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'use strict';
// --------------------------------------------------------------------// Imports// --------------------------------------------------------------------
const UnicodeCategories = require('../third_party/UnicodeCategories');const common = require('./common');
// --------------------------------------------------------------------// Private stuff// --------------------------------------------------------------------
// General stuff
class PExpr {  constructor() {    if (this.constructor === PExpr) {      throw new Error("PExpr cannot be instantiated -- it's abstract");    }  }
  // Set the `source` property to the interval containing the source for this expression.  withSource(interval) {    if (interval) {      this.source = interval.trimmed();    }    return this;  }}
// Any
const any = Object.create(PExpr.prototype);
// End
const end = Object.create(PExpr.prototype);
// Terminals
class Terminal extends PExpr {  constructor(obj) {    super();    this.obj = obj;  }}
// Ranges
class Range extends PExpr {  constructor(from, to) {    super();    this.from = from;    this.to = to;    // If either `from` or `to` is made up of multiple code units, then    // the range should consume a full code point, not a single code unit.    this.matchCodePoint = from.length > 1 || to.length > 1;  }}
// Parameters
class Param extends PExpr {  constructor(index) {    super();    this.index = index;  }}
// Alternation
class Alt extends PExpr {  constructor(terms) {    super();    this.terms = terms;  }}
// Extend is an implementation detail of rule extension
class Extend extends Alt {  constructor(superGrammar, name, body) {    const origBody = superGrammar.rules[name].body;    super([body, origBody]);
    this.superGrammar = superGrammar;    this.name = name;    this.body = body;  }}
// Splice is an implementation detail of rule overriding with the `...` operator.class Splice extends Alt {  constructor(superGrammar, ruleName, beforeTerms, afterTerms) {    const origBody = superGrammar.rules[ruleName].body;    super([...beforeTerms, origBody, ...afterTerms]);
    this.superGrammar = superGrammar;    this.ruleName = ruleName;    this.expansionPos = beforeTerms.length;  }}
// Sequences
class Seq extends PExpr {  constructor(factors) {    super();    this.factors = factors;  }}
// Iterators and optionals
class Iter extends PExpr {  constructor(expr) {    super();    this.expr = expr;  }}
class Star extends Iter {}class Plus extends Iter {}class Opt extends Iter {}
Star.prototype.operator = '*';Plus.prototype.operator = '+';Opt.prototype.operator = '?';
Star.prototype.minNumMatches = 0;Plus.prototype.minNumMatches = 1;Opt.prototype.minNumMatches = 0;
Star.prototype.maxNumMatches = Number.POSITIVE_INFINITY;Plus.prototype.maxNumMatches = Number.POSITIVE_INFINITY;Opt.prototype.maxNumMatches = 1;
// Predicates
class Not extends PExpr {  constructor(expr) {    super();    this.expr = expr;  }}
class Lookahead extends PExpr {  constructor(expr) {    super();    this.expr = expr;  }}
// "Lexification"
class Lex extends PExpr {  constructor(expr) {    super();    this.expr = expr;  }}
// Rule application
class Apply extends PExpr {  constructor(ruleName, args = []) {    super();    this.ruleName = ruleName;    this.args = args;  }
  isSyntactic() {    return common.isSyntactic(this.ruleName);  }
  // This method just caches the result of `this.toString()` in a non-enumerable property.  toMemoKey() {    if (!this._memoKey) {      Object.defineProperty(this, '_memoKey', {value: this.toString()});    }    return this._memoKey;  }}
// Unicode character
class UnicodeChar extends PExpr {  constructor(category) {    super();    this.category = category;    this.pattern = UnicodeCategories[category];  }}
// --------------------------------------------------------------------// Exports// --------------------------------------------------------------------
exports.PExpr = PExpr;exports.any = any;exports.end = end;exports.Terminal = Terminal;exports.Range = Range;exports.Param = Param;exports.Alt = Alt;exports.Extend = Extend;exports.Splice = Splice;exports.Seq = Seq;exports.Iter = Iter;exports.Star = Star;exports.Plus = Plus;exports.Opt = Opt;exports.Not = Not;exports.Lookahead = Lookahead;exports.Lex = Lex;exports.Apply = Apply;exports.UnicodeChar = UnicodeChar;