16. A computer program product for inserting delimiters into a formula, the computer program product being embodied in a non-transitory computer readable medium and comprising computer instructions for: successively receiving a plurality of selections of cells while in a formula editing mode in a host cell into which a formula is being entered; automatically determining a current context of the formula with respect to which the selections are received; and automatically inserting a first delimiter type between references to the cells inserted into the formula in response to receiving the plurality of selections when the current context comprises a first context and automatically inserting a second delimiter type between references inserted into the formula in response to receiving the plurality of selections when the current context comprises a second context, wherein each first and second delimiter type spatially separates the references to the cells from each other within the formula by being inserted between the references to the cells.
21. A computer program product as recited in claim 16 , wherein the first context and the second context are included in a set of contexts of formulas and wherein each context in the set is associated with a default delimiter type.