Abstract: In a computer system, input strings to be translated are composed of characters selected from a first alphabet. According to a predetermined criterion, a list of sub-strings is selected from the input strings to form entries in a dictionary. The entries of the dictionary are arranged according to a collating order of the first alphabet. An interval including the sub-strings of the input strings is partitioned into an all-inclusive and disjoint set of ranges. The sub-strings of the interval are arranged according to the collating order of the first alphabet, and each sub-strings of a particular range has a common prefix, the common prefix selected from the list of sub-strings. A unique encoding is assigned to each common prefix, the corresponding set of unique encodings composed of characters selected from a second alphabet. The input strings are parsed, one at the time, into a plurality of tokens, each token corresponding to a sub-string selected from the dictionary.

Abstract: The invention is a compression method which provides the advantages of run-length compression while preserving the natural collating order of the data. The method of the invention replaces sequential repetitions of a target pattern beyond a threshold value followed by a single number which encodes both the repetition count and the collating relationship between the target pattern and the pattern which follows it in the uncollated sequence. In the preferred embodiment of the invention, the code is preceded by at least one repetition of the pattern. In the preferred embodiment of the invention, the numerical code is set as the difference between the run count and the threshold count if the following pattern is less than the target pattern, or if there is no following pattern. If the following pattern is greater than the compression sequence, the code is set as a predetermined number, preferably the maximum binary value of the sequence length, minus the difference between the run count and the threshold count.