zsh
stores its prompt setups and defintions in
/usr/share/zsh/functions/Prompts/
So if you want to take a look what prompt clint does behind the curtains, first find the right file.
$ ls /usr/share/zsh/functions/Prompts/clint
/usr/share/zsh/functions/Prompts/prompt_clint_setup
And open it in your favorite text editor.