Form-based formula editing in spreadsheets

A method comprising:

• displaying at least a portion of a formula in a user interface to a spreadsheet, wherein the portion of the formula comprises a character string;
• identifying one or more functions expressed in the character string;
• displaying a form in the user interface, wherein the form includes fields corresponding to parameters of an active one of the one or more functions expressed in the character string;
• populating the character string at positions corresponding to the parameters of the active one, of the one or more functions, with values entered into the fields of the form;
• and
• as the active one, of the one or more functions, changes to a newly active function, changing the fields in the form to correspond to parameters of the newly active function;
• wherein the newly active function comprises a nested function added by a direct edit of the character string outside of the form;
• and
• wherein the active one, of the one or more functions, changes to the nested function upon completion of the direct edit of the character string.

A computing apparatus comprising:

• one or more computer readable storage media;
• a processing system operatively coupled to the one or more computer readable storage media;
• and
• program instructions stored on the one or more computer readable storage media that, when executed by the processing system, direct the computing apparatus to at least:
• in a user interface layer of an application, receive input comprising text entered into a cell of a spreadsheet;
• in a parsing layer of the application, detect a function in the text and identifying the function to the user interface layer;
• in the user interface layer, surface a form comprising one or more fields corresponding to one or more parameters of the function;
• in the user interface layer, receive subsequent user input comprising subsequent text entered into a field of the form;
• in the parsing layer of the application, detect a nested function in the subsequent text and identifying the nested function to the user interface layer;
• and
• in the user interface layer, surface one or more fields corresponding to one or more parameters of the nested function.