drac – Declare active character substitution, robustly

The pack­age pro­vides macros \De­clareRo­bustAc­tChar and \ReDe­clareRobAc­tChar. One uses \De­clareRo­bustAc­tChar in the same way one would use \De­clareRo­bustCom­mand; the macro \pro­tects the ac­tive char­ac­ter when it ap­pears in a mov­ing ar­gu­ment. \ReDe­clareRobAc­tChar re­de­fines an ac­tive char­ac­ter pre­vi­ously de­fined with \De­clareRo­bustAc­tChar, in the same way that \re­new­com­mand works for or­di­nary com­mands.