antlr4ng/dist/atn/ATNSimulator.js

Alternative JavaScript/TypeScript runtime for ANTLR4

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  }
  return to;
};
var __toCommonJS = (mod) => __copyProps(__defProp({}, "__esModule", { value: true }), mod);

// src/atn/ATNSimulator.ts
var ATNSimulator_exports = {};
__export(ATNSimulator_exports, {
  ATNSimulator: () => ATNSimulator
});
module.exports = __toCommonJS(ATNSimulator_exports);

// src/utils/helpers.ts
var valueToString = /* @__PURE__ */ __name((v) => {
  return v === null ? "null" : v;
}, "valueToString");
var arrayToString = /* @__PURE__ */ __name((value) => {
  return Array.isArray(value) ? "[" + value.map(valueToString).join(", ") + "]" : "null";
}, "arrayToString");
var equalArrays = /* @__PURE__ */ __name((a, b) => {
  if (a === b) {
    return true;
  }
  if (a.length !== b.length) {
    return false;
  }
  for (let i = 0; i < a.length; i++) {
    const left = a[i];
    const right = b[i];
    if (left === right) {
      continue;
    }
    if (!left || !left.equals(right)) {
      return false;
    }
  }
  return true;
}, "equalArrays");
var equalNumberArrays = /* @__PURE__ */ __name((a, b) => {
  if (a === b) {
    return true;
  }
  if (a.length !== b.length) {
    return false;
  }
  for (let i = 0; i < a.length; i++) {
    if (a[i] !== b[i]) {
      return false;
    }
  }
  return true;
}, "equalNumberArrays");

// src/dfa/DFAState.ts
var DFAState = class _DFAState {
  static {
    __name(this, "DFAState");
  }
  stateNumber = -1;
  configs;
  /**
   * `edges[symbol]` points to target of symbol. Shift up by 1 so (-1) {@link Token.EOF} maps to `edges[0]`.
   */
  edges = [];
  isAcceptState = false;
  /**
   * If accept state, what ttype do we match or alt do we predict? This is set to {@link ATN.INVALID_ALT_NUMBER}
   * when {@link predicates} `!= null` or {@link requiresFullContext}.
   */
  prediction = -1;
  lexerActionExecutor = null;
  /**
   * Indicates that this state was created during SLL prediction that discovered a conflict between the configurations
   * in the state. Future {@link ParserATNSimulator.execATN} invocations immediately jumped doing
   * full context prediction if this field is true.
   */
  requiresFullContext = false;
  /**
   * During SLL parsing, this is a list of predicates associated with the ATN configurations of the DFA state.
   * When we have predicates, {@link requiresFullContext} is `false` since full context prediction evaluates
   * predicates on-the-fly. If this is not null, then {@link prediction} is `ATN.INVALID_ALT_NUMBER`.
   *
   * We only use these for non-{@link #requiresFullContext} but conflicting states. That
   * means we know from the context (it's $ or we don't dip into outer
   * context) that it's an ambiguity not a conflict.
   *
   * This list is computed by {@link ParserATNSimulator#predicateDFAState}.
   */
  predicates = null;
  constructor(configs) {
    if (configs) {
      this.configs = configs;
    }
  }
  static fromState(stateNumber) {
    const result = new _DFAState();
    result.stateNumber = stateNumber;
    return result;
  }
  static fromConfigs(configs) {
    return new _DFAState(configs);
  }
  static hashCode(state) {
    return state.configs.hashCode();
  }
  /**
   * Two {@link DFAState} instances are equal if their ATN configuration sets
   * are the same. This method is used to see if a state already exists.
   *
   * Because the number of alternatives and number of ATN configurations are
   * finite, there is a finite number of DFA states that can be processed.
   * This is necessary to show that the algorithm terminates.
   *
   * Cannot test the DFA state numbers here because in
   * {@link ParserATNSimulator#addDFAState} we need to know if any other state
   * exists that has this exact set of ATN configurations. The
   * {@link #stateNumber} is irrelevant.
   *
   * @param a The first {@link DFAState}.
   * @param b The second {@link DFAState}.
   *
   * @returns `true` if the two states are equal, otherwise `false`.
   */
  static equals(a, b) {
    return a.configs.equals(b.configs);
  }
  /**
   * @returns the set of all alts mentioned by all ATN configurations in this DFA state.
   */
  getAltSet() {
    const alts = /* @__PURE__ */ new Set();
    for (const config of this.configs) {
      alts.add(config.alt);
    }
    if (alts.size === 0) {
      return null;
    }
    return alts;
  }
  toString() {
    let buf = "";
    buf += this.stateNumber;
    buf += ":";
    buf += this.configs ? this.configs.toString() : "";
    if (this.isAcceptState) {
      buf += "=>";
      if (this.predicates) {
        buf += arrayToString(this.predicates);
      } else {
        buf += this.prediction;
      }
    }
    return buf.toString();
  }
};

