I think the unix philosophy is the model to follow here. Design an input method just capable of receiving the information and let other applications process you

I think the unix philosophy is the model to follow here. Design an input method just capable of receiving the information and let other applications process your input. Input is also about context, in which case you need to process an input to context prior to an input in a context. Example: Context = Numeric question about integer numbers and four operators, +, - ,, / input = r'[0-9,\+,\-,\,\/]'