Method parseAtom

static/katex/katex.mjs:15136–15236

* Parses a group with optional super/subscripts.

(breakOnTokenText)

  parseAtom(breakOnTokenText) {
    // The body of an atom is an implicit group, so that things like
    // \left(x\right)^2 work correctly.
    const base = this.parseGroup("atom", false, null, breakOnTokenText); // In text mode, we don't have superscripts or subscripts

    if (this.mode === "text") {
      return base;
    } // Note that base may be empty (i.e. null) at this point.


    let superscript;
    let subscript;

    while (true) {
      // Guaranteed in math mode, so eat any spaces first.
      this.consumeSpaces(); // Lex the first token

      const lex = this.nextToken;

      if (lex.text === "\\limits" || lex.text === "\\nolimits") {
        // We got a limit control
        const opNode = checkNodeType(base, "op");

        if (opNode) {
          const limits = lex.text === "\\limits";
          opNode.limits = limits;
          opNode.alwaysHandleSupSub = true;
        } else {
          throw new ParseError("Limit controls must follow a math operator", lex);
        }

        this.consume();
      } else if (lex.text === "^") {
        // We got a superscript start
        if (superscript) {
          throw new ParseError("Double superscript", lex);
        }

        superscript = this.handleSupSubscript("superscript");
      } else if (lex.text === "_") {
        // We got a subscript start
        if (subscript) {
          throw new ParseError("Double subscript", lex);
        }

        subscript = this.handleSupSubscript("subscript");
      } else if (lex.text === "'") {
        // We got a prime
        if (superscript) {
          throw new ParseError("Double superscript", lex);
        }

        const prime = {
          type: "textord",
          mode: this.mode,
          text: "\\prime"
        }; // Many primes can be grouped together, so we handle this here