ecclesia/dist/election/attribution/orderingFactory.cjs

Framework for political and electoral simulations

"use strict";
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var __getOwnPropNames = Object.getOwnPropertyNames;
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  return to;
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var __toESM = (mod, isNodeMode, target) => (target = mod != null ? __create(__getProtoOf(mod)) : {}, __copyProps(
  // If the importer is in node compatibility mode or this is not an ESM
  // file that has been converted to a CommonJS file using a Babel-
  // compatible transform (i.e. "__esModule" has not been set), then set
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  mod
));
var __toCommonJS = (mod) => __copyProps(__defProp({}, "__esModule", { value: true }), mod);

// src/election/attribution/orderingFactory.ts
var orderingFactory_exports = {};
__export(orderingFactory_exports, {
  bordaCount: () => bordaCount,
  condorcet: () => condorcet,
  instantRunoff: () => instantRunoff
});
module.exports = __toCommonJS(orderingFactory_exports);
var import_python4 = require("@gouvernathor/python");
var import_collections7 = require("@gouvernathor/python/collections");

// src/election/attribution/base.ts
var AttributionFailure = class extends Error {
};

// src/election/attribution/transform.ts
var import_collections = require("@gouvernathor/python/collections");

// src/election/attribution/proportionalBase.ts
var import_collections2 = require("@gouvernathor/python/collections");
function stationaryDivisorFunction(r) {
  return (k) => k + r;
}
function rankIndexFunctionFromDivisorFunction(divisorFunction) {
  return (t, a) => t / divisorFunction(a);
}

// src/election/attribution/majorityFactory.ts
var import_python = require("@gouvernathor/python");
var import_collections3 = require("@gouvernathor/python/collections");

// src/election/attribution/scoreFactory.ts
var import_python2 = require("@gouvernathor/python");
var import_collections4 = require("@gouvernathor/python/collections");
var import_statistics = require("@gouvernathor/python/statistics");

// src/election/ballots.ts
var Scores;
((Scores2) => {
  function get(key) {
    const value = this.get(key);
    if (value === void 0) {
      return Array(this.ngrades).fill(0);
    }
    return value;
  }
  function fromEntries(elements) {
    if (elements.length === 0) {
      throw new Error("Use the fromGrades method to create an empty Scores instance");
    }
    const ths = new Map(elements);
    ths.ngrades = elements[0][1].length;
    ths.get = get.bind(ths);
    return ths;
  }
  Scores2.fromEntries = fromEntries;
  function fromGrades(ngrades) {
    const ths = /* @__PURE__ */ new Map();
    ths.ngrades = ngrades;
    ths.get = get.bind(ths);
    return ths;
  }
  Scores2.fromGrades = fromGrades;
})(Scores || (Scores = {}));

// src/election/attribution/proportionalFactory.ts
var import_python3 = require("@gouvernathor/python");
var import_collections5 = require("@gouvernathor/python/collections");
var divisor1 = stationaryDivisorFunction(1);
var huntingtonHillBaseRankIndexFunction = rankIndexFunctionFromDivisorFunction((k) => Math.sqrt(k * (k + 1)));

// src/election/attribution/randomFactory.ts
var import_collections6 = require("@gouvernathor/python/collections");

// src/utils.ts
var import_rng = __toESM(require("@gouvernathor/rng"), 1);

// src/election/attribution/orderingFactory.ts
function instantRunoff({ nSeats }) {
  const attrib = (votes, rest = {}) => {
    const blacklisted = /* @__PURE__ */ new Set();
    const nParties = new Set(votes.flat()).size;
    for (let pn = 0; pn < nParties; pn++) {
      const firstPlaces = new import_collections7.Counter();
      for (const ballot of votes) {
        for (const party of ballot) {
          if (!blacklisted.has(party)) {
            firstPlaces.increment(party);
            break;
          }
        }
      }
      const total = firstPlaces.total;
      for (const [party, score] of firstPlaces) {
        if (score / total > 0.5) {
          return new import_collections7.Counter([[party, nSeats]]);
        }
      }
      blacklisted.add((0, import_python4.min)(firstPlaces.keys(), (p) => firstPlaces.get(p)));
    }
    throw new Error("Should not happen");
  };
  attrib.nSeats = nSeats;
  return attrib;
}
function bordaCount({ nSeats }) {
  const attrib = (votes, rest = {}) => {
    const scores = new import_collections7.Counter();
    for (const ballot of votes) {
      for (const [i, party] of (0, import_python4.enumerate)(ballot.slice().reverse(), 1)) {
        scores.increment(party, i);
      }
    }
    return new import_collections7.Counter([[(0, import_python4.max)(scores.keys(), (p) => scores.get(p)), nSeats]]);
  };
  attrib.nSeats = nSeats;
  return attrib;
}
function condorcet({ nSeats, contingency = null }) {
  const attrib = (votes, rest = {}) => {
    const counts = new import_collections7.DefaultMap(() => new import_collections7.Counter());
    const majority = votes.length / 2;
    for (const ballot of votes) {
      for (const [i, party1] of (0, import_python4.enumerate)(ballot)) {
        for (const party2 of ballot.slice(i + 1)) {
          counts.get(party1).increment(party2);
        }
      }
    }
    const win = new Set(counts.keys());
    for (const [party, partyCounter] of counts) {
      for (const value of partyCounter.pos.values()) {
        if (value > majority) {
          win.delete(party);
          break;
        }
      }
    }
    if (win.size !== 1) {
      if (win.size !== 0) {
        throw new Error("Bad attribution");
      }
      if (contingency === null) {
        throw new condorcet.Standoff("No Condorcet winner");
      }
      return contingency(votes, rest);
    }
    const [winner] = win;
    return new import_collections7.Counter([[winner, nSeats]]);
  };
  attrib.nSeats = nSeats;
  return attrib;
}
condorcet.Standoff = class CondorcetStandoff extends AttributionFailure {
};
// Annotate the CommonJS export names for ESM import in node:
0 && (module.exports = {
  bordaCount,
  condorcet,
  instantRunoff
});
//# sourceMappingURL=orderingFactory.cjs.map