266 lines
8.8 KiB
JavaScript
266 lines
8.8 KiB
JavaScript
"use strict";
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/**
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* MIT License
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*
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* Copyright (c) 2021 Andrew Raffensperger
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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* This is a near carbon-copy of the original source (link below) with the
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* TypeScript typings added and a few tweaks to make it ES3-compatible.
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*
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* See: https://github.com/adraffy/ens-normalize.js
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*/
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.read_emoji_trie = exports.read_zero_terminated_array = exports.read_mapped_map = exports.read_member_array = exports.signed = exports.read_compressed_payload = exports.read_payload = exports.decode_arithmetic = void 0;
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// https://github.com/behnammodi/polyfill/blob/master/array.polyfill.js
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function flat(array, depth) {
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if (depth == null) {
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depth = 1;
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}
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var result = [];
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var forEach = result.forEach;
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var flatDeep = function (arr, depth) {
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forEach.call(arr, function (val) {
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if (depth > 0 && Array.isArray(val)) {
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flatDeep(val, depth - 1);
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}
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else {
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result.push(val);
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}
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});
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};
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flatDeep(array, depth);
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return result;
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}
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function fromEntries(array) {
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var result = {};
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for (var i = 0; i < array.length; i++) {
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var value = array[i];
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result[value[0]] = value[1];
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}
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return result;
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}
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function decode_arithmetic(bytes) {
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var pos = 0;
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function u16() { return (bytes[pos++] << 8) | bytes[pos++]; }
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// decode the frequency table
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var symbol_count = u16();
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var total = 1;
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var acc = [0, 1]; // first symbol has frequency 1
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for (var i = 1; i < symbol_count; i++) {
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acc.push(total += u16());
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}
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// skip the sized-payload that the last 3 symbols index into
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var skip = u16();
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var pos_payload = pos;
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pos += skip;
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var read_width = 0;
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var read_buffer = 0;
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function read_bit() {
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if (read_width == 0) {
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// this will read beyond end of buffer
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// but (undefined|0) => zero pad
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read_buffer = (read_buffer << 8) | bytes[pos++];
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read_width = 8;
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}
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return (read_buffer >> --read_width) & 1;
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}
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var N = 31;
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var FULL = Math.pow(2, N);
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var HALF = FULL >>> 1;
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var QRTR = HALF >> 1;
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var MASK = FULL - 1;
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// fill register
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var register = 0;
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for (var i = 0; i < N; i++)
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register = (register << 1) | read_bit();
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var symbols = [];
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var low = 0;
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var range = FULL; // treat like a float
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while (true) {
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var value = Math.floor((((register - low + 1) * total) - 1) / range);
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var start = 0;
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var end = symbol_count;
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while (end - start > 1) { // binary search
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var mid = (start + end) >>> 1;
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if (value < acc[mid]) {
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end = mid;
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}
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else {
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start = mid;
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}
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}
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if (start == 0)
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break; // first symbol is end mark
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symbols.push(start);
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var a = low + Math.floor(range * acc[start] / total);
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var b = low + Math.floor(range * acc[start + 1] / total) - 1;
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while (((a ^ b) & HALF) == 0) {
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register = (register << 1) & MASK | read_bit();
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a = (a << 1) & MASK;
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b = (b << 1) & MASK | 1;
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}
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while (a & ~b & QRTR) {
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register = (register & HALF) | ((register << 1) & (MASK >>> 1)) | read_bit();
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a = (a << 1) ^ HALF;
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b = ((b ^ HALF) << 1) | HALF | 1;
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}
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low = a;
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range = 1 + b - a;
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}
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var offset = symbol_count - 4;
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return symbols.map(function (x) {
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switch (x - offset) {
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case 3: return offset + 0x10100 + ((bytes[pos_payload++] << 16) | (bytes[pos_payload++] << 8) | bytes[pos_payload++]);
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case 2: return offset + 0x100 + ((bytes[pos_payload++] << 8) | bytes[pos_payload++]);
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case 1: return offset + bytes[pos_payload++];
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default: return x - 1;
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}
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});
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}
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exports.decode_arithmetic = decode_arithmetic;
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// returns an iterator which returns the next symbol
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function read_payload(v) {
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var pos = 0;
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return function () { return v[pos++]; };
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}
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exports.read_payload = read_payload;
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function read_compressed_payload(bytes) {
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return read_payload(decode_arithmetic(bytes));
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}
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exports.read_compressed_payload = read_compressed_payload;
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// eg. [0,1,2,3...] => [0,-1,1,-2,...]
