Re: [O] make orgtbl-ascii-plot easier to install

[Nicolas Goaziou]

Hello,

Thierry Banel <address@hidden> writes:

> Sorry for the late answer, I was on the road.
> The patch is attached hereafter.

Thank you for the patch. Some comments follow.

> From 5fddaba2208c2cb4ce3b6bc24d0d10571124fb39 Mon Sep 17 00:00:00 2001
> From: Thierry Banel <address@hidden>
> Date: Mon, 11 Aug 2014 00:00:21 +0200
> Subject: [PATCH]      * org-table.el: add ascii plotting in tables, 
>  (orgtbl-ascii-plot): top-level function 
>  (orgtbl-ascii-draw),         (orgtbl-uc-draw-grid), 
>  (orgtbl-uc-draw-cont): helper functions which go in table

If they are helper functions, I suggest to use "--" in their name, e.g.,
`orgbtl--ascii-draw'.

> +(defun orgtbl-ascii-draw (value min max &optional width characters)
> +  "Draws an ascii bar in a table.
> +VALUE is a the value to plot, the width of the bar to draw.
> +A value equal to MIN will be displayed as empty (zero width bar).
> +A value equal to MAX will draw a bar filling all the WIDTH.
> +WIDTH is the expected width in characters of the column.
> +CHARACTERS is a string of characters that will compose the bar,

This is a minor issue, but a "string of characters" sounds strange:
aren't all strings constituted of characters? Maybe you really want
a list of characters.

> +with shades of grey from pure white to pure black.
> +It defaults to a 10 characters string of regular ascii characters.
> +"

Spurious newline at the end of the docstring.

> +  (unless characters (setq characters " .:;c!lhVHW"))
> +  (unless width (setq width 12))

I suggest let-binding variables instead:

  (let ((characters (or characters " .:;c!lhvHW"))
        (width (or width 12))))

> +  (if (stringp value)
> +      (setq value (string-to-number value)))

Prefer `and' or `when' over one-armed `if'.  Also, this may be dangerous
since `string-to-number' can return funny values.  Why wouldn't you
simply forbid strings and limit VALUE to integers.

> +  (setq value (* (/ (- (+ value 0.0) min) (- max min)) width))

(let ((value ...)))

> +  (cond
> +   ((< value     0) "too small")
> +   ((> value width) "too large")
> +   (t
> +    (let ((len (1- (length characters))))
> +      (concat
> +       (make-string (floor value) (elt characters len))
> +       (string (elt characters
> +                 (floor (* (- value (floor value)) len)))))))))
> +
> +(defun orgtbl-uc-draw-grid (value min max &optional width)
> +  "Draws an ascii bar in a table.
> +It is a variant of orgtbl-ascii-draw with Unicode block characters,
> +for a smooth display.
> +Bars appear as grids (to the extend the font allows).
> +"

Spurious newline. I wouldn't put the last sentence on its own line, too.
Also, isn't it "extent"?

> +(defun orgtbl-uc-draw-cont (value min max &optional width)
> +  "Draws an ascii bar in a table.
> +It is a variant of orgtbl-ascii-draw with Unicode block characters,
> +for a smooth display.
> +Bars are solid (to the extend the font allows).
> +"

Ditto.

> +  (orgtbl-ascii-draw value min max width " 
> \u258F\u258E\u258D\u258C\u258B\u258A\u2589\u2588"))
> +
> +;;;###autoload
> +(defun orgtbl-ascii-plot (&optional ask)
> +  "Draws an ascii bars plot in a column, out of values found in another 
> column.
> +A numeric prefix may be given to override the default 12 characters wide 
> plot.
> +"

You must refer explicitly to ASK in your docstring. In particular, you
may want to detail the distinction between '(4) and 4.

Spurious newline too.

> +  (interactive "P")
> +  (let ((col (org-table-current-column))
> +     (min  1e999)

`most-positive-fixnum'

> +     (max -1e999)

`most-negative-fixnum'

> +     (length 12)
> +     (table (org-table-to-lisp)))
> +    (cond ((consp ask)
> +        (setq length
> +              (or
> +               (read-string "Length of column [12] " nil nil 12)
> +               12)))
> +       ((numberp ask)
> +        (setq length ask)))

(let ((length (cond ((consp ask)
                     (read-number "Length of column [12] " nil nil 12))
                    ((numberp ask) ask)
                    (t 12)))))

> +    (mapc

Small nitpick: I suggest to use `dolist' instead of `mapc' (no funcall
overhead).

> +     (lambda (x)
> +       (when (consp x)
> +      (setq x (nth (1- col) x))
> +      (when (string-match
> +             "^[-+]?\\([0-9]*[.]\\)?[0-9]*\\([eE][+-]?[0-9]+\\)?$"
> +             x)

Would `org-table-number-regexp' make sense here instead of the
hard-coded regexp?

> +        (setq x (string-to-number x))
> +        (if (> min x) (setq min x))
> +        (if (< max x) (setq max x)))))

(when (> min x) ...)
(when (< max x))

> +     (or (memq 'hline table) table)) ;; skip table header if any

This check is not sufficient in the following cases:

  |-----------|
  | no header |
  |-----------|

and

  |----------|
  |  header  |
  |----------|
  | contents |

IOW, you need to eliminate the leading 'hline, if any, and skip until
the next 'hline if there is one and if there is something after it.


Regards,

-- 
Nicolas Goaziou