Let puts and other printing methods return nil

Ary Borenszweig · Ary Borenszweig · commit ba5c2b0828cf · 2017-01-05T11:14:17.000-03:00
diff --git a/src/array.cr b/src/array.cr
@@ -94,9 +94,9 @@ class Array(T)
   # Array.new(3, 'a') # => ['a', 'a', 'a']
   #
   # ary = Array.new(3, [1])
-  # puts ary # => [[1], [1], [1]]
+  # ary # => [[1], [1], [1]]
   # ary[0][0] = 2
-  # puts ary # => [[2], [2], [2]]
+  # ary # => [[2], [2], [2]]
   # ```
   def initialize(size : Int, value : T)
     if size < 0
@@ -120,9 +120,9 @@ class Array(T)
   # Array.new(3) { |i| (i + 1) ** 2 } # => [1, 4, 9]
   #
   # ary = Array.new(3) { [1] }
-  # puts ary # => [[1], [1], [1]]
+  # ary # => [[1], [1], [1]]
   # ary[0][0] = 2
-  # puts ary # => [[2], [1], [1]]
+  # ary # => [[2], [1], [1]]
   # ```
   def self.new(size : Int, &block : Int32 -> T)
     Array(T).build(size) do |buffer|
@@ -521,12 +521,12 @@ class Array(T)
   # ary = [[1, 2], [3, 4]]
   # ary2 = ary.clone
   # ary[0][0] = 5
-  # puts ary  # => [[5, 2], [3, 4]]
-  # puts ary2 # => [[1, 2], [3, 4]]
+  # ary  # => [[5, 2], [3, 4]]
+  # ary2 # => [[1, 2], [3, 4]]
   #
   # ary2 << [7, 8]
-  # puts ary  # => [[5, 2], [3, 4]]
-  # puts ary2 # => [[1, 2], [3, 4], [7, 8]]
+  # ary  # => [[5, 2], [3, 4]]
+  # ary2 # => [[1, 2], [3, 4], [7, 8]]
   # ```
   def clone
     Array(T).new(size) { |i| @buffer[i].clone.as(T) }
@@ -674,12 +674,12 @@ class Array(T)
   # ary = [[1, 2], [3, 4]]
   # ary2 = ary.dup
   # ary[0][0] = 5
-  # puts ary  # => [[5, 2], [3, 4]]
-  # puts ary2 # => [[5, 2], [3, 4]]
+  # ary  # => [[5, 2], [3, 4]]
+  # ary2 # => [[5, 2], [3, 4]]
   #
   # ary2 << [7, 8]
-  # puts ary  # => [[5, 2], [3, 4]]
-  # puts ary2 # => [[5, 2], [3, 4], [7, 8]]
+  # ary  # => [[5, 2], [3, 4]]
+  # ary2 # => [[5, 2], [3, 4], [7, 8]]
   # ```
   def dup
     Array(T).build(@capacity) do |buffer|
diff --git a/src/big/big_int.cr b/src/big/big_int.cr
@@ -274,7 +274,7 @@ struct BigInt < Int
   # Returns a string representation of self.
   #
   # ```
-  # puts BigInt.new("123456789101101987654321").to_s # => 123456789101101987654321
+  # BigInt.new("123456789101101987654321").to_s # => 123456789101101987654321
   # ```
   def to_s
     String.new(to_cstr)
@@ -289,9 +289,9 @@ struct BigInt < Int
   # Returns a string containing the representation of big radix base (2 through 36).
   #
   # ```
-  # puts BigInt.new("123456789101101987654321").to_s(8)  # => 32111154373025463465765261
-  # puts BigInt.new("123456789101101987654321").to_s(16) # => 1a249b1f61599cd7eab1
-  # puts BigInt.new("123456789101101987654321").to_s(36) # => k3qmt029k48nmpd
+  # BigInt.new("123456789101101987654321").to_s(8)  # => 32111154373025463465765261
+  # BigInt.new("123456789101101987654321").to_s(16) # => 1a249b1f61599cd7eab1
+  # BigInt.new("123456789101101987654321").to_s(36) # => k3qmt029k48nmpd
   # ```
   def to_s(base : Int)
     raise "Invalid base #{base}" unless 2 <= base <= 36
diff --git a/src/bit_array.cr b/src/bit_array.cr
@@ -89,7 +89,7 @@ struct BitArray
   #
   # ```
   # ba = BitArray.new(5)
-  # puts ba.to_s # => "BitArray[00000]"
+  # ba.to_s # => "BitArray[00000]"
   # ```
   def to_s(io : IO)
     io << "BitArray["
diff --git a/src/enum.cr b/src/enum.cr
@@ -44,14 +44,14 @@
 # An enum can be created from an integer:
 #
 # ```
-# puts Color.new(1) # => "Green"
+# Color.new(1).to_s # => "Green"
 # ```
 #
 # Values that don't correspond to an enum's constants are allowed: the value will still be of type Color,
 # but when printed you will get the underlying value:
 #
 # ```
-# puts Color.new(10) # => "10"
+# Color.new(10).to_s # => "10"
 # ```
 #
 # This method is mainly intended to convert integers from C to enums in Crystal.
diff --git a/src/kernel.cr b/src/kernel.cr
@@ -44,21 +44,20 @@ end
 # Prints objects to STDOUT and then invokes `STDOUT.flush`.
 #
 # See also: `IO#print`.
-def print(*objects : _)
+def print(*objects : _) : Nil
   STDOUT.print *objects
   STDOUT.flush
-  nil
 end
 
