Updated Kernel conversion methods

core/kernel.rbs

@@ -403,12 +403,10 @@ module Kernel : BasicObject
   #
   #     Array(:foo)             # => [:foo]
   #
-  def self?.Array: (NilClass x) -> [ ]
-                 | [T] (::Array[T] x) -> ::Array[T]
-                 | [T] (::Range[T] x) -> ::Array[T]
-                 | [T] (_Each[T] x) -> ::Array[T]
-                 | [K, V] (::Hash[K, V] x) -> ::Array[[ K, V ]]
-                 | [T] (T x) -> ::Array[T]
+  def self?.Array: (nil) -> []
+                 | [T] (Array[T] ary) -> Array[T]
+                 | [T] (_ToAry[T] | _ToA[T] array_like) -> Array[T]
+                 | [T] (T ele) -> [T]
 
   # <!--
   #   rdoc-file=complex.c
@@ -446,8 +444,11 @@ module Kernel : BasicObject
   #
   # See String#to_c.
   #
-  def self?.Complex: (Numeric | String x, ?Numeric | String y, ?exception: bool exception) -> Complex
-
+  def self?.Complex: (_ToC complex_like, ?exception: true) -> Complex
+                   | (_ToC complex_like, exception: bool) -> Complex?
+                   | (Numeric | String real, ?Numeric | String imag, ?exception: true) -> Complex
+                   | (Numeric | String real, ?Numeric | String imag, exception: bool) -> Complex?
+                   | (untyped, ?untyped, exception: false) -> nil
   # <!--
   #   rdoc-file=kernel.rb
   #   - Float(arg, exception: true)    -> float or nil
@@ -464,8 +465,9 @@ module Kernel : BasicObject
   #     Float(nil)               #=> TypeError: can't convert nil into Float
   #     Float("123.0_badstring", exception: false)  #=> nil
   #
-  def self?.Float: (Numeric | String x, ?exception: bool exception) -> Float
-
+  def self?.Float: (_ToF float_like, ?exception: true) -> Float
+                 | (_ToF float_like, exception: bool) -> Float?
+                 | (untyped, exception: false) -> nil
   # <!--
   #   rdoc-file=object.c
   #   - Hash(object) -> object or new_hash
@@ -488,7 +490,8 @@ module Kernel : BasicObject
   #     Hash(nil)              # => {}
   #     Hash([])               # => {}
   #
-  def self?.Hash: [K, V] (Object x) -> ::Hash[K, V]
+  def self?.Hash: [K, V] (nil | [] _empty) -> Hash[K, V]
+                | [K, V] (_ToHash[K, V] hash_like) -> Hash[K, V]
 
   # <!--
   #   rdoc-file=object.c
@@ -574,9 +577,11 @@ module Kernel : BasicObject
   # With `exception` given as `false`, an exception of any kind is suppressed and
   # `nil` is returned.
   #
-  def self?.Integer: (Numeric | String arg, ?exception: bool exception) -> Integer
-                   | (String arg, ?Integer base, ?exception: bool exception) -> Integer
-
+  def self?.Integer: (_ToInt | _ToI int_like, ?exception: true) -> Integer
+                   | (_ToInt | _ToI int_like, exception: bool) -> Integer?
+                   | (string str, ?int base, ?exception: true) -> Integer
+                   | (string str, ?int base, exception: bool) -> Integer?
+                   | (untyped, ?untyped, exception: false) -> nil
   # <!--
   #   rdoc-file=rational.c
   #   - Rational(x, y, exception: true)  ->  rational or nil
@@ -614,7 +619,17 @@ module Kernel : BasicObject
   #
   # See also String#to_r.
   #
-  def self?.Rational: (Numeric | String | Object x, ?Numeric | String y, ?exception: bool exception) -> Rational
+  def self?.Rational: (_ToInt | _ToR rational_like, ?exception: true) -> Rational
+                    | (_ToInt | _ToR rational_like, exception: bool) -> Rational?
+                    | (_ToInt | _ToR numer, ?_ToInt | _ToR denom, ?exception: true) -> Rational
+                    | (_ToInt | _ToR numer, ?_ToInt | _ToR denom, exception: bool) -> Rational?
+                    | [T] (Numeric&_RationalDiv[T] numer, Numeric denom, ?exception: bool) -> T
+                    | [T < Numeric] (T value, 1, ?exception: bool) -> T
+                    | (untyped, ?untyped, exception: false) -> nil
+
+  interface _RationalDiv[T]
+    def /: (Numeric) -> T
+  end
 
   # <!--
   #   rdoc-file=object.c
@@ -630,7 +645,7 @@ module Kernel : BasicObject
   #
   # Raises `TypeError` if `object` cannot be converted to a string.
   #
-  def self?.String: (_ToStr | _ToS x) -> String
+  def self?.String: (string | _ToS string_like) -> String
 
