diff options
| -rw-r--r-- | lisp/textmodes/bibtex.el | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/lisp/textmodes/bibtex.el b/lisp/textmodes/bibtex.el index 0a0a58244d0..a78219e3f69 100644 --- a/lisp/textmodes/bibtex.el +++ b/lisp/textmodes/bibtex.el @@ -40,6 +40,8 @@ ;;; Code: +(require 'iso8601) + ;; User Options: @@ -2761,12 +2763,16 @@ and `bibtex-autokey-names-stretch'." (defun bibtex-autokey-get-year () "Return year field contents as a string obeying `bibtex-autokey-year-length'." - (let ((yearfield (bibtex-autokey-get-field '("year" "date")))) - ;; biblatex date field has format yyyy-mm-dd - (if (< 4 (length yearfield)) - (setq yearfield (substring yearfield 0 4))) - (substring yearfield (max 0 (- (length yearfield) - bibtex-autokey-year-length))))) + (let* ((str (bibtex-autokey-get-field '("date" "year"))) ; possibly "" + (year (or (and (iso8601-valid-p str) + (let ((year (decoded-time-year (iso8601-parse str)))) + (and year (number-to-string year)))) + ;; BibTeX permits a year field "(about 1984)", where only + ;; the last four nonpunctuation characters must be numerals. + (and (string-match "\\([0-9][0-9][0-9][0-9]\\)[^[:alnum:]]*\\'" str) + (match-string 1 str)) + (user-error "Year or date field `%s' invalid" str)))) + (substring year (max 0 (- (length year) bibtex-autokey-year-length))))) (defun bibtex-autokey-get-title () "Get title field contents up to a terminator. @@ -2849,12 +2855,12 @@ The name part: The year part: 1. Build the year part of the key by truncating the content of the year - field to the rightmost `bibtex-autokey-year-length' digits (useful - values are 2 and 4). - 2. If the year field (or any other field required to generate the key) - is absent, but the entry has a valid crossref field and - `bibtex-autokey-use-crossref' is non-nil, use the field of the - crossreferenced entry instead. + component of the date or year field to the rightmost + `bibtex-autokey-year-length' digits (useful values are 2 and 4). + 2. If both the year and date fields are absent, but the entry has a + valid crossref field and `bibtex-autokey-use-crossref' is + non-nil, use the date or year field of the crossreferenced entry + instead. The title part 1. Change the content of the title field according to |