 # Prints a formatted string to STDOUT.
 #
 # See also: `IO#printf`.
-def printf(format_string, *args)
+def printf(format_string, *args) : Nil
   printf format_string, args
 end
 
 # ditto
-def printf(format_string, args : Array | Tuple)
+def printf(format_string, args : Array | Tuple) : Nil
   STDOUT.printf format_string, args
 end
 
@@ -79,40 +78,38 @@ end
 # Prints objects to STDOUT, each followed by a newline.
 #
 # See also: `IO#puts`.
-def puts(*objects)
+def puts(*objects) : Nil
   STDOUT.puts *objects
 end
 
 # Pretty prints *object* to STDOUT followed
-# by a newline. Returns *object*.
+# by a newline.
 #
 # See also: `Object#pretty_print(pp)`.
-def p(object)
+def p(object) : Nil
   PrettyPrint.format(object, STDOUT, 79)
   puts
-  object
 end
 
 # Pretty prints each object in *objects* to STDOUT, followed
-# by a newline. Returns *objects*.
+# by a newline.
 #
 # See also: `Object#pretty_print(pp)`.
-def p(*objects)
+def p(*objects) : Nil
   objects.each do |obj|
     p obj
   end
-  objects
 end
 
 # Pretty prints each object in *objects* to STDOUT, followed
-# by a newline. Returns *objects*.
+# by a newline.
 #
 # ```
-# p foo: 23, bar: 42 # => {foo: 23, bar: 42}
+# p foo: 23, bar: 42 # prints "{foo: 23, bar: 42}"
 # ```
 #
 # See `Object#pretty_print(pp)`
-def p(**objects)
+def p(**objects) : Nil
   p(objects)
 end
 
@@ -157,15 +154,15 @@ end
 # ```text
 # goodbye cruel world
 # ```
-def at_exit(&handler : Int32 ->)
+def at_exit(&handler : Int32 ->) : Nil
   AtExitHandlers.add(handler)
 end
 
 # Terminates execution immediately, returning the given status code
 # to the invoking environment.
 #
 # Registered `at_exit` procs are executed.
-def exit(status = 0)
+def exit(status = 0) : NoReturn
   AtExitHandlers.run status
   STDOUT.flush
   STDERR.flush
@@ -174,7 +171,7 @@ end
 
 # Terminates execution immediately, printing *message* to STDERR and
 # then calling `exit(status)`.
-def abort(message, status = 1)
+def abort(message, status = 1) : NoReturn
   STDERR.puts message if message
   exit status
 end
diff --git a/src/pointer.cr b/src/pointer.cr
@@ -18,7 +18,7 @@ require "c/string"
 # x = 1
 # ptr = pointerof(x)
 # ptr.value = 2
-# puts x # => 2
+# x # => 2
 # ```
 #
 # Note that a pointer is *falsey* if it's null (if it's address is zero).

Original file line number	Diff line number	Diff line change
`@@ -89,7 +89,7 @@ struct BitArray`
`89`	`89`	`#`
`90`	`90`	# ```
`91`	`91`	`# ba = BitArray.new(5)`
`92`		`- # puts ba.to_s # => "BitArray[00000]"`
	`92`	`+ # ba.to_s # => "BitArray[00000]"`
`93`	`93`	# ```
`94`	`94`	`def to_s(io : IO)`
`95`	`95`	`io << "BitArray["`
Original file line number	Diff line number	Diff line change
`@@ -44,14 +44,14 @@`
`44`	`44`	`# An enum can be created from an integer:`
`45`	`45`	`#`
`46`	`46`	# ```
`47`		`-# puts Color.new(1) # => "Green"`
	`47`	`+# Color.new(1).to_s # => "Green"`
`48`	`48`	# ```
`49`	`49`	`#`
`50`	`50`	`# Values that don't correspond to an enum's constants are allowed: the value will still be of type Color,`
`51`	`51`	`# but when printed you will get the underlying value:`
`52`	`52`	`#`
`53`	`53`	# ```
`54`		`-# puts Color.new(10) # => "10"`
	`54`	`+# Color.new(10).to_s # => "10"`
`55`	`55`	# ```
`56`	`56`	`#`
`57`	`57`	`# This method is mainly intended to convert integers from C to enums in Crystal.`
Original file line number	Diff line number	Diff line change
`@@ -18,7 +18,7 @@ require "c/string"`
`18`	`18`	`# x = 1`
`19`	`19`	`# ptr = pointerof(x)`
`20`	`20`	`# ptr.value = 2`
`21`		`-# puts x # => 2`
	`21`	`+# x # => 2`
`22`	`22`	# ```
`23`	`23`	`#`
`24`	`24`	`# Note that a pointer is falsey if it's null (if it's address is zero).`