bibtex-map-entries is a compiled Lisp function in `bibtex.el'.

(bibtex-map-entries FUN)

Call FUN for each BibTeX entry in buffer (possibly narrowed).
FUN is called with three arguments, the key of the entry and the buffer
positions of beginning and end of entry. Also, point is at beginning of
entry and `match-data' corresponds to the header of the entry,
see regexp `bibtex-entry-head'. If `bibtex-sort-ignore-string-entries'
is non-nil, FUN is not called for @String entries.