Indeed. Text is "unreasonably efficient" in this case. Passing a struct is easy enough in go, but that's all it can do for you. So you'd have to pass arguments like PLClauseList{PLLoadClause{...}, ..., PLFact{Head: PLAtom{"human"}, Arguments: PLArgList{PLAtom{"socrates"}}}, ...}. Unwieldy, unreadable, and hard to edit.