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function signed(i) {
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return (i & 1) ? (~i >> 1) : (i >> 1);
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}
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exports.signed = signed;
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function read_counts(n, next) {
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var v = Array(n);
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for (var i = 0; i < n; i++)
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v[i] = 1 + next();
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return v;
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}
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function read_ascending(n, next) {
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var v = Array(n);
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for (var i = 0, x = -1; i < n; i++)
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v[i] = x += 1 + next();
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return v;
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}
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function read_deltas(n, next) {
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var v = Array(n);
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for (var i = 0, x = 0; i < n; i++)
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v[i] = x += signed(next());
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return v;
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}
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function read_member_array(next, lookup) {
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var v = read_ascending(next(), next);
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var n = next();
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var vX = read_ascending(n, next);
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var vN = read_counts(n, next);
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for (var i = 0; i < n; i++) {
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for (var j = 0; j < vN[i]; j++) {
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v.push(vX[i] + j);
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}
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}
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return lookup ? v.map(function (x) { return lookup[x]; }) : v;
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}
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exports.read_member_array = read_member_array;
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// returns array of
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// [x, ys] => single replacement rule
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// [x, ys, n, dx, dx] => linear map
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function read_mapped_map(next) {
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var ret = [];
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while (true) {
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var w = next();
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if (w == 0)
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break;
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ret.push(read_linear_table(w, next));
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}
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while (true) {
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var w = next() - 1;
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if (w < 0)
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break;
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ret.push(read_replacement_table(w, next));
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}
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return fromEntries(flat(ret));
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}
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exports.read_mapped_map = read_mapped_map;
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function read_zero_terminated_array(next) {
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var v = [];
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while (true) {
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var i = next();
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if (i == 0)
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break;
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v.push(i);
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}
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return v;
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}
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exports.read_zero_terminated_array = read_zero_terminated_array;
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function read_transposed(n, w, next) {
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var m = Array(n).fill(undefined).map(function () { return []; });
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for (var i = 0; i < w; i++) {
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read_deltas(n, next).forEach(function (x, j) { return m[j].push(x); });
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}
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return m;
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}
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function read_linear_table(w, next) {
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var dx = 1 + next();
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var dy = next();
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var vN = read_zero_terminated_array(next);
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var m = read_transposed(vN.length, 1 + w, next);
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return flat(m.map(function (v, i) {
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var x = v[0], ys = v.slice(1);
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//let [x, ...ys] = v;
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//return Array(vN[i]).fill().map((_, j) => {
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return Array(vN[i]).fill(undefined).map(function (_, j) {
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var j_dy = j * dy;
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return [x + j * dx, ys.map(function (y) { return y + j_dy; })];
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});
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}));
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}
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function read_replacement_table(w, next) {
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var n = 1 + next();
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var m = read_transposed(n, 1 + w, next);
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return m.map(function (v) { return [v[0], v.slice(1)]; });
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}
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function read_emoji_trie(next) {
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var sorted = read_member_array(next).sort(function (a, b) { return a - b; });
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return read();
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function read() {
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var branches = [];
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while (true) {
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var keys = read_member_array(next, sorted);
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if (keys.length == 0)
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break;
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branches.push({ set: new Set(keys), node: read() });
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}
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branches.sort(function (a, b) { return b.set.size - a.set.size; }); // sort by likelihood
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var temp = next();
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var valid = temp % 3;
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temp = (temp / 3) | 0;
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var fe0f = !!(temp & 1);
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temp >>= 1;
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var save = temp == 1;
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var check = temp == 2;
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return { branches: branches, valid: valid, fe0f: fe0f, save: save, check: check };
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}
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}
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exports.read_emoji_trie = read_emoji_trie;
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//# sourceMappingURL=decoder.js.map
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