// src/misc/ObjectEqualityComparator.ts
var ObjectEqualityComparator = class _ObjectEqualityComparator {
  static {
    __name(this, "ObjectEqualityComparator");
  }
  static instance = new _ObjectEqualityComparator();
  hashCode(obj) {
    if (obj == null) {
      return 0;
    }
    return obj.hashCode();
  }
  equals(a, b) {
    if (a == null) {
      return b == null;
    }
    return a.equals(b);
  }
};

// src/misc/DefaultEqualityComparator.ts
var DefaultEqualityComparator = class _DefaultEqualityComparator {
  static {
    __name(this, "DefaultEqualityComparator");
  }
  static instance = new _DefaultEqualityComparator();
  hashCode(obj) {
    if (obj == null) {
      return 0;
    }
    return ObjectEqualityComparator.instance.hashCode(obj);
  }
  equals(a, b) {
    if (a == null) {
      return b == null;
    }
    if (typeof a === "string" || typeof a === "number") {
      return a === b;
    }
    return ObjectEqualityComparator.instance.equals(a, b);
  }
};

// src/utils/MurmurHash.ts
var c1 = 3432918353;
var c2 = 461845907;
var r1 = 15;
var r2 = 13;
var m = 5;
var n = 3864292196;
var MurmurHash = class _MurmurHash {
  static {
    __name(this, "MurmurHash");
  }
  static defaultSeed = 701;
  constructor() {
  }
  /**
   * Initialize the hash using the specified {@code seed}.
   *
   * @param seed the seed
   *
   * @returns the intermediate hash value
   */
  static initialize(seed = _MurmurHash.defaultSeed) {
    return seed;
  }
  static updateFromComparable(hash, value) {
    return this.update(hash, value?.hashCode() ?? 0);
  }
  /**
   * Update the intermediate hash value for the next input {@code value}.
   *
   * @param hash The intermediate hash value.
   * @param value the value to add to the current hash.
   *
   * @returns the updated intermediate hash value
   */
  static update(hash, value) {
    value = Math.imul(value, c1);
    value = value << r1 | value >>> 32 - r1;
    value = Math.imul(value, c2);
    hash = hash ^ value;
    hash = hash << r2 | hash >>> 32 - r2;
    hash = Math.imul(hash, m) + n;
    return hash;
  }
  /**
   * Apply the final computation steps to the intermediate value {@code hash}
   * to form the final result of the MurmurHash 3 hash function.
   *
   * @param hash The intermediate hash value.
   * @param entryCount The number of values added to the hash.
   *
   * @returns the final hash result
   */
  static finish(hash, entryCount) {
    hash ^= entryCount * 4;
    hash ^= hash >>> 16;
    hash = Math.imul(hash, 2246822507);
    hash ^= hash >>> 13;
    hash = Math.imul(hash, 3266489909);
    hash ^= hash >>> 16;
    return hash;
  }
  /**
   * An all-in-one convenience method to compute a hash for a single value.
   *
   * @param value The value to hash.
   * @param seed The seed for the hash value.
   *
   * @returns The computed hash.
   */
  static hashCode(value, seed) {
    return _MurmurHash.finish(_MurmurHash.update(seed ?? _MurmurHash.defaultSeed, value), 1);
  }
};

