genhtmlentity.ts

// @ts-ignore
import * as fs from "node:fs/promises";

interface EntityDefinition {
  characters: string;
}

const FILENAME = "fts5-html.c";
const entities: Record<string, EntityDefinition> = await fetch(
  "https://html.spec.whatwg.org/entities.json",
).then((r) => r.json());

const cleaned = Object.fromEntries(
  Object.entries(entities).map(([k, v]) => [k.replace(/^&(.*?);?$/g, "$1"), v]),
);

function strcmp(a: string, b: string): number {
  if (a < b) {
    return -1;
  } else if (a > b) {
    return 1;
  } else {
    return 0;
  }
}

const encoder = new TextEncoder();

const parts: string[] = [];

parts.push(
  `
struct htmlEntity {
	const char *pzName;
	const char *pzUtf8;
};
typedef struct htmlEntity htmlEntity;

static const htmlEntity htmlEntities[] = {
`.trim(),
);

for (const [name, { characters }] of Object.entries(cleaned).sort((a, b) =>
  strcmp(a[0], b[0]),
)) {
  const hex = encoder.encode(characters);
  const escaped = Array.from(hex)
    .map((h) => "\\x" + h.toString(16).padStart(2, "0"))
    .join("");
  parts.push(`\t{"${name}", "${escaped}"},`);
}

parts.push(`
	{0, 0}
};

#define MAX_ENTITY_NAME_LENGTH ${Math.max(...Object.keys(cleaned).map((k) => k.length))}
#define NUM_ENTITIES ${Object.keys(cleaned).length}
`);

const input = await fs.readFile(FILENAME, "utf-8");
let emit = true;
const outputParts: string[] = [];

for (let line of input.split("\n")) {
  if (line.includes("/* START OF HTML ENTITIES */")) {
    outputParts.push(line);
    emit = false;
  }
  if (emit) {
    outputParts.push(line);
  }
  if (line.includes("/* END OF HTML ENTITIES */")) {
    emit = true;
    outputParts.push(parts.join("\n"));
    outputParts.push(line);
  }
}

await fs.writeFile(FILENAME, outputParts.join("\n"));