2. The computer-implemented method of claim 1 , wherein configuring the buffer comprises: configuring the buffer as a first-in-first-out buffer to hold a number of tokens equal to a number of tokens in the selected ordered sequence of query tokens.
2. The computer-implemented method of claim 1 , wherein configuring the buffer comprises: configuring the buffer as a first-in-first-out buffer to hold a number of tokens equal to a number of tokens in the selected ordered sequence of query tokens. 3. The computer-implemented method of claim 2 , wherein the comparing comprises: sequentially inputting tokens from the selected ordered sequence of document tokens into the first-in-first-out buffer; and comparing, upon each said sequential input of a token, the selected ordered sequence of query tokens to the first-in-first-out buffer.