FileMaker Pro Custom Functions

// XORbin ( bin0 ; bin1 ; result ) // returns the XOR of two binary numbers. // the intitial value of result must be empty ("") // the function returns ? if bin0 or bin1 are empty or non-binary // // written by Vaughan Bromfield // vbromfield@optusnet.com.au // 14 March 2010 Let( [ exp1 = Case( Length( bin0 ) ≥ Length( bin1 ) ; bin0 ; bin1 ) ; pad0s = Filter( 10 ^ Length( exp1 ) ; "0" ) ; exp2 = Right( pad0s & Case( Length( bin0 ) < Length( bin1 ) ; bin0 ; bin1 ) ; Length( exp1 ) ) ; n = Length( result ) + 1 ] ; Case( Filter( bin0 ; "01" ) ≠ bin0 or Filter( bin1 ; "01" ) ≠ bin1 ; "?" ; // exit invalid parameters IsEmpty( bin0 ) or IsEmpty( bin1 ) ; "?" ; // exit empty parameters Length( result ) = Length( exp1 ) ; result ; // exit result completed XORbin ( bin0 ; bin1 ; result & ( Middle ( exp1 ; n ; 1 ) xor Middle ( exp2 ; n ; 1 ) ) ) ) // end case ) // end let
 Then copy & paste into FileMaker Advanced's Edit Custom Function window.