I have seen some people apply similar techniques to code (eg identify authorship of malware) and I assume what you're asking would be a pretty simple variation of that.