[2/?] Add ability to run code examples in the playground: Extend code samples to be runnable

code-samples/aliasing-iso-to-tag.pony

@@ -1,2 +1,8 @@
-fun test(a: Wombat iso) =>
-  var b: Wombat tag = a // Allowed!
+actor Main
+  new create(env: Env) =>
+    test(Wombat)
+
+  fun test(a: Wombat iso) =>
+    var b: Wombat tag = a // Allowed!
+
+class Wombat

code-samples/aliasing-multiple-references-to-an-iso-object.pony

@@ -1,2 +1,8 @@
-fun test(a: Wombat iso) =>
-  var b: Wombat iso = a // Not allowed!
+actor Main
+  new create(env: Env) =>
+    test(Wombat)
+
+  fun test(a: Wombat iso) =>
+    var b: Wombat iso = a // Not allowed!
+
+class Wombat

code-samples/aliasing-trn-to-box.pony

@@ -1,2 +1,8 @@
-fun test(a: Wombat trn) =>
-  var b: Wombat box = a // Allowed!
+actor Main
+  new create(env: Env) =>
+    test(Wombat)
+
+  fun test(a: Wombat trn) =>
+    var b: Wombat box = a // Allowed!
+
+class Wombat

code-samples/appendices-annotations-empty-with-nosupertype-annotation.pony

@@ -4,4 +4,9 @@ class Foo
   fun foo[A: Any](a: (A | Empty val)) =>
     match consume a
     | let a': A => None
-    end
+    end
+
+actor Main
+  new create(env: Env) =>
+    let foo: Foo = Foo
+    env.out.print(foo.foo[Any]("Something").string())

code-samples/appendices-annotations-likely-and-unlikely-annotations.pony

@@ -1,16 +1,32 @@
-if \likely\ cond then
-  foo
-end
+type T is (U32|U8)
 
-while \unlikely\ cond then
-  bar
-end
+actor Main
+  new create(env: Env) =>
+    let foo = "foo"
+    let bar = "bar"
+    let baz = "baz"
+    var cond = true
+    let obj: U32 = 42
+    let expr: U32 = 42
+
+    if \likely\ cond then
+      foo
+    end
 
-repeat
-  baz
-until \likely\ cond end
+    cond = false
+    while \unlikely\ cond do
+      bar
+    end
 
-match obj
-| \likely\ expr => foo
-| \unlikely\ let capt: T => bar
-end
+    cond = true
+    repeat
+      baz
+    until \likely\ cond end
+
+    let res =
+    match obj
+    | \likely\ expr => foo
+    | \unlikely\ let capt: T => bar
+    end
+
+    env.out.print("res = " + res)

code-samples/appendices-annotations-packed-annotation.pony

@@ -1,3 +1,11 @@
 struct \packed\ MyPackedStruct
   var x: U8
-  var y: U32
+  var y: U32
+
+  new create() =>
+    x = 0
+    y = 1
+
+actor Main
+  new create(env: Env) =>
+    env.out.print("{\n\t\"x\": " + MyPackedStruct.x.string() + ",\n\t\"y\": " + MyPackedStruct.y.string() + "\n}")

code-samples/appendices-examples-create-arrays-with-values.pony

@@ -1,5 +1,25 @@
-let dice: Array[U32] = [1; 2; 3
-  4
-  5
-  6
-]
+use "random"
+
+actor Main
+  new create(env: Env) =>
+    let dice: Array[U32] = [1; 2; 3
+      4
+      5
+      6
+    ]
+    Rand.shuffle[U32](dice)
+    for numberOfSpots in dice.values() do
+      env.out.print("You rolled a " + _ordinal(numberOfSpots))
+    end
+
+  fun _ordinal(number: U32): String =>
+    match number
+    | 1 => "one"
+    | 2 => "two"
+    | 3 => "three"
+    | 4 => "four"
+    | 5 => "five"
+    | 6 => "six"
+    else
+      "out of range"
+    end

code-samples/appendices-examples-enumeration-with-values-with-namespace.pony

@@ -1,3 +1,20 @@
+use "format"
+use "collections/persistent"
+
 primitive Colours
   fun black(): U32 => 0xFF000000
-  fun red(): U32 => 0xFFFF0000
+  fun red(): U32 => 0xFFFF0000
+
+interface val Applyable
+  fun apply(): U32
+
+actor Main
+  new create(env: Env) =>
+    let colorMap: Map[String, Applyable] = Map[String, Applyable].concat([
+      ("red", Colours~red())
+      ("black", Colours~black())
+    ].values())
+
+    for (colorName, color) in colorMap.pairs() do
+      env.out.print(colorName + ": #" + Format.int[U32](color(), FormatHexBare))
+    end

code-samples/appendices-examples-enumeration-with-values.pony

@@ -1,2 +1,19 @@
+use "format"
+use "collections/persistent"
+
 primitive Black fun apply(): U32 => 0xFF000000
-primitive Red   fun apply(): U32 => 0xFFFF0000
+primitive Red   fun apply(): U32 => 0xFFFF0000
+
+type Color is (Red | Black)
+
+actor Main
+  new create(env: Env) =>
+
+    let colorMap: Map[String, Color] = Map[String, Color].concat([
+      ("red", Red)
+      ("black", Black)
+    ].values())
+
+    for (colorName, color) in colorMap.pairs() do
+      env.out.print(colorName + ": #" + Format.int[U32](color(), FormatHexBare))
+    end

