Generative literature, defined as the production of continuously changing literary texts by means of a specific dictionary, some set of rules and the use of algorithms, is a very specific form of digital literature which is completely changing most of the concepts of classical literature. Texts being produced by a computer and not written by an author, require indeed a very special way of engrammation and, in consequence, also point to a specific way of reading particularly concerning all the aspects of the literary time. In my paper, I will try to present some of the characteristics of generative texts and their consequences for the conception of literature itself. I call "engrammation" the adaptation of expression wills to the technical constraints of the medium used for its mediatisation. For instance, a book needs a fixed writing, and the mediatisation by means of a screen needs other modalities of presentation.