wordmap/dist/structures/Alignment.js

Multi-Lingual Word Alignment Prediction

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
/**
 * Represents two individual n-grams that have been matched from two texts.
 * e.g. from a primary text and secondary text.
 */
class Alignment {
    /**
     * Instantiates a new alignment
     * @param {Ngram} sourceNgram - an n-gram from the source text
     * @param {Ngram} targetNgram - an n-gram from the secondary text
     */
    constructor(sourceNgram, targetNgram) {
        this.sourceNgram = sourceNgram;
        this.targetNgram = targetNgram;
    }
    /**
     * Returns the n-gram from the source text.
     * @deprecated Consider using {@link sourceNgram} instead since getters have a performance hit.
     * @return {Ngram}
     */
    get source() {
        return this.sourceNgram;
    }
    /**
     * Returns the n-gram from the target text
     * @deprecated Consider using {@link targetNgram} instead since getters have a performance hit.
     * @return {Ngram}
     */
    get target() {
        return this.targetNgram;
    }
    /**
     * Returns the alignment key.
     * TODO: would a regular function be faster?
     * @return {string}
     */
    get key() {
        this.cacheKeys();
        return this.cachedKey;
    }
    /**
     * Returns the alignment lemma-based key
     */
    get lemmaKey() {
        this.cacheKeys();
        return this.cachedLemmaKey;
    }
    /**
     * Outputs the alignment to json
     * @param verbose - print full metadata
     * @return {object}
     */
    toJSON(verbose = false) {
        return {
            sourceNgram: this.sourceNgram.toJSON(verbose),
            targetNgram: this.targetNgram.toJSON(verbose)
        };
    }
    /**
     * Caches the keys if they have not already been generated
     */
    cacheKeys() {
        if (this.cachedKey === undefined) {
            this.cachedKey = `${this.sourceNgram.key}->${this.targetNgram.key}`;
            // TRICKY: the alignment supports lemma fallback if either language has lemma
            const sourceHasLemma = this.sourceNgram.lemmaKey !== undefined;
            const targetHasLemma = this.targetNgram.lemmaKey !== undefined;
            if (sourceHasLemma || targetHasLemma) {
                const sourceLemma = sourceHasLemma ?
                    this.sourceNgram.lemmaKey :
                    this.sourceNgram.key;
                const targetLemma = targetHasLemma ?
                    this.targetNgram.lemmaKey :
                    this.targetNgram.key;
                this.cachedLemmaKey = `${sourceLemma}->${targetLemma}`;
            }
        }
    }
}
exports.default = Alignment;