Function flattenForm

src/compute-engine/boxed-expression/canonical.ts:94–125

* Apply the "Flatten" form to the expression: * - remove delimiters * - flatten associative functions * * This function is recursive.

(expr: Expression)

        expr = numberForm(expr);
        break;
      case 'Multiply':
        expr = multiplyForm(expr);
        break;
      case 'Add':
        expr = addForm(expr);
        break;
      case 'Power':
        expr = powerForm(expr);
        break;
      case 'Divide':
        expr = divideForm(expr);
        break;
      case 'Flatten':
        // Flatten ops, delimiters and sequences
        expr = flattenForm(expr);
        break;
      case 'Order':
        expr = canonicalOrder(expr, { recursive: true });
        break;
      default:
        throw Error('Invalid canonical form');
    }
  }

  // Partial canonicalization produces a structural expression, not a fully
  // canonical one. This allows subsequent .canonical calls to perform full
  // canonicalization.
  if (isFunction(expr) && expr.isCanonical) {
    expr = expr.engine.function(expr.operator, [...expr.ops!], {
      form: 'structural',
    });
  }

  return expr;
}