X-Git-Url: http://nitlanguage.org

diff --git a/lib/standard/kernel.nit b/lib/standard/kernel.nit
index a179e9a..dfff892 100644
--- a/lib/standard/kernel.nit
+++ b/lib/standard/kernel.nit
@@ -17,10 +17,6 @@ module kernel
 
 import end # Mark this module is a top level one. (must be only one)
 
-`{
-#include <errno.h>
-`}
-
 ###############################################################################
 # System Classes                                                              #
 ###############################################################################
@@ -66,13 +62,13 @@ interface Object
 	fun is_same_instance(other: nullable Object): Bool is intern
 
 	# Have `self` and `other` the same value?
-	##
+	#
 	# The exact meaning of "same value" is let to the subclasses.
 	# Implicitly, the default implementation, is `is_same_instance`
 	fun ==(other: nullable Object): Bool do return self.is_same_instance(other)
 
 	# Have `self` and `other` different values?
-	##
+	#
 	# != is equivalent with "not ==".
 	fun !=(other: nullable Object): Bool do return not (self == other)
 
@@ -93,7 +89,7 @@ interface Object
 
 	# The hash code of the object.
 	# Assuming that a == b -> a.hash == b.hash
-	##
+	#
 	# Without redefinition, it is based on the `object_id` of the instance.
 	fun hash: Int do return object_id / 8
 end
@@ -111,9 +107,7 @@ class Sys
 	fun run do main
 
 	# Number of the last error
-	fun errno: Int is extern `{
-		return errno;
-	`}
+	fun errno: Int is extern "sys_errno"
 end
 
 # Quit the program with a specific return code
@@ -226,6 +220,25 @@ interface Discrete
 	end
 end
 
+# Something that can be cloned
+#
+# This interface introduces the `clone` method used to duplicate an instance
+# Its specific semantic is let to the subclasses.
+interface Cloneable
+	# Duplicate `self`
+	#
+	# The specific semantic of this method is let to the subclasses;
+	# Especially, if (and how) attributes are cloned (depth vs. shallow).
+	#
+	# As a rule of thumb, the principle of least astonishment should
+	# be used to guide the semantic.
+	#
+	# Note that as the returned clone depends on the semantic,
+	# the `==` method, if redefined, should ensure the equality
+	# between an object and its clone.
+	fun clone: SELF is abstract
+end
+
 # A numeric value supporting mathematical operations
 interface Numeric
 	super Comparable
@@ -283,8 +296,10 @@ end
 
 # Native Booleans.
 # `true` and `false` are the only instances.
+#
 # Boolean are manipulated trough three special operators:
-#	 `and`, `or`, `not`.
+# `and`, `or`, `not`.
+#
 # Booleans are mainly used by conditional statement and loops.
 universal Bool
 	redef fun object_id is intern
@@ -414,6 +429,13 @@ universal Int
 	redef fun -(i) is intern
 	redef fun *(i) is intern
 	redef fun /(i) is intern
+
+	# Modulo of `self` with `i`.
+	#
+	# Finds the remainder of division of `self` by `i`.
+	#
+	#     assert 5 % 2			== 1
+	#     assert 10 % 2			== 0
 	fun %(i: Int): Int is intern
 
 	redef fun zero do return 0
@@ -482,8 +504,8 @@ universal Int
 
 	# The character whose ASCII value is `self`.
 	#
-	#      assert 65.ascii   == 'A'
-	#      assert 10.ascii   == '\n'
+	#     assert 65.ascii   == 'A'
+	#     assert 10.ascii   == '\n'
 	fun ascii: Char is intern
 
 	# Number of digits of an integer in base `b` (plus one if negative)
@@ -690,6 +712,22 @@ universal Char
 	do
 		return is_lower or is_upper
 	end
+
+	# