test/Constraints/function_builder.swift

// RUN: %target-run-simple-swift | %FileCheck %s
// REQUIRES: executable_test

enum Either<T,U> {
  case first(T)
  case second(U)
}

@_functionBuilder
struct TupleBuilder {
  static func buildBlock<T1, T2>(_ t1: T1, _ t2: T2) -> (T1, T2) {
    return (t1, t2)
  }
  
  static func buildBlock<T1, T2, T3>(_ t1: T1, _ t2: T2, _ t3: T3)
      -> (T1, T2, T3) {
    return (t1, t2, t3)
  }

  static func buildBlock<T1, T2, T3, T4>(_ t1: T1, _ t2: T2, _ t3: T3, _ t4: T4)
      -> (T1, T2, T3, T4) {
    return (t1, t2, t3, t4)
  }

  static func buildBlock<T1, T2, T3, T4, T5>(
    _ t1: T1, _ t2: T2, _ t3: T3, _ t4: T4, _ t5: T5
  ) -> (T1, T2, T3, T4, T5) {
    return (t1, t2, t3, t4, t5)
  }

  static func buildDo<T>(_ value: T) -> T { return value }
  static func buildIf<T>(_ value: T?) -> T? { return value }

  static func buildEither<T,U>(first value: T) -> Either<T,U> {
    return .first(value)
  }
  static func buildEither<T,U>(second value: U) -> Either<T,U> {
    return .second(value)
  }
}

func tuplify<T>(_ cond: Bool, @TupleBuilder body: (Bool) -> T) {
  print(body(cond))
}

// CHECK: (17, 3.14159, "Hello, DSL", (["nested", "do"], 6), Optional((2.71828, ["if", "stmt"])))
let name = "dsl"
tuplify(true) {
  17
  3.14159
  "Hello, \(name.map { $0.uppercased() }.joined())"
  do {
    ["nested", "do"]
    1 + 2 + 3
  }
  if $0 {
    2.71828
    ["if", "stmt"]
  }
}

// CHECK: ("Empty optional", nil)
tuplify(false) {
  "Empty optional"
  if $0 {
    2.71828
    ["if", "stmt"]
  }
}

// CHECK: ("chain0", main.Either<(Swift.String, Swift.Double), (Swift.Double, Swift.String)>.second(2.8, "capable"))
tuplify(false) {
  "chain0"
  if $0 {
    "marginal"
    2.9
  } else {
    2.8
    "capable"
  }
}

// CHECK: ("chain1", nil)
tuplify(false) {
  "chain1"
  if $0 {
    "marginal"
    2.9
  } else if $0 {
    2.8
    "capable"
  }
}

// CHECK: ("chain2", Optional(main.Either<(Swift.String, Swift.Double), (Swift.Double, Swift.String)>.first("marginal", 2.9)))
tuplify(true) {
  "chain2"
  if $0 {
    "marginal"
    2.9
  } else if $0 {
    2.8
    "capable"
  }
}

// CHECK: ("chain3", main.Either<main.Either<(Swift.String, Swift.Double), (Swift.Double, Swift.String)>, main.Either<(Swift.Double, Swift.Double), (Swift.String, Swift.String)>>.first(main.Either<(Swift.String, Swift.Double), (Swift.Double, Swift.String)>.first("marginal", 2.9)))
tuplify(true) {
  "chain3"
  if $0 {
    "marginal"
    2.9
  } else if $0 {
    2.8
    "capable"
  } else if $0 {
    2.8
    1.0
  } else {
    "wild"
    "broken"
  }
}

// CHECK: ("chain4", main.Either<main.Either<main.Either<(Swift.String, Swift.Int), (Swift.String, Swift.Int)>, main.Either<(Swift.String, Swift.Int), (Swift.String, Swift.Int)>>, main.Either<main.Either<(Swift.String, Swift.Int), (Swift.String, Swift.Int)>, (Swift.String, Swift.Int)>>.first
tuplify(true) {
  "chain4"
  if $0 {
    "0"
    0
  } else if $0 {
    "1"
    1
  } else if $0 {
    "2"
    2
  } else if $0 {
    "3"
    3
  } else if $0 {
    "4"
    4
  } else if $0 {
    "5"
    5
  } else {
    "6"
    6
  }
}

// rdar://50710698
// CHECK: ("chain5", 8, 9)
tuplify(true) {
  "chain5"
  #if false
    6
    $0
  #else
    8
    9
  #endif
}

// CHECK: ("getterBuilder", 0, 4, 12)
@TupleBuilder
var globalBuilder: (String, Int, Int, Int) {
  "getterBuilder"
  0
  4
  12
}
print(globalBuilder)

// CHECK: ("funcBuilder", 13, 45.0)
@TupleBuilder
func funcBuilder(d: Double) -> (String, Int, Double) {
  "funcBuilder"
  13
  d
}
print(funcBuilder(d: 45))

struct MemberBuilders {
  @TupleBuilder
  func methodBuilder(_ i: Int) -> (String, Int) {
    "methodBuilder"
    i
  }

  @TupleBuilder
  static func staticMethodBuilder(_ i: Int) -> (String, Int) {
    "staticMethodBuilder"
    i + 14
  }

  @TupleBuilder
  var propertyBuilder: (String, Int) {
    "propertyBuilder"
    12
  }
}

// CHECK: ("staticMethodBuilder", 27)
print(MemberBuilders.staticMethodBuilder(13))

let mbuilders = MemberBuilders()

// CHECK: ("methodBuilder", 13)
print(mbuilders.methodBuilder(13))

