Hex to decimal

Hi everybody,

Fixing up my hex to decimal converter. Anybody know a good easy way to make this case insensitive. I thought of changing the characters to match the characters in the passed set of base numbers, but that would add too much. Making two sets of base numbers is also a bit to much. I’m thinking that the subroutine might have to be more specific in what it handles.

property hex_chars : "0123456789ABCDEF"
set h to "AF"
BaseToDec(h, hex_chars)
-- converts a base string to decimal integer
-- case sensetive because of the offset command
on BaseToDec(h, base_chars)
	set m to length of base_chars
	set n to 0
	set i to -1
	repeat with this_char in reverse of characters of h
		set i to i + 1
		set o to (offset of this_char in base_chars)
		if o is 0 then
			set n to 0
			exit repeat
		end if
		set char_val to o - 1
		set n to n + char_val * (m ^ i)
	end repeat
	return n
end BaseToDec


Hi kel,

on my machine your routine works with both uppercase and lowercase letters.

If speed doesn’t matter, I use this perl command for conversion

set nHex to "03E8"
set nDec to (do shell script "perl -e 'printf(hex(\"" & nHex & "\"))'") as number --> 1000

Hi Stefan,

Wow! You mean ‘offset’ is case insensitive on your machine?

I was thinking about checking if AppleScript’s text item delimiters could be made case insensitive with ‘ignoring case’. I need to check that out.


AppleScript’s text item delimiters are case insensitive when you coerce the text to Unicode text

Hi Stefan,

That works! I didn’t know that. Here’s what I’ll use then:

set t to "0123456789abcdef" as Unicode text
set utid to AppleScript's text item delimiters
set AppleScript's text item delimiters to "F"
set temp_l to text items of t
set AppleScript's text item delimiters to utid
set char_val to (count item 1 of temp_l)

Thanks a lot,

Some time ago (can’t find it) Nigel posted this version which will deal with signed hex:

on hexToNum from h given sign:sign
	script o
		property hexChrs : "0123456789abcdef" as Unicode text -- TIDs are case insensitive with Unicode.
		on getHexVal(c)
			set AppleScript's text item delimiters to c
			set v to (count text item 1 of hexChrs)
			if (v is 16) then error "Non-hex character(s)."
			return v
		end getHexVal
	end script
	set astid to AppleScript's text item delimiters
		set h to h as Unicode text -- Speeds up use of TIDs with Unicode 'hexChrs' in o.
		tell o to set n to getHexVal(character 1 of h)
		if (sign) and (n > 7) then set n to n - 16
		repeat with i from 2 to (count h)
			tell o to set n to n * 16 + getHexVal(character i of h)
		end repeat
	on error msg number errNum
		set AppleScript's text item delimiters to astid
		error "hexToNum handler: " & msg number errNum
	end try
	set AppleScript's text item delimiters to astid
	return n
end hexToNum

hexToNum from "00000000043e9207" without sign
--> 71209479

hexToNum from "FFFE" without sign
--> 65534

hexToNum from "FFFE" with sign
--> -2

On both my machines, TIDs are case sensitive when the main text is a string, but obey the current setting of the case attribute (‘considering case’ or ‘ignoring case’) when the main text is Unicode.

On my Jaguar machine, ‘offset of’ is case sensitive with both strings and Unicode text. On my Tiger machine, it obeys the case attribute with both strings and Unicode text.

The class of the delimiter or of the searched-for substring can be either string or Unicode text without affecting the result.

Confused? :slight_smile:

It was one of the contributions to Hexadecimal <–> Decimal Conversion in Code Exchange.

Hi Adam and Nigel,

Great, we were on the right track. I remember that handler now, but maybe didn’t catch the unicode text case sensitivity part.