Command line utility to produce a symbol table from an input text corpus. Creates a symbol entry for every type in the corpus, as well as for <epsilon>
(index 0) and an out-of-vocabulary symbol (last in the symbol table). Command line options --epsilon_symbol
permit the specification of the labels wanted for those special symbols.
ngramsymbols [--options] [in.txt [out.txt]]
--epsilon_symbol: type = string, default = <epsilon>
--OOV_symbol: type = string, default = <unk>
$ ngramsymbols <earnest.txt >earnest.syms