// src/misc/HashSet.ts
var HashSet = class _HashSet {
  static {
    __name(this, "HashSet");
  }
  static defaultLoadFactor = 0.75;
  static initialCapacity = 16;
  // must be power of 2
  comparator;
  buckets;
  threshold;
  /** How many elements in set */
  itemCount = 0;
  constructor(comparatorOrSet, initialCapacity = _HashSet.initialCapacity) {
    if (comparatorOrSet instanceof _HashSet) {
      this.comparator = comparatorOrSet.comparator;
      this.buckets = comparatorOrSet.buckets.slice(0);
      for (let i = 0; i < this.buckets.length; i++) {
        const bucket = this.buckets[i];
        if (bucket) {
          this.buckets[i] = bucket.slice(0);
        }
      }
      this.itemCount = comparatorOrSet.itemCount;
      this.threshold = comparatorOrSet.threshold;
    } else {
      this.comparator = comparatorOrSet ?? DefaultEqualityComparator.instance;
      this.buckets = this.createBuckets(initialCapacity);
      this.threshold = Math.floor(_HashSet.initialCapacity * _HashSet.defaultLoadFactor);
    }
  }
  /**
   * Add `o` to set if not there; return existing value if already
   * there. This method performs the same operation as {@link #add} aside from
   * the return value.
   *
   * @param o the object to add to the set.
   *
   * @returns An existing element that equals to `o` if already in set, otherwise `o`.
   */
  getOrAdd(o) {
    if (this.itemCount > this.threshold) {
      this.expand();
    }
    const b = this.getBucket(o);
    let bucket = this.buckets[b];
    if (!bucket) {
      bucket = [o];
      this.buckets[b] = bucket;
      ++this.itemCount;
      return o;
    }
    for (const existing of bucket) {
      if (this.comparator.equals(existing, o)) {
        return existing;
      }
    }
    bucket.push(o);
    ++this.itemCount;
    return o;
  }
  get(o) {
    if (o == null) {
      return o;
    }
    const b = this.getBucket(o);
    const bucket = this.buckets[b];
    if (!bucket) {
      return void 0;
    }
    for (const e of bucket) {
      if (this.comparator.equals(e, o)) {
        return e;
      }
    }
    return void 0;
  }
  /**
   * Removes the specified element from this set if it is present.
   *
   * @param o object to be removed from this set, if present.
   *
   * @returns `true` if the set contained the specified element.
   */
  remove(o) {
    if (o == null) {
      return false;
    }
    const b = this.getBucket(o);
    const bucket = this.buckets[b];
    if (!bucket) {
      return false;
    }
    for (let i = 0; i < bucket.length; i++) {
      const existing = bucket[i];
      if (this.comparator.equals(existing, o)) {
        bucket.splice(i, 1);
        --this.itemCount;
        return true;
      }
    }
    return false;
  }
  hashCode() {
    let hash = MurmurHash.initialize();
    for (const bucket of this.buckets) {
      if (bucket == null) {
        continue;
      }
      for (const o of bucket) {
        if (o == null) {
          break;
        }
        hash = MurmurHash.update(hash, this.comparator.hashCode(o));
      }
    }
    hash = MurmurHash.finish(hash, this.size);
    return hash;
  }
  equals(o) {
    if (o === this) {
      return true;
    }
    if (!(o instanceof _HashSet)) {
      return false;
    }
    if (o.size !== this.size) {
      return false;
    }
    return this.containsAll(o);
  }
  add(t) {
    const existing = this.getOrAdd(t);
    return existing === t;
  }
  contains(o) {
    return this.containsFast(o);
  }
  containsFast(obj) {
    if (obj == null) {
      return false;
    }
    return this.get(obj) !== void 0;
  }
  *[Symbol.iterator]() {
    yield* this.toArray();
  }
  toArray() {
    const a = new Array(this.size);
    let i = 0;
    for (const bucket of this.buckets) {
      if (bucket == null) {
        continue;
      }
      for (const o of bucket) {
        if (o == null) {
          break;
        }
        a[i++] = o;
      }
    }
    return a;
  }
  containsAll(collection) {
    if (collection instanceof _HashSet) {
      for (const bucket of collection.buckets) {
        if (bucket == null) {
          continue;
        }
        for (const o of bucket) {
          if (o == null) {
            break;
          }
          if (!this.containsFast(o)) {
            return false;
          }
        }
      }
    } else {
      for (const o of collection) {
        if (!this.containsFast(o)) {
          return false;
        }
      }
    }
    return true;
  }
  addAll(c) {
    let changed = false;
    for (const o of c) {
      const existing = this.getOrAdd(o);
      if (existing !== o) {
        changed = true;
      }
    }
    return changed;
  }
  clear() {
    this.buckets = this.createBuckets(_HashSet.initialCapacity);
    this.itemCount = 0;
    this.threshold = Math.floor(_HashSet.initialCapacity * _HashSet.defaultLoadFactor);
  }
  toString() {
    if (this.size === 0) {
      return "{}";
    }
    let buf = "{";
    let first = true;
    for (const bucket of this.buckets) {
      if (bucket == null) {
        continue;
      }
      for (const o of bucket) {
        if (o == null) {
          break;
        }
        if (first) {
          first = false;
        } else {
          buf += ", ";
        }
        buf += o.toString();
      }
    }
    buf += "}";
    return buf;
  }
  toTableString() {
    let buf = "";
    for (const bucket of this.buckets) {
      if (bucket == null) {
        buf += "null\n";
        continue;
      }
      buf += "[";
      let first = true;
      for (const o of bucket) {
        if (first) {
          first = false;
        } else {
          buf += " ";
        }
        if (o == null) {
          buf += "_";
        } else {
          buf += o.toString();
        }
      }
      buf += "]\n";
    }
    return buf;
  }
  getBucket(o) {
    const hash = this.comparator.hashCode(o);
    const b = hash & this.buckets.length - 1;
    return b;
  }
  expand() {
    const old = this.buckets;
    const newCapacity = this.buckets.length * 2;
    const newTable = this.createBuckets(newCapacity);
    this.buckets = newTable;
    this.threshold = Math.floor(newCapacity * _HashSet.defaultLoadFactor);
    for (const bucket of old) {
      if (!bucket) {
        continue;
      }
      for (const o of bucket) {
        const b = this.getBucket(o);
        let newBucket = this.buckets[b];
        if (!newBucket) {
          newBucket = [];
          this.buckets[b] = newBucket;
        }
        newBucket.push(o);
      }
    }
  }
  get size() {
    return this.itemCount;
  }
  get isEmpty() {
    return this.itemCount === 0;
  }
  /**
   * Return an array of `T[]` with length `capacity`.
   *
   * @param capacity the length of the array to return
   * @returns the newly constructed array
   */
  createBuckets(capacity) {
    return new Array(capacity);
  }
};

