ExpReal

ExpReal ('Expressive Realizer') is a multilingual surface realizer designed for generating text in interactive narratives. It allows authors to write templates that will be transformed into text. Under the hood, it uses SimpleNLG-NL for inflection and picking pronouns. SimpleNLG-NL is based on SimpleNLG. ExpReal is capable of realization in English, French and Dutch.

(It is still being developed further.)

Installation

Either clone the project or add it as a Maven dependency through Jitpack. For the latter option, add the following repository to your POM file:

<repositories>
    <repository>
        <id>jitpack.io</id>
        <url>https://jitpack.io</url>
    </repository>
</repositories>

Then add ExpReal itself:

<dependencies>
    <dependency>
        <groupId>com.github.rfdj</groupId>
        <artifactId>ExpReal</artifactId>
        <version>c894e361e0</version>
    </dependency>
</dependencies>

Note: As long as there is no real release, use the first 10 characters of a commit hash to get that 'version'. Or use master-SNAPSHOT to always get the latest.

You can also easily pick a different version by going to Jitpack and clicking the Get it button next to the preferred commit. That will build the project (if not already done so) and give you the commit hash (and example maven code) for it.

Usage

To use it, add this project as a dependency and initialize an instance of ExpressiveActionRealizer, passing it a filename (situated in the resources) and a language. The file contains your templates as described below. For the language, the options are ERLanguage.ENGLISH, ERLanguage.FRENCH and ERLanguage.DUTCH. Each instance of ExpressiveActionRealizer can only have one language. Create multiple instance for multiple languages.

ExpressiveActionRealizer(String fileName, ERLanguage language)

for example:

ExpressiveActionRealizer ear = new ExpressiveActionRealizer("TemplatesFile.csv", ERLanguage.ENGLISH);

The most important method of the realizer is ear.getTexts(). That method is responsible for the actual realization and returns the resulting text. As parameters, it requires a predicate and a context. See below for a full example.

Full example

Make sure you've built a template file according to the specifications in the next section.

ExpressiveActionRealizer ear = new ExpressiveActionRealizer("TemplatesFile.csv", ERLanguage.ENGLISH);

/* Construction of a predicate */
Vector<ERArgument> arguments = new Vector<>();
arguments.add(new ERArgument("task", "brush"));
arguments.add(new ERArgument("argument", "teeth"));
ERPredicate myPredicate = new ERPredicate("giveMeSomething", arguments);

/* Construction of a context */
ERPerson julia = new ERPerson("julia", ERGender.FEMININE);
ERPerson frank = new ERPerson("frank", ERGender.MASCULINE);

ERContext context = new ERContext(julia, frank);
context.setSpeaker(julia);
context.setListener(frank);

/* Get results */
Vector<String> result = ear.getTexts(myPredicate, context);

for (String utterance : result) {
    System.out.println(utterance);
}

The result should be Julia asking Frank to brush his teeth: 'Please, brush your teeth!' For more examples, have a look in the src/test/java folder.

Authoring templates

All templates are stored in a single file to make it easier to translate and coordinate. It's a simple CSV file with five columns (separated by semicolons):

Predicate name	Conditions	English	French	Dutch

Example:

Predicate name	Conditions	English	French	Dutch
giveMeSomething		Please, $task!	S'il te plait $task!	$task, alsjeblieft!
brush		brush your %argument	brosse-toi %argument	poets je %argument
teeth		teeth	les dents	tanden
julia		Julia	Julia	Julia
frank		Frank	François	Frank

Template syntax

Each template can consist of plain 'canned' text or include different types of variables to make it more dynamic. There are two types of variable to be used in the text of the template itself:

1. context variables: starting with %, such as names of characters or items
2. predicate variables: starting with $ for subclauses, tasks etc.

A third type of non-text items in templates are so-called 'grammatical blocks'. These indicate the grammatical role of the word contained within it. That helps with inflection and referring expression generation.

Note: Grammatical blocks can contain variables, too!

Example:

{subject: %julia} {verb: like} eating fries.

This can result in Julia likes eating fries. or I like eating fries. or even You like eating fries. based on the context.

Conditions

The second column in the template file is reserved for conditions. The template with the largest number of met conditions is picked for the realisation.

ExpReal has the following condition types:

• $contextVar = someString with $contextVar being defined as an ERArgument in the ERPredicate.
• $player = %john
• $player.aggression >= 0.5 gives you access to the properties of an ERPerson set by myErPerson.addProperty("arbitraryName", 0.0f) with the value being a Flaot. Allowed operators: <, >, <=, >=.
• @overridingFlag gives this template the highest priority to be chosen.

You can add multiple conditions to one template. Separate them with a comma.

For examples, check out the unit tests and the accompanying test templates.

License

ExpReal is released under the Apache 2.0 license. See the LICENSE file for details.