| 摘要 |
A compactly stored word list that includes a directed graph data structure is used for word to number (W/N) and number to word (N/W) mapping. Each word accepted by the data structure is mapped to a unique corresponding number within a dense set of numbers ranging from zero to one less than the total number of acceptable words. Some common suffixes are collapsed into shared branches, which is possible because the numbers are not stored within the word list. In addition, some branches of the data structure can be skipped during mapping because of information associated with branch points. That information permits the mapping scan to continue with a next branch or with an alternative branch. That information also indicates the number of suffix endings in the next branch; this number is used to keep a count of the word endings during word to number mapping; it is also used both to determine whether to continue with the next branch and also to reduce the number being mapped during number to word mapping. The branching information includes a full length pointer to the next branch or a shorter length pointer index to a table in which the pointer is stored. In either case, the number of suffix endings in the next branch is annexed to the pointer. The pointers and pointer indexes are assigned iteratively, the shortest pointer indexes first, then longer pointer indexes, and finally the full length pointers. In each case, a pointer or pointer index is assigned only if beneficial, and the assignment of pointers and pointer indexes is cleared and redone if a better assignment can be made.
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