// src/misc/MapKeyEqualityOperator.ts
var MapKeyEqualityComparator = class {
  static {
    __name(this, "MapKeyEqualityComparator");
  }
  keyComparator;
  constructor(keyComparator) {
    this.keyComparator = keyComparator;
  }
  hashCode(obj) {
    return this.keyComparator.hashCode(obj.key);
  }
  equals(a, b) {
    return this.keyComparator.equals(a.key, b.key);
  }
};

// src/misc/HashMap.ts
var HashMap = class _HashMap {
  static {
    __name(this, "HashMap");
  }
  backingStore;
  constructor(keyComparer) {
    if (keyComparer instanceof _HashMap) {
      this.backingStore = new HashSet(keyComparer.backingStore);
    } else {
      keyComparer = keyComparer ?? DefaultEqualityComparator.instance;
      this.backingStore = new HashSet(new MapKeyEqualityComparator(keyComparer));
    }
  }
  clear() {
    this.backingStore.clear();
  }
  containsKey(key) {
    return this.backingStore.contains({ key });
  }
  get(key) {
    const bucket = this.backingStore.get({ key });
    if (!bucket) {
      return void 0;
    }
    return bucket.value;
  }
  get isEmpty() {
    return this.backingStore.isEmpty;
  }
  /**
   * Sets the value for a key in the map. If the key is not present in the map, it is added.
   * If the key is present, the value is updated and the old value is returned.
   *
   * @param key The key to set.
   * @param value The value to set.
   *
   * @returns The old value for the key, if present.
   */
  set(key, value) {
    const element = this.backingStore.get({ key, value });
    let result;
    if (!element) {
      this.backingStore.add({ key, value });
    } else {
      result = element.value;
      element.value = value;
    }
    return result;
  }
  /**
   * Sets the value for a key in the map if the key is not already present. Otherwise the value is not changed and
   * the old value is returned.
   *
   * @param key The key to set.
   * @param value The value to set.
   *
   * @returns The current value for the key, if present.
   */
  setIfAbsent(key, value) {
    const element = this.backingStore.get({ key, value });
    let result;
    if (!element) {
      this.backingStore.add({ key, value });
    } else {
      result = element.value;
    }
    return result;
  }
  keys() {
    return this.backingStore.toArray().map((bucket) => {
      return bucket.key;
    });
  }
  values() {
    return this.backingStore.toArray().map((bucket) => {
      return bucket.value;
    });
  }
  get size() {
    return this.backingStore.size;
  }
  hashCode() {
    return this.backingStore.hashCode();
  }
  equals(o) {
    return this.backingStore.equals(o.backingStore);
  }
};

