Function def

static/katex/katex.mjs:13177–13215

(context, global)

// Also the \gdef and \global\def equivalents

const def = (context, global) => {
  let arg = context.consumeArgs(1)[0];

  if (arg.length !== 1) {
    throw new ParseError("\\gdef's first argument must be a macro name");
  }

  const name = arg[0].text; // Count argument specifiers, and check they are in the order #1 #2 ...

  let numArgs = 0;
  arg = context.consumeArgs(1)[0];

  while (arg.length === 1 && arg[0].text === "#") {
    arg = context.consumeArgs(1)[0];

    if (arg.length !== 1) {
      throw new ParseError(`Invalid argument number length "${arg.length}"`);
    }

    if (!/^[1-9]$/.test(arg[0].text)) {
      throw new ParseError(`Invalid argument number "${arg[0].text}"`);
    }

    numArgs++;

    if (parseInt(arg[0].text) !== numArgs) {
      throw new ParseError(`Argument number "${arg[0].text}" out of order`);
    }

    arg = context.consumeArgs(1)[0];
  } // Final arg is the expansion of the macro


  context.macros.set(name, {
    tokens: arg,
    numArgs
  }, global);
  return '';
};

defineMacro("\\gdef", context => def(context, true));
defineMacro("\\def", context => def(context, false));