When I debug in Slime and inspect the value of a floating point variable, I see something like
6.8998337e-4
However, I find that very hard to read and would prefer
0.00068998337
How can I achieve that?
First:
CL-USER> (format nil "~F" 6.8998337e-4)
"0.00068998337"
CL-USER> (format nil "~E" 6.8998337e-4)
"6.8998337e-4"
In slime/sly, when you Inspect (C-c I) the value 6.8998337e-4, you get:
#<SINGLE-FLOAT {3A34E00000000019}>
--------------------
Scientific: 6.8998337e-4
Decoded: 1.0 * 0.70654297 * 2^-10
Digits: 24
Precision: 24
The "Scientific" value is formatted in swank/slynk in contrib/swank-fancy-inspector.lisp or contrib/slynk-fancy-inspector.lisp :
(defmethod emacs-inspect ((f float))
(cond
((float-nan-p f)
;; try NaN first because the next tests may perform operations
;; that are undefined for NaNs.
(list "Not a Number."))
((not (float-infinity-p f))
(multiple-value-bind (significand exponent sign) (decode-float f)
(append
`("Scientific: " ,(format nil "~E" f) (:newline)
"Decoded: "
(:value ,sign) " * "
(:value ,significand) " * "
(:value ,(float-radix f)) "^"
(:value ,exponent) (:newline))
(label-value-line "Digits" (float-digits f))
(label-value-line "Precision" (float-precision f)))))
((> f 0)
(list "Positive infinity."))
((< f 0)
(list "Negative infinity."))))
You could modify emacs-inspect method and change (format nil "~E" f) to (format nil "~F" f), or you could shadow emacs-inspect with an emacs-inspect :around method to modify the behavior to use "~F".