length-string-unit-part
Name
length-string-unit-part -- Returns the unit part of a length string
Synopsis
(length-string-unit-part lenstr)
Description
Given a length as a string, return the units part.
Example
"100pt" returns "pt". "30" returns "".  
"in" returns "in".
Author
Norman Walsh, <ndw@nwalsh.com>
Source Code
(define (length-string-unit-part lenstr)
  ;; Returns the unit part of a length string
  (let ((number-part (length-string-number-part lenstr))
	(strlen (string-length lenstr)))
    (if (equal? (string-length number-part) strlen)
	""
	(substring lenstr (string-length number-part) strlen))))