1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
package forge
import forge.define.Applicative
import utest._
import language.experimental.macros
object ApplicativeTests extends TestSuite {
implicit def optionToOpt[T](o: Option[T]): Opt[T] = new Opt(o)
class Opt[T](val o: Option[T]) extends Applicative.Applyable[T]
object Opt extends define.Applicative.Applyer[Opt, Option]{
def underlying[A](v: Opt[A]) = v.o
def apply[T](t: Option[T]): Option[T] = macro Applicative.impl0[Option, T]
def apply[T](t: T): Option[T] = macro Applicative.impl[Option, T]
type O[+T] = Option[T]
def map[A, B](a: O[A], f: A => B) = a.map(f)
def zip() = Some(())
def zip[A](a: O[A]) = a.map(Tuple1(_))
def zip[A, B](a: O[A], b: O[B]) = {
for(a <- a; b <- b) yield (a, b)
}
def zip[A, B, C](a: O[A], b: O[B], c: O[C]) = {
for(a <- a; b <- b; c <- c) yield (a, b, c)
}
def zip[A, B, C, D](a: O[A], b: O[B], c: O[C], d: O[D]) = {
for(a <- a; b <- b; c <- c; d <- d) yield (a, b, c, d)
}
def zip[A, B, C, D, E](a: O[A], b: O[B], c: O[C], d: O[D], e: O[E]) = {
for(a <- a; b <- b; c <- c; d <- d; e <- e) yield (a, b, c, d, e)
}
def zip[A, B, C, D, E, F](a: O[A], b: O[B], c: O[C], d: O[D], e: O[E], f: O[F]) ={
for(a <- a; b <- b; c <- c; d <- d; e <- e; f <- f) yield (a, b, c, d, e, f)
}
def zip[A, B, C, D, E, F, G](a: O[A], b: O[B], c: O[C], d: O[D], e: O[E], f: O[F], g: O[G]) = {
for(a <- a; b <- b; c <- c; d <- d; e <- e; f <- f; g <- g) yield (a, b, c, d, e, f, g)
}
}
class Counter{
var value = 0
def apply() = {
value += 1
value
}
}
val tests = Tests{
'selfContained - {
'simple - assert(Opt("lol " + 1) == Some("lol 1"))
'singleSome - assert(Opt("lol " + Some("hello")()) == Some("lol hello"))
'twoSomes - assert(Opt(Some("lol ")() + Some("hello")()) == Some("lol hello"))
'singleNone - assert(Opt("lol " + None()) == None)
'twoNones - assert(Opt("lol " + None() + None()) == None)
}
'capturing - {
val lol = "lol "
def hell(o: String) = "hell" + o
'simple - assert(Opt(lol + 1) == Some("lol 1"))
'singleSome - assert(Opt(lol + Some(hell("o"))()) == Some("lol hello"))
'twoSomes - assert(Opt(Some(lol)() + Some(hell("o"))()) == Some("lol hello"))
'singleNone - assert(Opt(lol + None()) == None)
'twoNones - assert(Opt(lol + None() + None()) == None)
}
'allowedLocalDef - {
// Although x is defined inside the Opt{...} block, it is also defined
// within the LHS of the Applyable#apply call, so it is safe to life it
// out into the `zipMap` arguments list.
val res = Opt{ "lol " + Some("hello").flatMap(x => Some(x)).apply() }
assert(res == Some("lol hello"))
}
'upstreamAlwaysEvaluated - {
// Whether or not control-flow reaches the Applyable#apply call inside an
// Opt{...} block, we always evaluate the LHS of the Applyable#apply
// because it gets lifted out of any control flow statements
val counter = new Counter()
def up = Opt{ "lol " + counter() }
val down = Opt{ if ("lol".length > 10) up() else "fail" }
assert(
down == Some("fail"),
counter.value == 1
)
}
'upstreamEvaluatedOnlyOnce - {
// Even if control-flow reaches the Applyable#apply call more than once,
// it only gets evaluated once due to its lifting out of the Opt{...} block
val counter = new Counter()
def up = Opt{ "lol " + counter() }
def runTwice[T](t: => T) = (t, t)
val down = Opt{ runTwice(up()) }
assert(
down == Some(("lol 1", "lol 1")),
counter.value == 1
)
}
}
}
|