;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;                                                                        	;
;         =.lsp   By Michael Bulatovich    March 29th, 2002                	;
;                    www.michaelbulatovich.ca                                   ;
;                                                                          	;
;         Converts feet and inches to meters or millimeters transparently. 	;
;         For use in any command that requires a distance in a             	;
;         metric drawing, and where the balding head of the user thinks    	;
;         better in imperial units.                                        	;
;                                                                          	;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defun pickunits (/)
  (initget 1 "1 2")
  (setq	conversiontype
	 (getkword
	   "\nSpecify Metric Units: <1> Meters | <2> Millimeters"
	 )
  )
)
;-------------------------------------------------------------------------------
(defun convert (arg / num)
  (if (eq conversiontype "1")
    (setq arg (* arg 0.0254))
    (setq arg (* arg 0.254))
  )
)
;------------------------------------------------------------------------------
(defun str-index (target search
		     / tarlen serlen cntr strlist place sersub tarsub tlen-1)

  
  (setq	tarlen (strlen target)
	serlen (strlen search))
  
  (if (<= 1 tarlen serlen);if search is greater r eaqual to first, likewise target to 1
    (progn
      (setq tarsub	(substr target tarlen 1)
	    tlen-1	(1- tarlen);
      )
      (setq strlist nil					;initialize a nil variable
	    cntr 0) 					;set a cntr to zero
      (while (< (setq cntr (1+ cntr)) tarlen);bump cntr by one, as ong as its less than the search item length
	(setq strlist (cons (cons (substr target cntr 1) (- tarlen cntr)) strlist))
      );construct a assoc-list of characters with their inverse positions
      
      (setq cntr tarlen)
      (while (<= 1 cntr serlen)
	(setq cntr	(if (or	(/= (setq sersub (substr search cntr 1)) tarsub)
			(/= (substr search (- cntr tlen-1) tarlen) target)
		    )					;end or
		  (+ cntr
		     (if (setq place (assoc sersub strlist))
		       (cdr place) tarlen)
		     )					;end then
		  (- tlen-1 cntr)				;end else
		)					;end if
	)				;negative value for ending(?)
      )							;end while
      					;;return position or nil
      (if (< cntr 0)(- cntr))
    );end progn
  );end if
  
);end defun
;------------------------------------------------------------------------------
(defun c:= (/ input footindex feet total trim inches strlength)
  (setvar "cmdecho" 0)
  (prompt "\nConvert Imperial units to Metric units. ")
  (if (equal conversiontype nil)
    (pickunits)
  )
  (setq total 0.0)

  (setq input (getstring "Specify Imperial dimension:"))
								; get the imperial

  (setq footindex (str-index "'" input))
								; find the foot mark
  (if (not (eq nil footindex))					; if feet were entered
    (progn							; then...
      (setq feet (substr input 1 footindex)) 			;isolate the feet
      (setq total (* 12 (atof feet)))				; convert the string
      (setq inches (substr input (+ 2 footindex))) 		;isolate the inches
      (setq strlength (strlen inches))				;set strlenght
      (if (eq strlength 0)					; if its zero
	(convert total)
	(progn							;if its not zero
	  (setq trim (- strlength 1))
	  (if (eq "\"" (substr inches strlength 1))
								;and if it ends in "
	    (setq inches (substr inches 1 trim)) 		;cut it off
	  )


	  (setq total (+ total (atof inches)))
								;convert and add to total
	  (convert total)
	)
      )

    )								;end of progn
    (progn							; if no feet were entered

      (setq inches input)
      (setq strlength (strlen inches))
      (setq trim (- strlength 1))
      (if (eq "\"" (substr inches strlength 1)) 		;if it ends in a "
	(setq inches (substr inches 1 trim))
      )								; cut it off
      (setq total (+ total (atof inches))) 			;convert and add to total
      (convert total)
    )

  )								;end if


)