code-samples/appendices-whitespace-do-a-then-do-a-unary-negation-of-b.pony

@@ -1,2 +1,16 @@
-a
--b
+use "format"
+use "collections/persistent"
+
+primitive Black fun apply(): U32 => 0xFF000000
+primitive Red   fun apply(): U32 => 0xFFFF0000
+
+type Color is (Red | Black)
+
+actor Main
+  new create(env: Env) =>
+    let a: I8 = 1
+    let b: I8 = 3
+    let c: I8 = 
+      a
+      -b
+    env.out.print(c.string())

code-samples/appendices-whitespace-subtract-b-from-a.pony

@@ -1 +1,15 @@
-a - b
+use "format"
+use "collections/persistent"
+
+primitive Black fun apply(): U32 => 0xFF000000
+primitive Red   fun apply(): U32 => 0xFFFF0000
+
+type Color is (Red | Black)
+
+actor Main
+  new create(env: Env) =>
+    let a: I8 = 1
+    let b: I8 = 3
+    let c: I8 = 
+      a - b
+    env.out.print(c.string())

code-samples/arithmetic-partial-and-check-arithmetic.pony

@@ -1,17 +1,26 @@
-// partial arithmetic
-let result =
-  try
-    USize.max_value() +? env.args.size()
-  else
-    env.out.print("overflow detected")
-  end
+actor Main
+  new create(env: Env) =>
+    partial(env)
+    checked(env)
+
+  fun partial(env: Env) =>
+    // partial arithmetic
+    let result =
+      try
+        USize.max_value() +? env.args.size()
+      else
+        env.out.print("overflow detected")
+      end
 
-// checked arithmetic
-let result =
-  match USize.max_value().addc(env.args.size())
-  | (let result: USize, false) =>
-    // use result
-    ...
-  | (_, true) =>
-    env.out.print("overflow detected")
-  end
+  fun checked(env: Env) =>
+    // checked arithmetic
+    let result =
+      match USize.max_value().addc(env.args.size())
+      | (let result: USize, false) =>
+        // use result
+        env.out.print(result.string())/*
+        ...
+        */
+      | (_, true) =>
+        env.out.print("overflow detected")
+      end

code-samples/as-operator-match-statement-comparison.pony

@@ -1,3 +1,13 @@
+interface Critter
+  fun wash(): String
+
+class Wombat is Critter
+  fun wash(): String => "I'm a clean wombat!"
+
+class Capybara is Critter
+  fun wash(): String => "I feel squeaky clean!"
+  fun swim(): String => "I'm swimming like a fish!"
+
 actor Main
   new create(env: Env) =>
     let anys = Array[Any ref].>push(Wombat).>push(Capybara)

code-samples/as-operator-match-statement-without-try.pony

@@ -1,3 +1,13 @@
+interface Critter
+  fun wash(): String
+
+class Wombat is Critter
+  fun wash(): String => "I'm a clean wombat!"
+
+class Capybara is Critter
+  fun wash(): String => "I feel squeaky clean!"
+  fun swim(): String => "I'm swimming like a fish!"
+
 actor Main
   new create(env: Env) =>
     let anys = Array[Any ref].>push(Wombat).>push(Capybara)

code-samples/as-operator-more-specific-interface-with-reference-capability.pony

@@ -1,3 +1,13 @@
+interface Critter
+  fun wash(): String
+
+class Wombat is Critter
+  fun wash(): String => "I'm a clean wombat!"
+
+class Capybara is Critter
+  fun wash(): String => "I feel squeaky clean!"
+  fun swim(): String => "I'm swimming like a fish!"
+
 actor Main
   new create(env: Env) =>
     let anys = Array[Any ref].>push(Wombat).>push(Capybara)

code-samples/as-operator-unrelated-type.pony

@@ -1,10 +1,25 @@
-  trait Alive
+trait Alive
 
-  trait Well
+trait Well
 
-  class Person is (Alive & Well)
+class Person is (Alive & Well)
 
-  class LifeSigns
-    fun is_all_good(alive: Alive)? =>
-      // if the instance 'alive' is also of type 'Well' (such as a Person instance). raises error if not possible
-      let well: Well = alive as Well
+class LifeSigns
+  fun is_all_good(alive: Alive)? =>
+    // if the instance 'alive' is also of type 'Well' (such as a Person instance). raises error if not possible
+    let well: Well = alive as Well
+
+class Dog is Alive
+
+actor Main
+  new create(env: Env) =>
+    try
+      LifeSigns.is_all_good(Person)?
+    else
+      env.err.print("Person is alive but not well")
+    end
+    try
+      LifeSigns.is_all_good(Dog)?
+    else
+      env.err.print("Dog is alive but not well")
+    end

code-samples/c-abi-jump-consistent-hashing.pony

@@ -1,15 +1,19 @@
-// Jump consistent hashing in Pony, with an inline pseudo random generator
-// https://arxiv.org/abs/1406.2294
+actor Main
+  new create(env: Env) =>
+    env.out.print("jch: " + jch(U64(10), U32(20)).string())
 
-fun jch(key: U64, buckets: U32): I32 =>
-  var k = key
-  var b = I64(0)
-  var j = I64(0)
+  // Jump consistent hashing in Pony, with an inline pseudo random generator
+  // https://arxiv.org/abs/1406.2294
 
-  while j < buckets.i64() do
-    b = j
-    k = (k * 2862933555777941757) + 1
-    j = ((b + 1).f64() * (I64(1 << 31).f64() / ((k >> 33) + 1).f64())).i64()
-  end
-
-  b.i32()
+  fun jch(key: U64, buckets: U32): I32 =>
+    var k = key
+    var b = I64(0)
+    var j = I64(0)
+
+    while j < buckets.i64() do
+      b = j
+      k = (k * 2862933555777941757) + 1
+      j = ((b + 1).f64() * (I64(1 << 31).f64() / ((k >> 33) + 1).f64())).i64()
+    end
+
+    b.i32()