Merge pull request #1921 from hjwylde/hjwylde/type-signature-updates

Type signature updates for Enumerable, Module, Range, Array

core/array.rbs

@@ -1082,7 +1082,7 @@ class Array[unchecked out Elem] < Object
   #     a.at(0) # => :foo
   #     a.at(2) # => 2
   #
-  def at: (int index) -> Elem?
+  def at: %a{implicitly-returns-nil} (int index) -> Elem
 
   # <!--
   #   rdoc-file=array.c
@@ -1378,7 +1378,7 @@ class Array[unchecked out Elem] < Object
   #
   # If `index` is too small (far from zero), returns nil.
   #
-  def delete_at: (int index) -> Elem?
+  def delete_at: %a{implicitly-returns-nil} (int index) -> Elem
 
   # <!--
   #   rdoc-file=array.c
@@ -1942,7 +1942,7 @@ class Array[unchecked out Elem] < Object
   #
   # Related: #last.
   #
-  def first: () -> Elem?
+  def first: %a{implicitly-returns-nil} () -> Elem
            | (int n) -> ::Array[Elem]
 
   # <!--
@@ -2241,7 +2241,7 @@ class Array[unchecked out Elem] < Object
   #
   # Related: #first.
   #
-  def last: () -> Elem?
+  def last: %a{implicitly-returns-nil} () -> Elem
           | (int n) -> ::Array[Elem]
 
   # <!--
@@ -2321,8 +2321,8 @@ class Array[unchecked out Elem] < Object
   #
   #     ['0', '00', '000'].max(2) {|a, b| a.size <=> b.size } # => ["000", "00"]
   #
-  def max: () -> Elem?
-         | () { (Elem a, Elem b) -> ::Integer? } -> Elem?
+  def max: %a{implicitly-returns-nil} () -> Elem
+         | %a{implicitly-returns-nil} () { (Elem a, Elem b) -> ::Integer? } -> Elem
          | (int n) -> ::Array[Elem]
          | (int n) { (Elem a, Elem b) -> ::Integer? } -> ::Array[Elem]
 
@@ -3118,7 +3118,7 @@ class Array[unchecked out Elem] < Object
   #     a.sample(random: Random.new(1))     #=> 6
   #     a.sample(4, random: Random.new(1))  #=> [6, 10, 9, 2]
   #
-  def sample: (?random: _Rand rng) -> Elem?
+  def sample: %a{implicitly-returns-nil} (?random: _Rand rng) -> Elem
             | (int n, ?random: _Rand rng) -> ::Array[Elem]
 
   # <!--
@@ -3197,7 +3197,7 @@ class Array[unchecked out Elem] < Object
   #
   # Related: #push, #pop, #unshift.
   #
-  def shift: () -> Elem?
+  def shift: %a{implicitly-returns-nil} () -> Elem
            | (int n) -> ::Array[Elem]
 
   # <!--
@@ -3323,7 +3323,7 @@ class Array[unchecked out Elem] < Object
   #     # Raises TypeError (no implicit conversion of Symbol into Integer):
   #     a[:foo]
   #
-  def slice: (int index) -> Elem?
+  def slice: %a{implicitly-returns-nil} (int index) -> Elem
            | (int start, int length) -> ::Array[Elem]?
            | (::Range[::Integer] range) -> ::Array[Elem]?
 
@@ -3393,7 +3393,7 @@ class Array[unchecked out Elem] < Object
   #     a.slice!(-2..2) # => ["bar", 2]
   #     a # => [:foo]
   #
-  def slice!: (int index) -> Elem?
+  def slice!: %a{implicitly-returns-nil} (int index) -> Elem
             | (int start, int length) -> ::Array[Elem]?
             | (::Range[::Integer] range) -> ::Array[Elem]?
 

core/enumerable.rbs

@@ -528,6 +528,12 @@ module Enumerable[unchecked out Elem] : _Each[Elem]
   #
   def entries: () -> ::Array[Elem]
 
