Rule-based number formatter

摘要

A number translation engine is based on a textual description of the procedure for spelling out a number in any of a variety of languages. The number translation engine comprises an output alphabetical representation formatter which, in turn, comprises a formatting engine and rule set. Each rule within a rule set includes a base output alphabetical representation and an indication to the formatting engine, either implicitly or explicitly, of a range of numerical values for which the rule applies. The formatting engine obtains a base output alphabetical representation from an appropriate rule within a rule set and builds up an output alphabetical representation, adding output alphabetical representation s from other rules within the rule set, as necessary. Additionally, where appropriate, a rule indicates where "additional" output alphabetical representation s may be placed in relation to the base, or root, output alphabetical representation in order to construct a complete output alphabetical representation. The formatting engine may operate in concert with various rule sets in order to effect various numerical-to-alphabetical translations. The translation engine may also comprise a parser which is connected to receive an alphabetical input string and to associate the alphabetical input string with a numerical output string having the same numerical value. The parser comprises a parsing engine and rule set and illustratively, the parsing engine may employ the same rule sets as employed by the formatting engine. After receiving an alphabetical representation representation of a number, the parser proceeds to match alphabetical characters in the string with alphabetical characters within the appropriate rule's base output alphabetical representation, and assigning the appropriate multiple of the rule's base value to the numerical output string. The parser proceeds in this manner, from rule to rule, until the input alphabetical character string is exhausted.