+++ /dev/null
-;;; mail-header.el --- Mail header parsing, merging, formatting
-
-;; Copyright (C) 1996 by Free Software Foundation, Inc.
-
-;; Author: Erik Naggum <erik@arcana.naggum.no>
-;; Keywords: tools, mail, news
-
-;; This file is part of GNU Emacs.
-
-;; GNU Emacs is free software; you can redistribute it and/or modify
-;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation; either version 2, or (at your option)
-;; any later version.
-
-;; GNU Emacs is distributed in the hope that it will be useful,
-;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-;; GNU General Public License for more details.
-
-;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING. If not, write to
-;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
-
-;;; Commentary:
-
-;; This package provides an abstraction to RFC822-style messages, used in
-;; mail news, and some other systems. The simple syntactic rules for such
-;; headers, such as quoting and line folding, are routinely reimplemented
-;; in many individual packages. This package removes the need for this
-;; redundancy by representing message headers as association lists,
-;; offering functions to extract the set of headers from a message, to
-;; parse individual headers, to merge sets of headers, and to format a set
-;; of headers.
-
-;; The car of each element in the message-header alist is a symbol whose
-;; print name is the name of the header, in all lower-case. The cdr of an
-;; element depends on the operation. After extracting headers from a
-;; message, it is a string, the value of the header. An extracted set of
-;; headers may be parsed further, which may turn it into a list, whose car
-;; is the original value and whose subsequent elements depend on the
-;; header. For formatting, it is evaluated to obtain the strings to be
-;; inserted. For merging, one set of headers consists of strings, while
-;; the other set will be evaluated with the symbols in the first set of
-;; headers bound to their respective values.
-
-;;; Code:
-
-(require 'cl)
-
-;; Make the byte-compiler shut up.
-(defvar headers)
-
-(defun mail-header-extract ()
- "Extract headers from current buffer after point.
-Returns a header alist, where each element is a cons cell (name . value),
-where NAME is a symbol, and VALUE is the string value of the header having
-that name."
- (let ((message-headers ()) (top (point))
- start end)
- (while (and (setq start (point))
- (> (skip-chars-forward "^\0- :") 0)
- (eq (char-after) ?:)
- (setq end (point))
- (progn (forward-char)
- (> (skip-chars-forward " \t") 0)))
- (let ((header (intern (downcase (buffer-substring start end))))
- (value (list (buffer-substring
- (point) (progn (end-of-line) (point))))))
- (while (progn (forward-char) (> (skip-chars-forward " \t") 0))
- (push (buffer-substring (point) (progn (end-of-line) (point)))
- value))
- (push (if (cdr value)
- (cons header (mapconcat #'identity (nreverse value) " "))
- (cons header (car value)))
- message-headers)))
- (goto-char top)
- (nreverse message-headers)))
-
-(defun mail-header-extract-no-properties ()
- "Extract headers from current buffer after point, without properties.
-Returns a header alist, where each element is a cons cell (name . value),
-where NAME is a symbol, and VALUE is the string value of the header having
-that name."
- (mapcar
- (lambda (elt)
- (set-text-properties 0 (length (cdr elt)) nil (cdr elt))
- elt)
- (mail-header-extract)))
-
-(defun mail-header-parse (parsing-rules headers)
- "Apply PARSING-RULES to HEADERS.
-PARSING-RULES is an alist whose keys are header names (symbols) and whose
-value is a parsing function. The function takes one argument, a string,
-and return a list of values, which will destructively replace the value
-associated with the key in HEADERS, after being prepended with the original
-value."
- (dolist (rule parsing-rules)
- (let ((header (assq (car rule) headers)))
- (when header
- (if (consp (cdr header))
- (setf (cddr header) (funcall (cdr rule) (cadr header)))
- (setf (cdr header)
- (cons (cdr header) (funcall (cdr rule) (cdr header))))))))
- headers)
-
-(defsubst mail-header (header &optional header-alist)
- "Return the value associated with header HEADER in HEADER-ALIST.
-If the value is a string, it is the original value of the header. If the
-value is a list, its first element is the original value of the header,
-with any subsequent elements being the result of parsing the value.
-If HEADER-ALIST is nil, the dynamically bound variable `headers' is used."
- (cdr (assq header (or header-alist headers))))
-
-(defun mail-header-set (header value &optional header-alist)
- "Set the value associated with header HEADER to VALUE in HEADER-ALIST.
-HEADER-ALIST defaults to the dynamically bound variable `headers' if nil.
-See `mail-header' for the semantics of VALUE."
- (let* ((alist (or header-alist headers))
- (entry (assq header alist)))
- (if entry
- (setf (cdr entry) value)
- (nconc alist (list (cons header value)))))
- value)
-
-(defsetf mail-header (header &optional header-alist) (value)
- `(mail-header-set ,header ,value ,header-alist))
-
-(defun mail-header-merge (merge-rules headers)
- "Return a new header alist with MERGE-RULES applied to HEADERS.
-MERGE-RULES is an alist whose keys are header names (symbols) and whose
-values are forms to evaluate, the results of which are the new headers. It
-should be a string or a list of string. The first element may be nil to
-denote that the formatting functions must use the remaining elements, or
-skip the header altogether if there are no other elements.
- The macro `mail-header' can be used to access headers in HEADERS."
- (mapcar
- (lambda (rule)
- (cons (car rule) (eval (cdr rule))))
- merge-rules))
-
-(defvar mail-header-format-function
- (lambda (header value)
- "Function to format headers without a specified formatting function."
- (insert (capitalize (symbol-name header))
- ": "
- (if (consp value) (car value) value)
- "\n")))
-
-(defun mail-header-format (format-rules headers)
- "Use FORMAT-RULES to format HEADERS and insert into current buffer.
-FORMAT-RULES is an alist whose keys are header names (symbols), and whose
-values are functions that format the header, the results of which are
-inserted, unless it is nil. The function takes two arguments, the header
-symbol, and the value of that header. If the function itself is nil, the
-default action is to insert the value of the header, unless it is nil.
-The headers are inserted in the order of the FORMAT-RULES.
-A key of t represents any otherwise unmentioned headers.
-A key of nil has as its value a list of defaulted headers to ignore."
- (let ((ignore (append (cdr (assq nil format-rules))
- (mapcar #'car format-rules))))
- (dolist (rule format-rules)
- (let* ((header (car rule))
- (value (mail-header header)))
- (cond ((null header) 'ignore)
- ((eq header t)
- (dolist (defaulted headers)
- (unless (memq (car defaulted) ignore)
- (let* ((header (car defaulted))
- (value (cdr defaulted)))
- (if (cdr rule)
- (funcall (cdr rule) header value)
- (funcall mail-header-format-function header value))))))
- (value
- (if (cdr rule)
- (funcall (cdr rule) header value)
- (funcall mail-header-format-function header value))))))
- (insert "\n")))
-
-(provide 'mailheader)
-
-;;; mail-header.el ends here
projects / gnus / blobdiff