Function matchVariation

src/compute-engine/boxed-expression/match.ts:378–384

(op: string, ops: ReadonlyArray<ExpressionInput>)

/** Assuming expr is a function, attempts to match the patterns
 * to the arguments of the function.
 */
function matchRecursive(
  expr: Expression,
  pattern: Expression,
  substitution: BoxedSubstitution,
  options: MatchOptions
): BoxedSubstitution | null {
  console.assert(isFunction(expr));
  if (!isFunction(expr)) return null;