Files
mivodev.github.io/node_modules/entities/dist/commonjs/internal/encode-shared.js

94 lines
3.6 KiB
JavaScript

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.parseEncodeTrie = parseEncodeTrie;
/**
* Parse a compact encode trie string into a Map structure used for encoding.
*
* Format per entry (ascending code points using delta encoding):
* <diffBase36>[&name;][{<children>}] -- diff omitted when 0
* Where diff = currentKey - previousKey - 1 (first entry stores absolute key).
* `&name;` is the entity value (already wrapped); a following `{` denotes children.
*/
function parseEncodeTrie(serialized) {
const top = new Map();
const totalLength = serialized.length;
let cursor = 0;
let lastTopKey = -1;
function readDiff() {
const start = cursor;
while (cursor < totalLength) {
const char = serialized.charAt(cursor);
if ((char < "0" || char > "9") && (char < "a" || char > "z")) {
break;
}
cursor++;
}
if (cursor === start)
return 0;
return Number.parseInt(serialized.slice(start, cursor), 36);
}
function readEntity() {
if (serialized[cursor] !== "&") {
throw new Error(`Child entry missing value near index ${cursor}`);
}
// Cursor currently points at '&'
const start = cursor;
const end = serialized.indexOf(";", cursor + 1);
if (end === -1) {
throw new Error(`Unterminated entity starting at index ${start}`);
}
cursor = end + 1; // Move past ';'
return serialized.slice(start, cursor); // Includes & ... ;
}
while (cursor < totalLength) {
const keyDiff = readDiff();
const key = lastTopKey === -1 ? keyDiff : lastTopKey + keyDiff + 1;
let value;
if (serialized[cursor] === "&")
value = readEntity();
if (serialized[cursor] === "{") {
cursor++; // Skip '{'
// Parse first child
let diff = readDiff();
let childKey = diff; // First key (lastChildKey = -1)
const firstValue = readEntity();
if (serialized[cursor] === "{") {
throw new Error("Unexpected nested '{' beyond depth 2");
}
// If end of block -> single child optimization
if (serialized[cursor] === "}") {
top.set(key, { value, next: childKey, nextValue: firstValue });
cursor++; // Skip '}'
}
else {
const childMap = new Map();
childMap.set(childKey, firstValue);
let lastChildKey = childKey;
while (cursor < totalLength && serialized[cursor] !== "}") {
diff = readDiff();
childKey = lastChildKey + diff + 1;
const childValue = readEntity();
if (serialized[cursor] === "{") {
throw new Error("Unexpected nested '{' beyond depth 2");
}
childMap.set(childKey, childValue);
lastChildKey = childKey;
}
if (serialized[cursor] !== "}") {
throw new Error("Unterminated child block");
}
cursor++; // Skip '}'
top.set(key, { value, next: childMap });
}
}
else if (value === undefined) {
throw new Error(`Malformed encode trie: missing value at index ${cursor}`);
}
else {
top.set(key, value);
}
lastTopKey = key;
}
return top;
}
//# sourceMappingURL=encode-shared.js.map