Data extraction API improvements.

data-extraction/src/js/helpers/find.ts

@@ -42,3 +42,95 @@ export function find(predicate: (obj: unknown) => boolean): unknown {
 
 	return undefined;
 }
+
+export function findVar(
+	options: { nameSimilarTo?: string; ctor?: string },
+	predicate?: (value: any) => boolean
+): unknown | undefined {
+	if (!DataExtractorApiImpl.lastContext) {
+		throw new Error("No data extractor context!");
+	}
+
+	let bestValue = undefined;
+	let bestValueScore = undefined; // minimized
+
+	for (const [name, value] of Object.entries(
+		DataExtractorApiImpl.lastContext.variablesInScope
+	)) {
+		const v = value();
+		if (options.ctor !== undefined) {
+			if (
+				typeof v !== "object" ||
+				!v ||
+				v.constructor.name !== options.ctor
+			) {
+				continue;
+			}
+		}
+		if (predicate) {
+			if (!predicate(v)) {
+				continue;
+			}
+		}
+		let score = 0;
+		if (options.nameSimilarTo !== undefined) {
+			score += similarityScore(name, options.nameSimilarTo);
+		} else {
+			return v;
+		}
+		if (bestValueScore === undefined || score < bestValueScore) {
+			bestValue = v;
+			bestValueScore = score;
+		}
+	}
+
+	return bestValue;
+}
+
+function similarityScore(a: string, b: string): number {
+	const distance = levenshteinDistance(a, b);
+
+	const aSorted = a.split("").sort().join("");
+	const bSorted = b.split("").sort().join("");
+	const distance2 = levenshteinDistance(aSorted, bSorted);
+
+	return distance * 10 + distance2;
+}
+
+function levenshteinDistance(a: string, b: string): number {
+	if (a.length === 0) return b.length;
+	if (b.length === 0) return a.length;
+
+	const matrix = [];
+
+	// increment along the first column of each row
+	let i;
+	for (i = 0; i <= b.length; i++) {
+		matrix[i] = [i];
+	}
+
+	// increment each column in the first row
+	let j;
+	for (j = 0; j <= a.length; j++) {
+		matrix[0][j] = j;
+	}
+
+	// Fill in the rest of the matrix
+	for (i = 1; i <= b.length; i++) {
+		for (j = 1; j <= a.length; j++) {
+			if (b.charAt(i - 1) == a.charAt(j - 1)) {
+				matrix[i][j] = matrix[i - 1][j - 1];
+			} else {
+				matrix[i][j] = Math.min(
+					matrix[i - 1][j - 1] + 1, // substitution
+					Math.min(
+						matrix[i][j - 1] + 1, // insertion
+						matrix[i - 1][j] + 1
+					)
+				); // deletion
+			}
+		}
+	}
+
+	return matrix[b.length][a.length];
+}