1. A method for inferring a sequence of editing operations that were applied to a document to produce an updated version of the document, comprising: determining a minimum edit distance between the document and the updated version of the document; wherein determining the minimum edit distance involves associating a block cost with each contiguous block of characters that is changed by an editing operation associated with the minimum edit distance; and using information stored while determining the minimum edit distance to determine the sequence of editing operations, including changes to contiguous blocks of characters, which were used to achieve the minimum edit distance.