A syntax parse example for parsing subterms in arbitrary order.

gistfile1.txt

#lang racket

(require (for-syntax syntax/parse))

(struct person (name age) #:transparent)

;; Accept name and age in any order:
(define-syntax (new-person stx)
  (syntax-parse stx 
    [(_ (~or (~optional ((~datum name) name) #:defaults ([name #'"Jane Doe"]))
             (~optional ((~datum age) age) #:defaults ([age #'#f])))
        ...)
     #'(person name age)]))
    
(new-person (age 34))
(new-person (name "Pen Pen"))
(new-person (age 48) (name "Gendo Ikari"))