// src/atn/PredictionContext.ts
var PredictionContext = class _PredictionContext {
  static {
    __name(this, "PredictionContext");
  }
  /**
   * Represents `$` in an array in full context mode, when `$`
   * doesn't mean wildcard: `$ + x = [$,x]`. Here,
   * `$` = {@link EMPTY_RETURN_STATE}.
   */
  static EMPTY_RETURN_STATE = 2147483647;
  static traceATNSimulator = false;
  cachedHashCode;
  constructor(cachedHashCode) {
    this.cachedHashCode = cachedHashCode;
  }
  static calculateEmptyHashCode() {
    let hash = MurmurHash.initialize(31);
    hash = MurmurHash.finish(hash, 0);
    return hash;
  }
  static calculateHashCodeSingle(parent, returnState) {
    let hash = MurmurHash.initialize(31);
    hash = MurmurHash.updateFromComparable(hash, parent);
    hash = MurmurHash.update(hash, returnState);
    hash = MurmurHash.finish(hash, 2);
    return hash;
  }
  static calculateHashCodeList(parents, returnStates) {
    let hash = MurmurHash.initialize(31);
    for (const parent of parents) {
      hash = MurmurHash.updateFromComparable(hash, parent);
    }
    for (const returnState of returnStates) {
      hash = MurmurHash.update(hash, returnState);
    }
    hash = MurmurHash.finish(hash, 2 * parents.length);
    return hash;
  }
  isEmpty() {
    return false;
  }
  hasEmptyPath() {
    return this.getReturnState(this.length - 1) === _PredictionContext.EMPTY_RETURN_STATE;
  }
  hashCode() {
    return this.cachedHashCode;
  }
  toString(_recog) {
    return "";
  }
};

// src/atn/SingletonPredictionContext.ts
var SingletonPredictionContext = class _SingletonPredictionContext extends PredictionContext {
  static {
    __name(this, "SingletonPredictionContext");
  }
  parent;
  returnState;
  constructor(parent, returnState) {
    super(
      parent ? PredictionContext.calculateHashCodeSingle(parent, returnState) : PredictionContext.calculateEmptyHashCode()
    );
    this.parent = parent ?? null;
    this.returnState = returnState;
  }
  getParent(_index) {
    return this.parent;
  }
  getReturnState(_index) {
    return this.returnState;
  }
  equals(other) {
    if (this === other) {
      return true;
    }
    if (!(other instanceof _SingletonPredictionContext)) {
      return false;
    }
    if (this.hashCode() !== other.hashCode()) {
      return false;
    }
    if (this.returnState !== other.returnState) {
      return false;
    }
    if (this.parent == null) {
      return other.parent == null;
    }
    return this.parent.equals(other.parent);
  }
  toString() {
    const up = this.parent === null ? "" : this.parent.toString();
    if (up.length === 0) {
      if (this.returnState === PredictionContext.EMPTY_RETURN_STATE) {
        return "$";
      }
      return "" + this.returnState;
    } else {
      return "" + this.returnState + " " + up;
    }
  }
  get length() {
    return 1;
  }
};

// src/atn/EmptyPredictionContext.ts
var EmptyPredictionContext = class _EmptyPredictionContext extends SingletonPredictionContext {
  static {
    __name(this, "EmptyPredictionContext");
  }
  /**
   * Represents `$` in local context prediction, which means wildcard.
   * `*+x = *`.
   */
  static instance = new _EmptyPredictionContext();
  constructor() {
    super(void 0, PredictionContext.EMPTY_RETURN_STATE);
  }
  isEmpty() {
    return true;
  }
  getParent() {
    return null;
  }
  getReturnState() {
    return this.returnState;
  }
  equals(other) {
    return this === other;
  }
  toString() {
    return "$";
  }
};

// src/atn/helpers.ts
var createSingletonPredictionContext = /* @__PURE__ */ __name((parent, returnState) => {
  if (returnState === PredictionContext.EMPTY_RETURN_STATE && parent === null) {
    return EmptyPredictionContext.instance;
  } else {
    return new SingletonPredictionContext(parent, returnState);
  }
}, "createSingletonPredictionContext");

