FORM function in Red/System (improved version)

form.reds

Red/System [
	Title:		"Form"
	Purpose:	{formats an integer in a c-string, as signed decimal or as hex}
	Author:		"Rudolf W. MEIJER"
	File:		%form-number.reds 
	Version:	0.7
	Date:		27-May-2011
	Notes: 		{Improved version, not final}
]

#include %stringf.reds

form-signed: func [
	i [integer!]
	return: [c-string!]
	/local s [c-string!] r [c-string!] c [integer!] n [logic!]
][
	if zero? i [return "0"]
	s: make-string 11
	n:  negative? i
	if n [i: negate i]
	c: 11
	while [i <> 0][
		s/c: #"0" + (i // 10)
		i: i / 10
		c: c - 1
	]
	if n [s/c: #"-" c: c - 1]
	r: copy-part s + c 11 - c
	free s
	r
]

form-hex: func [
	i [integer!]
	return: [c-string!]
	/local s [c-string!] r [c-string!] c [integer!] d [integer!]
][
	if zero? i [return "0"]
	s: make-string 8
	c: 8
	while [i <> 0][
		d: i // 16
		if d > 9 [d: d + 7]		; 7 = (#"A" - 1) - #"9"
		s/c: #"0" + d
		i: i / 16
		c: c - 1
	]
	r: copy-part s + c 8 - c
	free s
	r
]

Function 'form-hex will be surely useful to print memory addresses for debugging purpose.

I suspect form-signed may give an incorrect result when printing -2147483648 as the number currently cannot be properly negated.

Peter is right, form-signed -2147483648 gives -./,),(-*,( as result.

Rudolf, I did a quick patch in Red/System's runtime to cop with printing -2147483648 in commit 3424bcbb in the modified version of your form-signed function. If you have any proposition to improve my hardcoded version, let me know.