jspeech

Node.js module for creating JSpeech Grammar Formats, JSGF.

Note: jspeech is just a api for creating JSGF. The format specification can be read here: https://www.w3.org/TR/jsgf.

Usage

import jspeech from 'jspeech';
 
const grammar = jspeech('cockney');
 
grammar.rule('stairs', 'apples and pears');
 
grammar.stringify(); // #JSGF V1.0 utf-8 en; grammar cockney; <stairs> = apples and pears;

Creating Grammar

To create a speech grammar simply call the factory function from jspeech with the name of the grammar and any header options.

const grammar = jspeech('name', {
    version: 'V1.0',
    lang: 'en',
    encoding: 'utf-8',
});

Adding Rules

Add rules to the grammar object via the .rule() method. A rule must have a name and an valid JSGF rule token(s).

grammar.rule('hello', 'hello'); // <name> = hello'
grammar.rule('greeting', '(<hello> | hey | sup)'); // <greeting> = (<hello> | hey | sup);
grammar.rule('greet', '<greeting> buddy'); // <greet> = <greeting> buddy;

Public Rules

Only public rules are exported to a recogniser. To make a rule public use the .public API on the grammar object.

grammar.public.rule('friend', 'everyone'); // public <friend> = everyone;

Sequences

To ensure that a rule keeps a sequence of tokens together use the .word() method to wrap the tokens in quotes.

grammar.word('nyc', 'New York City'); // <nyc> = "New York City";

Alternatives, Weights and Groups

Alternatives allow variations of different rules and/or rule tokens. This allows for a more complex grammar format. Use the .alt() method to create different rule alternatives.

grammar.alt('cities', ['London', 'Sydney', 'Tokyo']); // <cities> = London | Sydney | Tokyo;
grammar.alt('colours', [
    ['red', 0.5],
    ['green', 0.3],
    ['blue', 0.8],
]); // <colours> = /0.5/ red | /0.3/ green | /0.8/ blue;

Alternatives can also accept options which allow token groups.

grammar.alt('answer', ['yes', 'no', 'maybe'], {
    group: true,    // creates group
    optional: true, // wrap in [] instead of ()
}); // <answer> = [yes | no | maybe];

Generating Format

Once a grammar has been created and all rules are defined. It can be used to generate the JSGF for use with a SpeechGrammarList.

import window from 'global/window';
import grammar from './grammar';
 
const SpeechGrammarList = window.SpeechGrammarList || window.webkitSpeechGrammarList;
 
const list = new SpeechGrammarList();
list.addFromString(grammar.stringify());

API

#jspeech(<name>, [header])

• name String Grammar name.
• header Object Grammar header information.

Returns a grammar object.

Grammar Object

grammar.rule(<name>, [token, [opts]])

grammar.public.rule(<name>, [token, [opts]])

• name String Name of token.
• token String|Array Token or array of alternative tokens.
• opts Object Rule options.

Returns Void.

grammar.word(<name>, [word, [opts]])

grammar.public.word(<name>, [word, [opts]])

• name String Name of word token.
• word String Word token.
• opts Object Rule options.

Returns Void.

grammar.alt(<name>, [alternatives, [opts]])

grammar.public.alt(<name>, [alternatives, [opts]])

• name String Name of word token.
• alternatives Array Array of alternative tokens.
• opts Object Rule options.

Returns Void.

grammar.tokens()

Returns an Array of rule definitions.

grammar.stringify()

Returns a String of the generated JSGF.

License

MIT

Copyright (c) 2017 Christopher Turner