// CHECK: ("propertyBuilder", 12)
print(mbuilders.propertyBuilder)

// SR-11439: Operator builders
infix operator ^^^
func ^^^ (lhs: Int, @TupleBuilder rhs: (Int) -> (String, Int)) -> (String, Int) {
  return rhs(lhs)
}

// CHECK: ("hello", 6)
print(5 ^^^ {
  "hello"
  $0 + 1
})

struct Tagged<Tag, Entity> {
  let tag: Tag
  let entity: Entity
}

protocol Taggable {
}

extension Taggable {
  func tag<Tag>(_ tag: Tag) -> Tagged<Tag, Self> {
    return Tagged(tag: tag, entity: self)
  }
}

extension Int: Taggable { }
extension String: Taggable { }
extension Double: Taggable { }

@_functionBuilder
struct TaggedBuilder<Tag> {
  static func buildBlock() -> () { }

  static func buildBlock<T1>(_ t1: Tagged<Tag, T1>) -> Tagged<Tag, T1> {
    return t1
  }

  static func buildBlock<T1, T2>(_ t1: Tagged<Tag, T1>, _ t2: Tagged<Tag, T2>) -> (Tagged<Tag, T1>, Tagged<Tag, T2>) {
    return (t1, t2)
  }

  static func buildBlock<T1, T2, T3>(_ t1: Tagged<Tag, T1>, _ t2: Tagged<Tag, T2>, _ t3: Tagged<Tag, T3>)
      -> (Tagged<Tag, T1>, Tagged<Tag, T2>, Tagged<Tag, T3>) {
    return (t1, t2, t3)
  }

  static func buildBlock<T1, T2, T3, T4>(_ t1: Tagged<Tag, T1>, _ t2: Tagged<Tag, T2>, _ t3: Tagged<Tag, T3>, _ t4: Tagged<Tag, T4>)
      -> (Tagged<Tag, T1>, Tagged<Tag, T2>, Tagged<Tag, T3>, Tagged<Tag, T4>) {
    return (t1, t2, t3, t4)
  }

  static func buildBlock<T1, T2, T3, T4, T5>(
    _ t1: Tagged<Tag, T1>, _ t2: Tagged<Tag, T2>, _ t3: Tagged<Tag, T3>, _ t4: Tagged<Tag, T4>, _ t5: Tagged<Tag, T5>
  ) -> (Tagged<Tag, T1>, Tagged<Tag, T2>, Tagged<Tag, T3>, Tagged<Tag, T4>, Tagged<Tag, T5>) {
    return (t1, t2, t3, t4, t5)
  }

  static func buildIf<T>(_ value: Tagged<Tag, T>?) -> Tagged<Tag, T>? { return value }
}

enum Color {
  case red, green, blue
}

func acceptColorTagged<Result>(@TaggedBuilder<Color> body: () -> Result) {
  print(body())
}

struct TagAccepter<Tag> {
  static func acceptTagged<Result>(@TaggedBuilder<Tag> body: () -> Result) {
    print(body())
  }
}

func testAcceptColorTagged(b: Bool, i: Int, s: String, d: Double) {
  // FIXME: When we support buildExpression, drop the "Color" prefix
  // CHECK: Tagged<
  acceptColorTagged {
    i.tag(Color.red)
    s.tag(Color.green)
    d.tag(Color.blue)
  }

  // FIXME: When we support buildExpression, drop the "Color" prefix
  // CHECK: Tagged<
  TagAccepter<Color>.acceptTagged {
    i.tag(Color.red)
    s.tag(Color.green)
    d.tag(Color.blue)
  }

  // CHECK: Tagged<
  TagAccepter<Color>.acceptTagged { () -> Tagged<Color, Int> in 
    if b {
      return i.tag(Color.green)
    } else {
      return i.tag(Color.blue)
    }
  }
}

testAcceptColorTagged(b: true, i: 17, s: "Hello", d: 3.14159)

// rdar://53325810

// Test that we don't have problems with expression pre-checking when
// type-checking an overloaded function-builder call.  In particular,
// we need to make sure that expressions in the closure are pre-checked
// before we build constraints for them.  Note that top-level expressions
// that need to be rewritten by expression prechecking (such as the operator
// sequences in the boolean conditions and statements below) won't be
// rewritten in the original closure body if we just precheck the
// expressions produced by the function-builder transformation.
struct ForEach1<Data : RandomAccessCollection, Content> {
  var data: Data
  var content: (Data.Element) -> Content

  func show() {
    print(content(data.first!))
    print(content(data.last!))
  }
}
extension ForEach1 where Data.Element: StringProtocol {
  // Checking this overload shouldn't trigger inappropriate caching that
  // affects checking the next overload.
  init(_ data: Data,
       @TupleBuilder content: @escaping (Data.Element) -> Content) {
    self.init(data: data, content: content)
  }
}
extension ForEach1 where Data == Range<Int> {
  // This is the overload we actually want.
  init(_ data: Data,
       @TupleBuilder content: @escaping (Int) -> Content) {
    self.init(data: data, content: content)
  }
}
let testForEach1 = ForEach1(-10 ..< 10) { i in
  "testForEach1"
  if i < 0 {
    "begin"
    i < -5
  } else {
    i > 5
    "end"
  }
}
testForEach1.show()

// CHECK: ("testForEach1", main.Either<(Swift.String, Swift.Bool), (Swift.Bool, Swift.String)>.first("begin", true))
// CHECK: ("testForEach1", main.Either<(Swift.String, Swift.Bool), (Swift.Bool, Swift.String)>.second(true, "end"))