Function matchesNumber

src/math-json/utils.ts:501–512

(s: string)

/** True if the string matches the expected pattern for a number */
export function matchesNumber(s: string): boolean {
  return (
    /^(nan|oo|\+oo|-oo|infinity|\+infinity|-infinity)$/i.test(s) ||
    // Optional fraction part where, after the decimal point, at least one of
    // {fractional digits, repeating-decimal group} is present. This accepts the
    // digit-less repetend form `0.(3)` (per the MathJSON spec's `1.(3)` example)
    // while still rejecting a bare trailing `.` (e.g. `5.`).
    /^[+-]?(0|[1-9][0-9]*)(\.([0-9]+(\([0-9]+\))?|\([0-9]+\)))?([eE][+-]?[0-9]+)?$/.test(
      s
    )
  );
}

/** True if the string matches the expected pattern for a symbol */
export function matchesSymbol(s: string): boolean {