1. A method comprising: generating a sequence of tokens, each token being an integer representation of a respective sequence of characters that is included in a style sheet, each token corresponding to a respective character position that indicates a position of that token in the style sheet; identifying a designated token in the sequence of tokens that includes a user-initiated change, the designated token following a first subset of the tokens in the sequence of tokens and preceding a second subset of the tokens in the sequence of tokens; determining whether the user-initiated change is identified as a type of change that changes no attributes, other than the character positions, of the tokens in the second subset of the tokens; and determining whether the second subset of the tokens is to be re-tokenized, including: determining that the second subset of the tokens is not to be re-tokenized if the user-initiated change is identified as a type of change that changes no attributes, other than the character positions, of the tokens in the second subset of the tokens, but determining that the second subset of the tokens is to be re-tokenized if the user-initiated change is not identified as a type of change that changes no attributes, other than the character positions, of the tokens in the second subset of the tokens.