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use "types.use"
use "utf.use"
use "chartype.use"

pkg std =
	const strstrip	: (str : byte[:] -> byte[:])
	const strfstrip	: (str : byte[:] -> byte[:])
	const strrstrip	: (str : byte[:] -> byte[:])
;;

/* strip blanks from both head and tail of str */
const strstrip = {str
	-> strrstrip(strfstrip(str))
}

/* strip forward on str */
const strfstrip = {str
	var c
	
	for c = decode(str); isblank(c); c = decode(str)
		str = str[charlen(c):]
	;;
	-> str

}

/* strip reverse on str */
const strrstrip = {str
	var i
	var end

	/* scan backwards for start of utf8 char */
	end = str.len
	for i = str.len; i != 0; i--
		if str[i - 1] & 0x80 == 0 || str[i-1] & 0xc0 != 0x80
			if !isspace(decode(str[i-1:]))
				break
			;;
			end = i - 1
		;;
	;;
	-> str[:end]
}