   # <!--
   #   rdoc-file=eval.c

test/stdlib/Kernel_test.rb

@@ -285,49 +285,125 @@ def test_untaint
 
   def test_Array
     Array(nil)
-    Array('foo')
-    Array(['foo'])
-    Array(1..4)
-    Array({foo: 1})
+
+    # We add the `.first.whatever` tests to make sure that we're being returned the right type.
+    Array([1,2,3]).first.even?
+    Array(ToArray.new(1,2)).first.even?
+    Array(ToA.new(1,2)).first.even?
+    Array(1..4).first.even?
+    Array({34 => 'hello'}).first.first.even?
+
+    Array('foo').first.upcase
+    Array(['foo']).first.upcase
   end
 
   def test_Complex
-    Complex(1.3)
-    Complex(42)
-    Complex(1, 2)
-    Complex('42', exception: true)
+    Complex(1.3).real?
+    Complex(1.3, exception: true).real?
+    Complex(1.3, exception: false)&.real?
+    Complex(1.3, exception: $VERBOSE)&.real? # `$VERBOSE` is an undecidable-at-compile-time bool.
+
+    Complex('1+2i')
+    Complex(1r)
+    Complex(Class.new(Numeric).new)
+
+    # The `Kernel#Complex` function is the only place in the entire stdlib that uses `.to_c`
+    def (obj = BasicObject.new).to_c
+      1+3i
+    end
+    Complex(obj)
+
+    Complex(1.3, '1i')
+    Complex(Class.new(Numeric).new, "1")
   end
 
   def test_Float
-    Float(42)
+    Float(42).infinite?
+    Float(42, exception: true).real?
+    Float(42, exception: false)&.real?
+    Float(42, exception: $VERBOSE)&.real? # `$VERBOSE` is an undecidable-at-compile-time bool.
+
     Float(1.4)
     Float('1.4')
-    Float('1.4', exception: true)
+    Float(ToF.new)
   end
 
   def test_Hash
     Hash(nil)
     Hash([])
+
     Hash({key: 1})
+    Hash(ToHash.new)
   end
 
   def test_Integer
-    Integer(42)
+    Integer(42).even?
+    Integer(42, exception: true).even?
+    Integer(42, exception: false)&.even?
+    Integer(42, exception: $VERBOSE)&.even? # `$VERBOSE` is an undecidable-at-compile-time bool.
+
     Integer(2.3)
-    Integer('2', exception: true)
-    Integer('11', 2, exception: true)
+    Integer(ToInt.new)
+    Integer(ToI.new)
+
+    Integer('2').even?
+    Integer('2', exception: true).even?
+    Integer('2', exception: false)&.even?
+    Integer('2', exception: $VERBOSE)&.even? # `$VERBOSE` is an undecidable-at-compile-time bool.
+
+    Integer('11', 2)
+    Integer(ToStr.new('11'), ToInt.new(12))
+  end
+
+  # These two classes are required to for `test_Rational`, and the `Class.new(Numeric)` construct
+  # doesn't type check them properly (yet.)
+  class Rational_RationalDiv < Numeric
+    def /(numeric) "Hello!" end
+  end
+  class Rational_OneCase < Numeric
+    def __unique_method_name__; 34 end
   end
 
   def test_Rational
-    Rational(42)
+    Rational(42).integer?
+    Rational(42, exception: true).integer?
+    Rational(42, exception: false)&.integer?
+    Rational(42, exception: $VERBOSE)&.integer? # `$VERBOSE` is an undecidable-at-compile-time bool.
+
+    def (test_rational = BasicObject.new).to_r
+      1r
+    end
+
+    Rational(ToInt.new)
+    Rational(test_rational)
+
     Rational(42.0, 3)
     Rational('42.0', 3, exception: true)
+    Rational(ToInt.new, test_rational)
+    Rational(test_rational, ToInt.new, exception: false)
+
+    rational_div = Rational_RationalDiv.new
+    # `Rational` ignores `exception:` in the `_RationalDiv` variant.
+    Rational(rational_div, Class.new(Numeric).new).upcase
+    Rational(rational_div, Class.new(Numeric).new, exception: true).upcase
+    Rational(rational_div, Class.new(Numeric).new, exception: false).upcase
+    Rational(rational_div, Class.new(Numeric).new, exception: $VERBOSE).upcase
+
+    one_case = Rational_OneCase.new
+    # `Rational` also ignores `exception:` in the `(Numeric, 1)` variant.
+    Rational(one_case, 1).__unique_method_name__
+    Rational(one_case, 1, exception: true).__unique_method_name__
+    Rational(one_case, 1, exception: false).__unique_method_name__
+    Rational(one_case, 1, exception: $VERBOSE).__unique_method_name__
   end
 
   def test_String
     String('foo')
     String([])
     String(nil)
+
+    String(ToS.new)
+    String(ToStr.new)
   end
 
   def test___callee__

test/stdlib/test_helper.rb

@@ -392,6 +392,16 @@ def allows_error(*errors)
   include VersionHelper
 end
 
+class ToI
+  def initialize(value = 3)
+    @value = value
+  end
+
+  def to_i
+    @value
+  end
+end
+
 class ToInt
   def initialize(value = 3)
     @value = value
@@ -432,6 +442,16 @@ def to_s
   end
 end
 
+class ToA
+  def initialize(*args)
+    @args = args
+  end
+
+  def to_a
+    @args
+  end
+end
+
 class ToArray
   def initialize(*args)
     @args = args
@@ -440,6 +460,16 @@ def initialize(*args)
   def to_ary
     @args
   end
+end 
+
+class ToHash
+  def initialize(hash = { 'hello' => 'world' })
+    @hash = hash
+  end
+
+  def to_hash
+    @hash
+  end
 end
 
 class ToPath