6. An electronic device, comprising: one or more processors; memory; and one or more programs, wherein the one or more programs are stored in memory and configured to be executed by the one or more processors, the one or more programs including an operating system and instructions that when executed by the one or more processors cause the electronic device to: generate a decoding network for decoding speech input, the decoding network comprising a primary sub-network and one or more classification sub-networks, wherein: the primary sub-network includes a plurality of classification nodes, each classification node corresponding to a respective classification sub-network of the one or more classification sub-networks, wherein each respective classification sub-network is distinct from the primary sub-network; and each classification sub-network of the one or more classification sub-networks corresponds to a group of uncommon words; receive a speech input; and decode the speech input by: instantiating a token corresponding to the speech input in the primary sub-network; passing the token through the primary sub-network; when the token reaches a respective classification node of the plurality of classification nodes, transferring the token to the corresponding classification sub-network; passing the token through the corresponding classification sub-network; when the token reaches an accept node of the classification sub-network, returning a result of the token passing through the classification sub-network to the primary sub-network, wherein the result includes one or more words in the group of uncommon words corresponding to the classification sub-networks; output a string corresponding to the speech input that includes the one or more words.
6. An electronic device, comprising: one or more processors; memory; and one or more programs, wherein the one or more programs are stored in memory and configured to be executed by the one or more processors, the one or more programs including an operating system and instructions that when executed by the one or more processors cause the electronic device to: generate a decoding network for decoding speech input, the decoding network comprising a primary sub-network and one or more classification sub-networks, wherein: the primary sub-network includes a plurality of classification nodes, each classification node corresponding to a respective classification sub-network of the one or more classification sub-networks, wherein each respective classification sub-network is distinct from the primary sub-network; and each classification sub-network of the one or more classification sub-networks corresponds to a group of uncommon words; receive a speech input; and decode the speech input by: instantiating a token corresponding to the speech input in the primary sub-network; passing the token through the primary sub-network; when the token reaches a respective classification node of the plurality of classification nodes, transferring the token to the corresponding classification sub-network; passing the token through the corresponding classification sub-network; when the token reaches an accept node of the classification sub-network, returning a result of the token passing through the classification sub-network to the primary sub-network, wherein the result includes one or more words in the group of uncommon words corresponding to the classification sub-networks; output a string corresponding to the speech input that includes the one or more words. 7. The electronic device of claim 6 , wherein the returned result is a respective result in a plurality of possible token-passing results through the classification sub-network, the returned result having a higher rollback probability than any other result in the plurality of possible token passing results through the classification sub-network.