One problem with hash tables is that they don’t have a print representation. Thus, if you’re using rcircColoredNicks and want to look at the variable value of rcirc-color-mapping you’ll get the following:
rcirc-color-mapping is a variable defined in `rcirc-color.el'. Its value is #<hash-table 'equal nil 21/65 0x1d70b80> Documentation: Hash-map mapping nicks to color names.
Not good!
That’s why I’m using the following piece of code to look at hash tables:
(defun describe-hash (variable &optional buffer)
"Display the full documentation of VARIABLE (a symbol).
Returns the documentation as a string, also.
If VARIABLE has a buffer-local value in BUFFER (default to the current buffer),
it is displayed along with the global value."
(interactive
(let ((v (variable-at-point))
(enable-recursive-minibuffers t)
val)
(setq val (completing-read
(if (and (symbolp v)
(hash-table-p (symbol-value v)))
(format
"Describe hash-map (default %s): " v)
"Describe hash-map: ")
obarray
(lambda (atom) (and (boundp atom)
(hash-table-p (symbol-value atom))))
t nil nil
(if (hash-table-p v) (symbol-name v))))
(list (if (equal val "")
v (intern val)))))
(with-output-to-temp-buffer (help-buffer)
(maphash (lambda (key value)
(pp key)
(princ " => ")
(pp value)
(terpri))
(symbol-value variable))))
If you use it on the same variable again, you’ll get a `*Help*` buffer showing the following:
"NickServ" => (foreground-color . "deepskyblue1") "alephnull" => (foreground-color . "yellow4") "fsbot" => (foreground-color . "springgreen2") "delYsid" => (foreground-color . "springgreen3") "johnw" => (foreground-color . "turquoise2") etc.
This code is also available on the EmacsWiki HashMap page.
#Emacs