Function atom

src/math-json/parse-sympy.ts:295–309

(
  s: string,
  start: number
)

function atom(
  s: string,
  start: number
): [index: number, result: Expression | null] {
  let [i, e] = identifier(s, start);
  if (e) return [i, e];

  [i, e] = literal(s, start);
  if (e) return [i, e];

  [i, e] = enclosure(s, start);
  if (e) return [i, e];

  return [start, null];
}

// expression_list    ::=  expression ("," expression)* [","]
function expressionList(
  s: string,