rsms

// Optional declares a type of keyed type T where all keys are optional.
// This allows 
type Optional<T> = { [P in keyof T]? :T[P] }
  
interface Foo {
  x :number
  y :number
}

type OptionalFoo = Optional<Foo>

cboudereau

#r """..\packages\FSharp.Data\lib\net40\FSharp.Data.dll"""

open FSharp.Data

let [<Literal>] sample = """{
 "kind": "customsearch#search",
 "url": {
  "type": "application/json",
  "template": "https://www.googleapis.com/customsearch/v1?q={searchTerms}&num={count?}&start={startIndex?}&lr={language?}&safe={safe?}&cx={cx?}&sort={sort?}&filter={filter?}&gl={gl?}&cr={cr?}&googlehost={googleHost?}&c2coff={disableCnTwTranslation?}&hq={hq?}&hl={hl?}&siteSearch={siteSearch?}&siteSearchFilter={siteSearchFilter?}&exactTerms={exactTerms?}&excludeTerms={excludeTerms?}&linkSite={linkSite?}&orTerms={orTerms?}&relatedSite={relatedSite?}&dateRestrict={dateRestrict?}&lowRange={lowRange?}&highRange={highRange?}&searchType={searchType}&fileType={fileType?}&rights={rights?}&imgSize={imgSize?}&imgType={imgType?}&imgColorType={imgColorType?}&imgDominantColor={imgDominantColor?}&alt=json"
 },