Congo River Compositional Intelligence

/** * RDF Parser for YAGO Turtle files * Parses Turtle (.ttl) format into subject-predicate-object triples */ export interface RDFTriple { subject: string; predicate: string; object: string; datatype?: string; language?: string; } export interface ParseOptions { skipComments?: boolean; skipPrefixes?: boolean; batchSize?: number; } export class RDFParser { private prefixes: Map<string, string> = new Map(); private currentBatchSize: number = 0; /** * Parse a Turtle file line by line * @param lines Lines from the Turtle file * @param options Parsing options * @returns Array of RDF triples */ parseLines(lines: string[], options: ParseOptions = {}): RDFTriple[] { const triples: RDFTriple[] = []; const { skipComments = true, skipPrefixes = false } = options; let currentSubject = ''; let currentPredicate = ''; for (let line of lines) { line = line.trim(); // Skip empty lines if (!line) continue; // Skip comments if (skipComments && line.startsWith('#')) continue; // Handle prefixes if (line.startsWith('@prefix') || line.startsWith('PREFIX')) { if (!skipPrefixes) { this.parsePrefix(line); } continue; } // Handle base declarations if (line.startsWith('@base') || line.startsWith('BASE')) { continue; } // Parse triple try { const triple = this.parseTripleLine(line, currentSubject, currentPredicate); if (triple) { triples.push(triple); // Update current subject/predicate for abbreviated syntax if (triple.subject) currentSubject = triple.subject; if (triple.predicate) currentPredicate = triple.predicate; } } catch (error) { console.warn(`Failed to parse line: ${line}`, error); } } return triples; } /** * Parse a single triple line */ private parseTripleLine( line: string, currentSubject: string, currentPredicate: string ): RDFTriple | null { // Remove trailing period line = line.replace(/\s*\.\s*$/, '').trim(); if (!line) return null; // Split by whitespace (simplified - doesn't handle all edge cases) const parts = this.splitTriple(line); if (parts.length < 3) { // Handle abbreviated syntax (comma or semicolon) if (line.startsWith(',') || line.startsWith(';')) { // TODO: Implement abbreviated syntax support return null; } return null; } const [subject, predicate, ...objectParts] = parts; const object = objectParts.join(' '); return { subject: this.expandPrefix(subject), predicate: this.expandPrefix(predicate), object: this.parseObject(object), }; } /** * Split triple handling quoted strings */ private splitTriple(line: string): string[] { const parts: string[] = []; let current = ''; let inQuotes = false; let quoteChar = ''; for (let i = 0; i < line.length; i++) { const char = line[i]; const prevChar = i > 0 ? line[i - 1] : ''; if ((char === '"' || char === "'") && prevChar !== '\\') { if (!inQuotes) { inQuotes = true; quoteChar = char; } else if (char === quoteChar) { inQuotes = false; quoteChar = ''; } current += char; } else if (char === ' ' && !inQuotes && current) { parts.push(current); current = ''; } else if (char !== ' ' || inQuotes) { current += char; } } if (current) { parts.push(current); } return parts; } /** * Parse object value (literal, URI, or blank node) */ private parseObject(object: string): string { // Remove surrounding quotes for literals if (object.startsWith('"') && object.includes('"')) { // Handle datatype or language tag const match = object.match(/"([^"]*)"(?:@([a-z]+)|\^\^(.+))?/); if (match) { return match[1]; // Return just the literal value } } // Expand prefixed URIs if (object.includes(':') && !object.startsWith('http')) { return this.expandPrefix(object); } // Remove angle brackets from URIs if (object.startsWith('<') && object.endsWith('>')) { return object.slice(1, -1); } return object; } /** * Parse prefix declaration */ private parsePrefix(line: string): void { // @prefix schema: <http://schema.org/> . const match = line.match(/@?prefix\s+([^:]+):\s*<([^>]+)>/i); if (match) { this.prefixes.set(match[1].trim(), match[2]); } } /** * Expand prefixed URI */ private expandPrefix(uri: string): string { if (uri.startsWith('<') && uri.endsWith('>')) { return uri.slice(1, -1); } const colonIndex = uri.indexOf(':'); if (colonIndex > 0) { const prefix = uri.substring(0, colonIndex); const localPart = uri.substring(colonIndex + 1); const baseUri = this.prefixes.get(prefix); if (baseUri) { return baseUri + localPart; } } return uri; } /** * Get all parsed prefixes */ getPrefixes(): Map<string, string> { return new Map(this.prefixes); } /** * Reset parser state */ reset(): void { this.prefixes.clear(); this.currentBatchSize = 0; } } /** * Utility function to parse RDF from string */ export function parseRDF(content: string, options?: ParseOptions): RDFTriple[] { const parser = new RDFParser(); const lines = content.split('\n'); return parser.parseLines(lines, options); }