question

I've just started playing with Alexa and making examples for anything non-trivial is already becoming cumbersome. So, using the JSGF gem I wrote awhile back, I've whipped up a bit of code that converts grammars into examples. Hopefully it'll be useful for someone else too. Be careful though; large grammars tend to produce even larger example sets. To use this, install the 'jsgf' gem, and then dump the following into a ruby file (I put it in a Rakefile). It's still a bit rough, and the JSGF gem itself still needs a lot of work, but it's a start. Feel free point out bugs, etc. [code]require 'jsgf' module JSGF class Grammar # Convert a {Grammar} into a set of sample utterances for Alexa # @option slots [Array] The rule names that should be used as slot names # @return [Array ] An array of the example strings def to_examples(slots:[]) raise StandardError, "The grammar must have at least one root rule" unless roots raise StandardError, "The grammar must contain at least one public rule" if roots.empty? roots.flat_map {|name, rule| expand_atom(rule, ["#{name}Intent"], slots:slots) } end # Expand an {Atom} into an array of strings # @return [Array] def expand_atom(atom, prefix=[], slots:[], slot_name:nil) case atom when JSGF::Alternation atom.map {|a| expand_atom(a, prefix, slots:slots, slot_name:slot_name) } when JSGF::Atom if prefix.first.is_a?(Array) prefix.map {|pref| expand_atom(atom, pref, slots:slots, slot_name:slot_name) } else atom_name = atom.to_s atom_name = "{#{atom_name}|#{slot_name}}" if slot_name && !atom_name.empty? atom_name = nil if atom_name.empty? [[*prefix, atom_name].compact.join(' ')] end when JSGF::Rule, Array atom.reduce(prefix) {|memo, a| expand_atom(a, memo, slots:slots, slot_name:slot_name)} when Hash reference_name = atom[:name] slot_name = slots.include?(reference_name) ? reference_name : nil expand_atom(rules[atom[:name]], prefix, slots:slots, slot_name:slot_name) else raise "Unknown atom #{atom}" end end end end # Example usage. Replace this with your actual grammar. grammar = JSGF.grammar 'ColorExpert' do rule MyColorIs: 'my favorite color is :Color' rule Color: %w{green red blue orange gold silver yellow black white} end File.write('utterances.txt', grammar.to_examples(slots:['Color'])) [/code]