Method parseArguments

static/katex/katex.mjs:15308–15363

* Parses the arguments of a function or environment

(func, // Should look like "\name" or "\begin{name}".
  funcData)

  parseArguments(func, // Should look like "\name" or "\begin{name}".
  funcData) {
    const totalArgs = funcData.numArgs + funcData.numOptionalArgs;

    if (totalArgs === 0) {
      return {
        args: [],
        optArgs: []
      };
    }

    const baseGreediness = funcData.greediness;
    const args = [];
    const optArgs = [];

    for (let i = 0; i < totalArgs; i++) {
      const argType = funcData.argTypes && funcData.argTypes[i];
      const isOptional = i < funcData.numOptionalArgs; // Ignore spaces between arguments.  As the TeXbook says:
      // "After you have said ‘\def\row#1#2{...}’, you are allowed to
      //  put spaces between the arguments (e.g., ‘\row x n’), because
      //  TeX doesn’t use single spaces as undelimited arguments."

      if (i > 0 && !isOptional) {
        this.consumeSpaces();
      } // Also consume leading spaces in math mode, as parseSymbol
      // won't know what to do with them.  This can only happen with
      // macros, e.g. \frac\foo\foo where \foo expands to a space symbol.
      // In LaTeX, the \foo's get treated as (blank) arguments).
      // In KaTeX, for now, both spaces will get consumed.
      // TODO(edemaine)


      if (i === 0 && !isOptional && this.mode === "math") {
        this.consumeSpaces();
      }

      const nextToken = this.nextToken;
      const arg = this.parseGroupOfType("argument to '" + func + "'", argType, isOptional, baseGreediness);

      if (!arg) {
        if (isOptional) {
          optArgs.push(null);
          continue;
        }

        throw new ParseError("Expected group after '" + func + "'", nextToken);
      }

      (isOptional ? optArgs : args).push(arg);
    }

    return {
      args,
      optArgs
    };
  }
  /**
   * Parses a group when the mode is changing.