Initial

resources/app/node_modules/peggy/lib/compiler/session.js

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+"use strict";
+
+const GrammarError = require("../grammar-error");
+
+class Defaults {
+  constructor(options) {
+    options = typeof options !== "undefined" ? options : {};
+
+    if (typeof options.error === "function") { this.error = options.error; }
+    if (typeof options.warning === "function") { this.warning = options.warning; }
+    if (typeof options.info === "function") { this.info = options.info; }
+  }
+
+  // eslint-disable-next-line class-methods-use-this -- Abstract
+  error() {
+    // Intentionally empty placeholder
+  }
+
+  // eslint-disable-next-line class-methods-use-this -- Abstract
+  warning() {
+    // Intentionally empty placeholder
+  }
+
+  // eslint-disable-next-line class-methods-use-this -- Abstract
+  info() {
+    // Intentionally empty placeholder
+  }
+}
+
+class Session {
+  constructor(options) {
+    this._callbacks = new Defaults(options);
+    this._firstError = null;
+    this.errors = 0;
+    /** @type {import("../peg").Problem[]} */
+    this.problems = [];
+    /** @type {import("../peg").Stage} */
+    this.stage = null;
+  }
+
+  error(...args) {
+    ++this.errors;
+    // In order to preserve backward compatibility we cannot change `GrammarError`
+    // constructor, nor throw another class of error:
+    // - if we change `GrammarError` constructor, this will break plugins that
+    //   throws `GrammarError`
+    // - if we throw another Error class, this will break parser clients that
+    //   catches GrammarError
+    //
+    // So we use a compromise: we throw an `GrammarError` with all found problems
+    // in the `problems` property, but the thrown error itself is the first
+    // registered error.
+    //
+    // Thus when the old client catches the error it can find all properties on
+    // the Grammar error that it want. On the other hand the new client can
+    // inspect the `problems` property to get all problems.
+    if (this._firstError === null) {
+      this._firstError = new GrammarError(...args);
+      this._firstError.stage = this.stage;
+      this._firstError.problems = this.problems;
+    }
+
+    this.problems.push(["error", ...args]);
+    this._callbacks.error(this.stage, ...args);
+  }
+
+  warning(...args) {
+    this.problems.push(["warning", ...args]);
+    this._callbacks.warning(this.stage, ...args);
+  }
+
+  info(...args) {
+    this.problems.push(["info", ...args]);
+    this._callbacks.info(this.stage, ...args);
+  }
+
+  checkErrors() {
+    if (this.errors !== 0) {
+      throw this._firstError;
+    }
+  }
+}
+
+module.exports = Session;