1. A method comprising: receiving a first sequence of text element values, determining, with one or more computing devices, a value of a following text element, wherein determining the value of the following text element comprises determining, based on the first sequence of text element values and a recurrent neural network trained with a corpus of text element values sequenced in accordance with a defined format, a probability value associated with a first text element value, wherein the probability value is related to the predictability of the first text element value following the first sequence of text element values based on a probabilistic model learned by the recurrent neural network from the corpus, comparing the probability value to a threshold, and selecting either the first text element value or a second text element value as the value of the following text element based on whether the probability value exceeds the threshold; processing, with the one or more computing devices, a second sequence of text element values with a set of instructions, the second sequence of text element values comprising the first sequence of text element values followed by the selected value of the following text element; and testing, with the one or more computing devices, a performance characteristic of the set of instructions when the set of instructions processes the second sequence of text element values.