IonSubstituteSymbolTable.ts

/*!
 * Copyright 2012 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * or in the "license" file accompanying this file. This file is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */

import { SharedSymbolTable } from "./IonSharedSymbolTable";

/**
 * A special case of shared symbol table whose entries are all undefined. Used in certain cases
 * when an import cannot be satisfied by the current catalog.
 * @see https://amazon-ion.github.io/ion-docs/symbols.html#imports
 */
export class SubstituteSymbolTable extends SharedSymbolTable {
  constructor(length: number) {
    if (length < 0) {
      throw new Error(
        "Cannot instantiate a SubstituteSymbolTable with a negative length. (" +
          length +
          ")"
      );
    }
    super("_substitute", -1, []);
    this._numberOfSymbols = length;
  }

  getSymbolText(symbolId: number): string | undefined {
    if (symbolId < 0) {
      throw new Error(
        `Index ${symbolId} is out of bounds for the SharedSymbolTable name=${this.name}, version=${this.version}`
      );
    }
    return undefined;
  }

  getSymbolId(text: string): number | undefined {
    return undefined;
  }
}