Electronic dictionary, its production method, and index compression and decompression device

Claim 1

An electronic dictionary comprising: a dictionary medium; dictionary data composed of a plurality of dictionary data elements and stored in the dictionary medium; and an index file showing storage positions of all dictionary data elements and being stored in the dictionary medium, wherein the index file is a differential index in which each item is expressed by a differential between a pointer showing a storage position of a dictionary data element and a given function value, with each item of the differential index being expressed by a bit length equal to or shorter than maximum bit length for showing a storage position of a dictionary data element.

Claim 7

A method of producing an electronic dictionary comprising: a dictionary medium; dictionary data composed of a plurality of dictionary data elements and stored in the dictionary medium; and an index file showing storage positions of all dictionary data elements and being stored in the dictionary medium, having the steps of: dictionary data storing for storing dictionary data in an area in the dictionary medium; function calculation for calculating a prediction pointer by substituting an index number into an already stored function for predicting a pointer; differential calculation for calculating a differential between a pointer in an index file composed of pointers each showing a storage position of a dictionary data element in the dictionary medium and the prediction pointer calculated in the step of function calculation; obtaining for obtaining the differential calculated in the step of differential calculation; and data storage for storing the differential obtained in the step of obtaining in an another area in the dictionary medium.

Claim 8

A method of producing an electronic dictionary comprising: a dictionary medium; dictionary data composed of a plurality of dictionary data elements and stored in the dictionary medium; and an index file showing storage positions of all dictionary data elements and being stored in the dictionary medium, having the steps of: dictionary data storing for storing dictionary data in an area in the dictionary medium; function calculation for calculating a prediction pointer by substituting an index number into an already stored function for predicting a pointer; differential calculation for calculating a differential between a pointer in an index file composed of pointers each showing a storage position of a dictionary data element in the dictionary medium and the prediction pointer calculated in the step of function calculation; obtaining for obtaining the differential calculated in the step of differential calculation; and data storage for storing the differential obtained in the step of obtaining in an another area in the dictionary medium.

Claim 12

A method of producing an electronic dictionary comprising: a dictionary medium; dictionary data composed of a plurality of dictionary data elements and stored in the dictionary medium; and an index file showing storage positions of all dictionary data elements and being stored in the dictionary medium, having the steps of: dictionary data storing for storing dictionary data in a first area in the dictionary medium; index file inputting for inputting an index file composed of pointers, each showing a storage position of a data element; first prediction function creating for creating a function, which predicts each pointer, from the last pointer input in the index file inputting step and the last index number; first prediction function calculating for calculating a prediction pointer by substituting an index number into the function created in the first prediction function creating step; first differential calculating for calculating a differential between a pointer input in the index file inputting step and its corresponding prediction pointer calculated in the first prediction function calculating step; differential range inputting for inputting upper and lower limits of a differential; differential determining for determining whether each differential calculated in the first differential calculating step is within the differential range input in the differential range inputting step; first data storing for storing the differential calculated in the first differential calculating step and the function created in the first prediction function creating step into a second area in the dictionary medium when the differential is within the differential range; block dividing for calculating an amount of change of increments of all pointers input in the index file inputting step and dividing the index file at a pointer whose amount of change of increment exceeds a given value, when the differential is not within the differential range; second prediction function creating for creating different functions for predicting each pointer in each block divided in the block dividing step; list creating for creating a list of the blocks divided in the block dividing step and the functions created in the second prediction function creating step; second prediction function calculating for calculating a prediction pointer by substituting an index number into the function create din the list creating step; second differential calculating for calculating a differential between a pointer input in the index file inputting step and its corresponding prediction pointer calculated in the second prediction function calculating step; and second data storing for storing the list created in the list creating step and the differential calculated in the second differential calculating step into the second area in the dictionary medium.

Claim 13

A method of producing an electronic dictionary comprising: a dictionary medium; dictionary data composed of a plurality of dictionary data elements and stored in the dictionary medium; and an index file showing storage positions of all dictionary data elements and being stored in the dictionary medium, having the steps of: dictionary data storing for storing dictionary data in a first area in the dictionary medium; index file inputting for inputting an index file composed of pointers, each showing a storage position of a data element; first prediction function creating for creating a function, which predicts each pointer, from the last pointer input in the index file inputting step and the last index number; first prediction function calculating for calculating a prediction pointer by substituting an index number into the function created in the first prediction function creating step; first differential calculating for calculating a differential between a pointer input in the index file inputting step and its corresponding prediction pointer calculated in the first prediction function calculating step; differential range inputting for inputting upper and lower limits of a differential; differential determining for determining whether each differential calculated in the first differential calculating step is within the differential range input in the differential range inputting step; first data storing for storing the differential calculated in the first differential calculating step and the function created in the first prediction function creating step into a second area in the dictionary medium when the differential is within the differential range; block dividing for calculating an amount of change of increments of all pointers input in the index file inputting step and dividing the index file at a pointer whose amount of change of increment exceeds a given value, when the differential is not within the differential range; second prediction function creating for creating different functions for predicting each pointer in each block divided in the block dividing step; list creating for creating a list of the blocks divided in the block dividing step and the functions created in the second prediction function creating step; second prediction function calculating for calculating a prediction pointer by substituting an index number into the function create din the list creating step; second differential calculating for calculating a differential between a pointer input in the index file inputting step and its corresponding prediction pointer calculated in the second prediction function calculating step; and second data storing for storing the list created in the list creating step and the differential calculated in the second differential calculating step into the second area in the dictionary medium.