1. A computer-implemented method of automatically generating regular expressions for relaxed matching of text patterns, comprising: a computing system receiving a first rule specifying a first operator that replaces a search phrase with a replacement regular expression; said computing system receiving one or more other rules; said computing system receiving an input phrase expressed in a natural language, the input phrase including the search phrase; said computing system determining that said received input phrase is a plain text pattern rather than a regular expression; prior to using an output regular expression to search documents for the search phrase and one or more variations of the search phrase, said computing system automatically generating the output regular expression by performing the steps of: based on said input phrase determined to be the plain text pattern rather than the regular expression, said computing system automatically tokenizing said plain text pattern; said computing system automatically generating a first list of tokens based on the tokenized plain text pattern, the first list of tokens including the search phrase; based on the first operator specified by the first rule, subsequent to said automatically generating the first list of tokens, subsequent to said receiving the first rule, and subsequent to said receiving said one or more other rules, said computing system determining an offset in the first list of tokens, the offset indicating where the search phrase occurs in the first list of tokens; based on the first operator specified by the first rule, said computing system copying one or more tokens that are before the offset in the first list of tokens to a second list of tokens; based on the first operator specified by the first rule, and subsequent to said copying the one or more tokens that are before the offset to the second list of tokens, said computing system appending a token of the replacement regular expression to the second list of tokens; based on the first operator specified by the first rule, and subsequent to said appending the token of the replacement regular expression to the second list of tokens, said computing system appending one or more tokens that are after the search phrase in the first list of tokens to the second list of tokens; and based on the received first rule and the received one or more other rules, based on the token of the replacement regular expression appended to the second list of tokens, and subsequent to said appending the one or more tokens that are after the search phrase to the second list of tokens, said computing system converting the second list of tokens into an output regular expression so that the output regular expression includes the replacement regular expression, the output regular expression being a representation describing a set of strings including said plain text pattern and one or more variations of said plain text pattern without said output regular expression listing said plain text pattern and each variation of said one or more variations of said plain text pattern, said one or more variations of said plain text pattern having a same meaning as said plain text pattern and including the one or more variations of the search phrase; and subsequent to said converting the second list of tokens to the output regular expression and subsequent to said automatically generating the output regular expression, said computing system using the output regular expression to search the documents for the search phrase and the one or more variations of the search phrase.
3. The method of claim 1 , further comprising: said computing system receiving a set of rules consisting of the first rule, a second rule, a third rule, and a fourth rule, wherein said receiving the set of rules consists of said receiving the first rule and said receiving the one or more other rules, wherein the second rule specifies a second operator that detects a colon specified by said second rule and splits a token of said first list of tokens into two tokens based on said colon detected in the token of the first list of tokens, wherein the third rule specifies a third operator that replaces the colon with a second replacement regular expression, and wherein the fourth rule specifies a fourth operator that replaces whitespace with a third replacement regular expression; prior to said automatically generating the first list of tokens, said computing system identifying whitespace in the plain text pattern, wherein said automatically generating the first list of tokens includes replacing the identified whitespace with a delimiter token in the first list of tokens: prior to said converting the second list of tokens, and based on the fourth operator specified by the fourth rule, said computing system copying said delimiter token to the second list of tokens, wherein said converting the second list of tokens into the output regular expression includes replacing the delimiter token with a whitespace token specified in the fourth rule; prior to said converting the second list of tokens and based on the second operator specified by the second rule, said computing system detecting the colon in a second token in the first list of tokens, and in response to said detecting the colon, said computing system splitting the second token into third and fourth tokens with the colon in between the third and fourth tokens; and based on the third operator specified by the third rule, subsequent to said splitting the second token into the third and fourth tokens with the colon in between the third and fourth tokens, and prior to said converting the second list of tokens, said computing system appending a token of the second replacement regular expression to the second list of tokens, wherein said converting the second list of tokens includes, based on the token of the second replacement regular expression appended to the second list of tokens, said computing system converting the second list of tokens into the output regular expression so that the output regular expression further includes the second replacement regular expression.