antlr-ng/dist/src/tool/LeftRecursiveRule.js

Next generation ANTLR Tool

var __defProp = Object.defineProperty;
var __name = (target, value) => __defProp(target, "name", { value, configurable: true });
import { Rule } from "./Rule.js";
class LeftRecursiveRule extends Rule {
  static {
    __name(this, "LeftRecursiveRule");
  }
  /** Did we delete any labels on direct left-recur refs? Points at ID of ^(= ID el) */
  leftRecursiveRuleRefLabels = new Array();
  recPrimaryAlts;
  recOpAlts;
  originalAST;
  constructor(g, name, ast) {
    super(g, name, ast, 1);
    this.originalAST = ast;
  }
  hasAltSpecificContexts() {
    return super.hasAltSpecificContexts() || this.getAltLabels() !== null;
  }
  getOriginalNumberOfAlts() {
    return this.recPrimaryAlts.length + this.recOpAlts.size;
  }
  getOriginalAST() {
    return this.originalAST;
  }
  getUnlabeledAltASTs() {
    const alts = new Array();
    for (const altInfo of this.recPrimaryAlts) {
      if (altInfo.altLabel === void 0) {
        alts.push(altInfo.originalAltAST);
      }
    }
    for (let i = 0; i < this.recOpAlts.size; i++) {
      const altInfo = this.recOpAlts.getElement(i);
      if (altInfo.altLabel === void 0) {
        alts.push(altInfo.originalAltAST);
      }
    }
    if (alts.length === 0) {
      return null;
    }
    return alts;
  }
  /**
   * @returns an array that maps predicted alt from primary decision to original alt of rule. For following rule,
   * returns [0, 2, 4]
   *
   * ```antlr
   * e : e '*' e
   *   | INT
   *   | e '+' e
   *   | ID
   *   ;
   * ```
   *
   * That maps predicted alt 1 to original alt 2 and predicted 2 to alt 4.
   */
  getPrimaryAlts() {
    const alts = [0];
    for (const altInfo of this.recPrimaryAlts) {
      alts.push(altInfo.altNum);
    }
    return alts;
  }
  /**
   * @returns an array that maps predicted alt from recursive op decision to original alt of rule. For following rule,
   * returns [0, 1, 3]
   *
   * ```antlr
   * e : e '*' e
   *   | INT
   *   | e '+' e
   *   | ID
   *   ;
   * ```
   * That maps predicted alt 1 to original alt 1 and predicted 2 to alt 3.
   */
  getRecursiveOpAlts() {
    const alts = [0];
    for (const [_, altInfo] of this.recOpAlts) {
      alts.push(altInfo.altNum);
    }
    return alts;
  }
  /** @returns labels from those alts we deleted for left-recursive rules. */
  getAltLabels() {
    const labels = /* @__PURE__ */ new Map();
    const normalAltLabels = super.getAltLabels();
    if (normalAltLabels !== null) {
      normalAltLabels.forEach((value, key) => {
        labels.set(key, value);
      });
    }
    for (const altInfo of this.recPrimaryAlts) {
      if (altInfo.altLabel !== void 0) {
        let pairs = labels.get(altInfo.altLabel);
        if (!pairs) {
          pairs = [];
          labels.set(altInfo.altLabel, pairs);
        }
        pairs.push([altInfo.altNum, altInfo.originalAltAST]);
      }
    }
    for (let i = 0; i < this.recOpAlts.size; i++) {
      const altInfo = this.recOpAlts.getElement(i);
      if (altInfo.altLabel !== void 0) {
        let pairs = labels.get(altInfo.altLabel);
        if (!pairs) {
          pairs = [];
          labels.set(altInfo.altLabel, pairs);
        }
        pairs.push([altInfo.altNum, altInfo.originalAltAST]);
      }
    }
    if (labels.size === 0) {
      return null;
    }
    return labels;
  }
}
export {
  LeftRecursiveRule
};