Merge branch 'zahary' into araq

4 files changed, 121 insertions, 1 deletions

diff --git a/tests/concepts/t5642.nim b/tests/concepts/t5642.nim
new file mode 100644
index 000000000..d1e7bd1dd
--- /dev/null
+++ b/tests/concepts/t5642.nim
@@ -0,0 +1,25 @@
+discard """
+  output: 9
+"""
+
+type DataTable = concept x
+  x is object
+  for f in fields(x):
+    f is seq
+
+type Students = object
+   id : seq[int]
+   name : seq[string]
+   age: seq[int]
+
+proc nrow*(dt: DataTable) : Natural =
+  var totalLen = 0
+  for f in fields(dt):
+    totalLen += f.len
+  return totalLen
+
+let
+ stud = Students (id : @[1,2,3], name : @["Vas", "Pas", "NafNaf"], age : @[10,16,32])
+
+echo nrow(stud)
+
diff --git a/tests/concepts/tconceptinclosure.nim b/tests/concepts/tconceptinclosure.nim
new file mode 100644
index 000000000..23c1bf293
--- /dev/null
+++ b/tests/concepts/tconceptinclosure.nim
@@ -0,0 +1,53 @@
+discard """
+  output: '''
+10
+20
+int
+20
+3
+'''
+"""
+
+import typetraits
+
+type
+  FonConcept = concept x
+    x.x is int
+
+  GenericConcept[T] = concept x
+    x.x is T
+    const L = T.name.len
+
+  Implementation = object
+    x: int
+
+  Closure = object
+    f: proc()
+
+proc f1(x: FonConcept): Closure =
+  result.f = proc () =
+    echo x.x
+
+proc f2(x: GenericConcept): Closure =
+  result.f = proc () =
+    echo x.x
+    echo GenericConcept.T.name
+
+proc f3[T](x: GenericConcept[T]): Closure =
+  result.f = proc () =
+    echo x.x
+    echo x.L
+
+let x = Implementation(x: 10)
+let y = Implementation(x: 20)
+
+let a = x.f1
+let b = x.f2
+let c = x.f1
+let d = y.f2
+let e = y.f3
+
+a.f()
+d.f()
+e.f()
+
diff --git a/tests/concepts/tmisc_issues.nim b/tests/concepts/tmisc_issues.nim
index 10e072521..d9bb84a2f 100644
--- a/tests/concepts/tmisc_issues.nim
+++ b/tests/concepts/tmisc_issues.nim
@@ -42,7 +42,7 @@ echo p2 is AbstractPointOfFloat      # true
 echo p2.x is float and p2.y is float # true
 
 # https://github.com/nim-lang/Nim/issues/2018
-type ProtocolFollower = generic
+type ProtocolFollower = concept
   true # not a particularly involved protocol
 
 type ImplementorA = object
diff --git a/tests/concepts/trandom_vars.nim b/tests/concepts/trandom_vars.nim
new file mode 100644
index 000000000..a236cebad
--- /dev/null
+++ b/tests/concepts/trandom_vars.nim
@@ -0,0 +1,42 @@
+discard """
+output: "11.0"
+"""
+
+type
+  # A random number generator
+  Random = object
+    random: proc(): float
+  # A generic typeclass for a random var
+  RandomVar[A] = concept x
+    var rng: Random
+    rng.sample(x) is A
+  # A few concrete instances
+  Uniform = object
+    a, b: float
+  ClosureVar[A] = object
+    f: proc(rng: var Random): A
+
+# How to sample from various concrete instances
+proc sample(rng: var Random, u: Uniform): float = u.a + (u.b - u.a) * rng.random()
+
+proc sample[A](rng: var Random, c: ClosureVar[A]): A = c.f(rng)
+
+proc uniform(a, b: float): Uniform = Uniform(a: a, b: b)
+
+# How to lift a function on values to a function on random variables
+proc map[A, B](x: RandomVar[A], f: proc(a: A): B): ClosureVar[B] =
+  proc inner(rng: var Random): B =
+    f(rng.sample(x))
+
+  result.f = inner
+
+import future
+
+proc fakeRandom(): Random =
+  result.random = () => 0.5
+
+let x = uniform(1, 10).map((x: float) => 2 * x)
+
+var rng = fakeRandom()
+
+echo rng.sample(x)