+  def enum_for: (Symbol method, *untyped, **untyped) ?{ (*untyped, **untyped) -> Integer } -> Enumerator[untyped, untyped]
+    | () ?{ () -> Integer } -> Enumerator[Elem, self]
+
+  %a{annotate:rdoc:skip}
+  alias to_enum enum_for
+
   # <!--
   #   rdoc-file=enum.c
   #   - select {|element| ... } -> array

core/module.rbs

@@ -396,7 +396,7 @@ class Module < Object
   #
   #     Hello there!
   #
-  def class_exec: [U] (*untyped args) { () -> U } -> U
+  def class_exec: [U, V] (*V args) { (*V args) [self: self] -> U } -> U
 
   # <!--
   #   rdoc-file=object.c

core/range.rbs

@@ -243,6 +243,36 @@
 class Range[out Elem] < Object
   include Enumerable[Elem]
 
+  # <!--
+  #   rdoc-file=range.c
+  #   - %(n) {|element| ... } -> self
+  #   - %(n)                  -> enumerator
+  # -->
+  # Iterates over the elements of `self`.
+  #
+  # With a block given, calls the block with selected elements of the range;
+  # returns `self`:
+  #
+  #     a = []
+  #     (1..5).%(2) {|element| a.push(element) } # => 1..5
+  #     a # => [1, 3, 5]
+  #     a = []
+  #     ('a'..'e').%(2) {|element| a.push(element) } # => "a".."e"
+  #     a # => ["a", "c", "e"]
+  #
+  # With no block given, returns an enumerator, which will be of class
+  # Enumerator::ArithmeticSequence if `self` is numeric; otherwise of class
+  # Enumerator:
+  #
+  #     e = (1..5) % 2 # => ((1..5).%(2))
+  #     e.class        # => Enumerator::ArithmeticSequence
+  #     ('a'..'e') % 2 # =>  #<Enumerator: ...>
+  #
+  # Related: Range#step.
+  #
+  def %: (Numeric | int n) -> Enumerator[Elem, self]
+    | (Numeric | int n) { (Elem element) -> void } -> self
+
   # <!--
   #   rdoc-file=range.c
   #   - self == other -> true or false

test/stdlib/Enumerable_test.rb

@@ -3,6 +3,13 @@
 class EnumerableTest < StdlibTest
   target Enumerable
 
+  def test_enum_for
+    enumerable.enum_for
+    enumerable.enum_for { 0 }
+    enumerable.enum_for(:each)
+    enumerable.enum_for(:each) { 0 }
+  end
+
   def test_find_all
     enumerable.find_all
     enumerable.find_all { |x| x.even? }
@@ -194,6 +201,13 @@ def test_each_slice
     ) do end
   end
 
+  def test_enum_for
+    assert_send_type(
+      "() ?{ () -> Integer } -> Enumerator[String, EnumerableTest2::TestEnumerable]",
+      TestEnumerable.new, :enum_for
+    )
+  end
+
   def test_find_index
     assert_send_type "() -> ::Enumerator[String, Integer?]", TestEnumerable.new,
                      :find_index

test/stdlib/Module_test.rb

@@ -130,6 +130,12 @@ def test_class_eval
                      Foo, :class_eval do nil end
   end
 
+  def test_class_exec
+    assert_send_type '(*String) { (*String) [self: Foo] -> Integer } -> Integer',
+                      Foo, :class_exec, '1', '2' do |*x| x.join.to_i end
+  end
+
+
   def test_alias_method
     mod = Module.new do
       def foo

test/stdlib/Range_test.rb

@@ -94,6 +94,11 @@ def test_min
     (1..10).min(3) { |i, j| i <=> j }
   end
 
+  def test_percent
+    (1..10).%(2)
+    ('A'...'Z').%(2) { |s| s.downcase }
+  end
+
   def test_size
     (1..10).size
     ('A'...'Z').size