Slot type resolution process

A computer-implemented method comprising:

• receiving a request to analyze a written or spoken utterance;
• tokenizing the received utterance;
• generating one or more labels corresponding to a substring of the tokenized received utterance, each of the labels including one or more slot types, by:
• for each path of a grammar-based finite state transducer (FST) data structure that includes instructions, traversing the path as far as possible for matches from a previous breakpoint, while maintaining i) locations of branching points and snapshots at those branching points and ii) an indication of which paths have been traversed, wherein each of the instructions causes a performance of a defined, non-token matching action when the instruction is encountered during the traversing, and wherein one of the instructions is an instruction to call another FST;
• calling the another FST and traversing a path of the another FST;
• and
• recording a result of each path traversal as a generated label;
• resolving the one or more generated labels into machine-readable values;
• and
• outputting a result of the resolving to an entity as dictated by the request.

A system comprising:

• a bot implemented by a first one or more electronic devices;
• and
• a natural language understanding (NLU) service implemented by a second one or more electronic devices, the NLU service including instructions that upon execution are to cause:
• receiving a request to analyze a written or spoken utterance;
• tokenizing the received utterance;
• generating one or more labels corresponding to a substring of the tokenized received utterance, each of the labels including one or more slot types, by:
• for each path of a grammar-based finite state transducer (FST) data structure that includes instructions, traversing the path as far as possible for matches from a previous breakpoint, while maintaining i) locations of branching points and snapshots at those branching points and ii) an indication of which paths have been traversed, wherein each of the instructions causes a performance of a defined, non-token matching action when the instruction is encountered during the traversing, and wherein one of the instructions is an instruction to call another FST;
• calling the another FST and traversing a path of the another FST;
• and
• recording a result of each path traversal as a generated label;
• resolving the one or more generated labels into machine-readable values;
• and
• outputting a result of the resolving to an entity as dictated by the request.