// src/atn/ArrayPredictionContext.ts
var ArrayPredictionContext = class _ArrayPredictionContext extends PredictionContext {
  static {
    __name(this, "ArrayPredictionContext");
  }
  parents = [];
  returnStates = [];
  constructor(parents, returnStates) {
    super(PredictionContext.calculateHashCodeList(parents, returnStates));
    this.parents = parents;
    this.returnStates = returnStates;
    return this;
  }
  isEmpty() {
    return this.returnStates[0] === PredictionContext.EMPTY_RETURN_STATE;
  }
  get length() {
    return this.returnStates.length;
  }
  getParent(index) {
    return this.parents[index];
  }
  getReturnState(index) {
    return this.returnStates[index];
  }
  equals(other) {
    if (this === other) {
      return true;
    }
    if (!(other instanceof _ArrayPredictionContext) || this.hashCode() !== other.hashCode()) {
      return false;
    }
    return equalNumberArrays(this.returnStates, other.returnStates) && equalArrays(this.parents, other.parents);
  }
  toString() {
    if (this.isEmpty()) {
      return "[]";
    }
    const entries = [];
    for (let i = 0; i < this.returnStates.length; i++) {
      if (this.returnStates[i] === PredictionContext.EMPTY_RETURN_STATE) {
        entries.push("$");
        continue;
      }
      entries.push(this.returnStates[i].toString());
      if (this.parents[i]) {
        entries.push(this.parents[i].toString());
      } else {
        entries.push("null");
      }
    }
    return `[${entries.join(", ")}]`;
  }
};

// src/atn/PredictionContextUtils.ts
var getCachedPredictionContext = /* @__PURE__ */ __name((context, contextCache, visited) => {
  if (context.isEmpty()) {
    return context;
  }
  let existing = visited.get(context);
  if (existing) {
    return existing;
  }
  existing = contextCache.get(context);
  if (existing) {
    visited.set(context, existing);
    return existing;
  }
  let changed = false;
  let parents = [];
  for (let i = 0; i < parents.length; i++) {
    const parent = getCachedPredictionContext(context.getParent(i), contextCache, visited);
    if (changed || parent !== context.getParent(i)) {
      if (!changed) {
        parents = [];
        for (let j = 0; j < context.length; j++) {
          parents[j] = context.getParent(j);
        }
        changed = true;
      }
      parents[i] = parent;
    }
  }
  if (!changed) {
    contextCache.add(context);
    visited.set(context, context);
    return context;
  }
  let updated;
  if (parents.length === 0) {
    updated = EmptyPredictionContext.instance;
  } else if (parents.length === 1) {
    updated = createSingletonPredictionContext(parents[0] ?? void 0, context.getReturnState(0));
  } else {
    updated = new ArrayPredictionContext(parents, context.returnStates);
  }
  contextCache.add(updated);
  visited.set(updated, updated);
  visited.set(context, updated);
  return updated;
}, "getCachedPredictionContext");

// src/atn/ATNSimulator.ts
var ATNSimulator = class {
  static {
    __name(this, "ATNSimulator");
  }
  /** Must distinguish between missing edge and edge we know leads nowhere */
  static ERROR = DFAState.fromState(2147483647);
  atn;
  /**
   * The context cache maps all PredictionContext objects that are ==
   * to a single cached copy. This cache is shared across all contexts
   * in all ATNConfigs in all DFA states.  We rebuild each ATNConfigSet
   * to use only cached nodes/graphs in addDFAState(). We don't want to
   * fill this during closure() since there are lots of contexts that
   * pop up but are not used ever again. It also greatly slows down closure().
   *
   * This cache makes a huge difference in memory and a little bit in speed.
   * For the Java grammar on java.*, it dropped the memory requirements
   * at the end from 25M to 16M. We don't store any of the full context
   * graphs in the DFA because they are limited to local context only,
   * but apparently there's a lot of repetition there as well. We optimize
   * the config contexts before storing the config set in the DFA states
   * by literally rebuilding them with cached subgraphs only.
   *
   * I tried a cache for use during closure operations, that was
   * whacked after each adaptivePredict(). It cost a little bit
   * more time I think and doesn't save on the overall footprint
   * so it's not worth the complexity.
   */
  sharedContextCache;
  constructor(atn, sharedContextCache) {
    this.atn = atn;
    this.sharedContextCache = sharedContextCache;
    return this;
  }
  getCachedContext(context) {
    if (!this.sharedContextCache) {
      return context;
    }
    const visited = new HashMap(ObjectEqualityComparator.instance);
    return getCachedPredictionContext(context, this.sharedContextCache, visited);
  }
};