Semantic D1 MCP

/** * 🎯 SEMANTIC INTENT: Index represents database index metadata * * WHY: Indexes are semantic performance optimization markers * - name: Observable identifier * - tableName: Table being indexed * - columns: Indexed columns (order matters for composite indexes) * - isUnique: Semantic uniqueness constraint * - isPrimaryKey: Indicates if this is a primary key index * * OBSERVABLE PROPERTIES: Directly observable from sqlite_master * SEMANTIC ANCHORING: Indexes indicate intentional query optimization * IMMUTABILITY: Frozen to preserve schema semantics */ export class Index { public readonly name: string; public readonly tableName: string; public readonly columns: readonly string[]; public readonly isUnique: boolean; public readonly isPrimaryKey: boolean; constructor( name: string, tableName: string, columns: string[], isUnique: boolean = false, isPrimaryKey: boolean = false, ) { if (!name || name.trim().length === 0) { throw new Error('Index name cannot be empty'); } if (!tableName || tableName.trim().length === 0) { throw new Error('Table name cannot be empty'); } if (!columns || columns.length === 0) { throw new Error('Index must have at least one column'); } if (columns.some((col) => !col || col.trim().length === 0)) { throw new Error('Index column names cannot be empty'); } this.name = name.trim(); this.tableName = tableName.trim(); this.columns = Object.freeze([...columns.map((col) => col.trim())]); this.isUnique = isUnique; this.isPrimaryKey = isPrimaryKey; Object.freeze(this); } /** * Check if this is a composite index (multiple columns) * * Semantic: Composite indexes optimize multi-column queries */ isComposite(): boolean { return this.columns.length > 1; } /** * Check if index covers a specific column * * Observable: Column coverage is directly observable */ coversColumn(columnName: string): boolean { return this.columns.includes(columnName); } /** * Check if index is the first column (most selective) * * Semantic: First column in composite index can be used alone */ hasColumnAsPrefix(columnName: string): boolean { return this.columns[0] === columnName; } /** * Get index column count */ getColumnCount(): number { return this.columns.length; } }