error.d.ts

/**
 * This file is hand copied from peggy's peg.d.ts file so that end consumers
 * of the GLSL parser can use the error type without me having to fully publish
 * peggy as a dependency of this module.
 *
 * The primary exported type is GlslSyntaxError.
 */

/** Provides information pointing to a location within a source. */
export interface Location {
  /** Line in the parsed source (1-based). */
  line: number;
  /** Column in the parsed source (1-based). */
  column: number;
  /** Offset in the parsed source (0-based). */
  offset: number;
}

/** The `start` and `end` position's of an object within the source. */
export interface LocationRange {
  /** Any object that was supplied to the `parse()` call as the `grammarSource` option. */
  source: any;
  /** Position at the beginning of the expression. */
  start: Location;
  /** Position after the end of the expression. */
  end: Location;
}

/** Specific sequence of symbols is expected in the parsed source. */
interface LiteralExpectation {
  type: 'literal';
  /** Expected sequence of symbols. */
  text: string;
  /** If `true`, symbols of any case is expected. `text` in that case in lower case */
  ignoreCase: boolean;
}

/** One of the specified symbols is expected in the parse position. */
interface ClassExpectation {
  type: 'class';
  /** List of symbols and symbol ranges expected in the parse position. */
  parts: (string[] | string)[];
  /**
   * If `true`, meaning of `parts` is inverted: symbols that NOT expected in
   * the parse position.
   */
  inverted: boolean;
  /** If `true`, symbols of any case is expected. `text` in that case in lower case */
  ignoreCase: boolean;
}

/** Any symbol is expected in the parse position. */
interface AnyExpectation {
  type: 'any';
}

/** EOF is expected in the parse position. */
interface EndExpectation {
  type: 'end';
}

/**
 * Something other is expected in the parse position. That expectation is
 * generated by call of the `expected()` function in the parser code, as
 * well as rules with human-readable names.
 */
interface OtherExpectation {
  type: 'other';
  /**
   * Depending on the origin of this expectation, can be:
   * - text, supplied to the `expected()` function
   * - human-readable name of the rule
   */
  description: string;
}

type Expectation =
  | LiteralExpectation
  | ClassExpectation
  | AnyExpectation
  | EndExpectation
  | OtherExpectation;

/**
 * The entry that maps object in the `source` property of error locations
 * to the actual source text of a grammar. That entries is necessary for
 * formatting errors.
 */
export interface SourceText {
  /**
   * Identifier of a grammar that stored in the `location().source` property
   * of error and diagnostic messages.
   *
   * This one should be the same object that used in the `location().source`,
   * because their compared using `===`.
   */
  source: any;
  /** Source text of a grammar. */
  text: string;
}

export interface GlslSyntaxError extends Error {
  /** Location where error was originated. */
  location: LocationRange;
  /**
   * List of possible tokens in the parse position, or `null` if error was
   * created by the `error()` call.
   */
  expected: Expectation[] | null;
  /**
   * Character in the current parse position, or `null` if error was created
   * by the `error()` call.
   */
  found: string | null;

  /**
   * Format the error with associated sources.  The `location.source` should have
   * a `toString()` representation in order the result to look nice. If source
   * is `null` or `undefined`, it is skipped from the output
   *
   * Sample output:
   * ```
   * Error: Expected "!", "$", "&", "(", ".", "@", character class, comment, end of line, identifier, literal, or whitespace but "#" found.
   *  --> my grammar:3:9
   *   |
   * 3 | start = # 'a';
   *   |         ^
   * ```
   *
   * @param sources mapping from location source to source text
   *
   * @returns the formatted error
   */
  format(sources: SourceText[]): string;
  /**
   * Constructs the human-readable message from the machine representation.
   *
   * @param expected Array of expected items, generated by the parser
   * @param found Any text that will appear as found in the input instead of expected
   */
  // static buildMessage(expected: Expectation[], found: string): string;
  buildMessage(expected: Expectation[], found: string): string;
}