;;; hash-csv.l
;;; Ver.1.0.3.20110119
;;; 2006-12-21, 2011-01-19
;;; Public Domain
;;; http://purl.com/net/dkcc/shed/hash-table-to-csv.html

(provide "hash-csv")
(in-package "editor")
(export '(hash-table-to-csv hash-table-all-entries count-chars))

(defun hash-table-to-csv (table &key (quotes t) (princ t) (header "key,val") (output-buffer "*hash-csv*")
                                &aux (field-string (if princ "~A" "~S"))
                                output-string so)
  "Convert hash table into csv in *hash-csv* buffer.
This csv format may conform to RFC 4180. It means every double-quotes are automatically escaped by another double-quotes.
Usage: (hash-table-to-csv table :quotes nil :princ nil :header \"No.,key,val\" :output-buffer \"*hash2csv*\")
    quotes: When t, each field is enclosed in double-quotes.
            Even if nil, fields which contain commas, line breaks or double-quotes are enclosed in double-quotes.
    princ: Print type of each field. When t, print type is ~A. When nil, ~S.
    header: The first line of csv. header must contains one comma (= two fields).
            You can also set header nil to omit the header line.
    output-buffer: The name of output buffer. When nil, output will go to *standard-output*.
Note: When a field contains commas, line breaks or double-quotes, you should set quote t for a valid format."
  (interactive "Shash-table: ")
  (when (symbolp table) (setq table (eval table)))
  (if (null output-buffer)
      (setq so *standard-output*)
    (progn
      (unless (prog1 (find-buffer output-buffer)
                (setq so (make-buffer-stream (switch-to-buffer output-buffer))))
        (make-local-variable 'need-not-save)
        (setq need-not-save t)
        (when (find-symbol "csv-mode" "editor") (csv-mode)))
      (delete-region (point-min) (point-max))))
;;;  (with-output-to-selected-buffer
;;;  (with-output-to-temp-buffer (bo nil)
   (when header (format so "~A~%" header))
   (maphash
    (lambda (key val)
      (format so "~{~A~^,~}~%"   ; "~A" is needed because output-string may contain control string
              (mapcar
               (lambda (field)
                 (setq output-string (quote-string (format nil field-string field) #\" #\"))
                 (if (or quotes (string-match "[\",\n]" output-string))
                     (concat "\"" output-string "\"")
                   output-string))
               (list key val))))
    table)
  so)
;;; e.g. (hash-table-to-csv *ss-ghost-table*)

(defun hash-table-all-entries (table &key (quotes t) (princ t))
  "Print all keys and values of a hash table."
  (hash-table-to-csv table :quotes quotes :princ princ :output-buffer nil))

(defun count-chars (&key (input-buffer (selected-buffer)) (point (point-min)) (output-buffer "*count-chars*") quotes)
  "Count characters in the current buffer."
  (interactive)
  (save-excursion
    (long-operation
      (with-input-from-buffer (input-buffer point)
        (let ((count (make-hash-table))
              char)
          (while (setq char (read-char *standard-input* nil))
            (if (gethash char count)
                (incf (gethash char count))
              (setf (gethash char count) 1)))
          (hash-table-to-csv count :princ nil :header (concat "\"" (buffer-name (selected-buffer)) "\",\"char-counts\"") :output-buffer output-buffer :quotes quotes))))))
;;; elapsed time [http://daukan.hp.infoseek.co.jp/program/outtest5-sjis.txt]: raw: 318.422s, byte-compiled: 2.454s