cl-xml/cl-xml.lisp

67 lines
2.2 KiB
Common Lisp

;;;; cl-xml.lisp
;(in-package #:cl-xml)
(declaim (optimize (debug 3)))
(defun tagp (exp)
(symbolp (car exp)))
(defun print-contents (contents indentation stream)
(mapc (lambda (s) (format stream "~a~a~%" indentation s)) contents))
(defun next-tags (list)
(cond ((null list) nil)
((eq 'cons (type-of (car list))) list)
(t (next-tags (cdr list)))))
(defun handle-keywords (keywords)
(cond ((or (null keywords)
(consp (car keywords)))
"")
((keywordp (car keywords))
(format nil " ~a=\"~a\"~a"
(string-downcase (symbol-name (car keywords)))
(cadr keywords)
(handle-keywords (cddr keywords))))))
(defun indentation (level)
(labels ((create-indentation-string (count)
(if (= count 0)
'()
(cons " " (create-indentation-string (1- count))))))
(let ((spaces (create-indentation-string level)))
(if (null spaces)
""
(reduce (lambda (s1 s2) (concatenate 'string s1 s2))
spaces)))))
(defun sexp-to-xml (sexp indentation-level &optional (stream t))
(cond ((null sexp) nil)
((stringp (car sexp)) (print-contents sexp (indentation indentation-level) stream))
((consp (car sexp))
(sexp-to-xml (car sexp) (1+ indentation-level) stream)
(sexp-to-xml (cdr sexp) indentation-level stream))
((tagp sexp)
(let ((tag-name (string-downcase (symbol-name (car sexp))))
(spaces (indentation indentation-level)))
(format stream "~a<~a~a>~%"
spaces
tag-name
(handle-keywords (cdr sexp)))
(let ((next-tags (next-tags (cdr sexp))))
(unless (null next-tags)
(sexp-to-xml next-tags (1+ indentation-level) stream)))
(format stream "~a</~a>~%" spaces tag-name)))))
(defmacro xml (form)
(sexp-to-xml form 0))
(defun sexp-to-xml-string (form)
(with-open-stream (stream (make-string-output-stream))
(sexp-to-xml form 0 stream)
(get-output-stream-string stream)))
(defmacro xml-string (form)
(sexp-to-xml-string form))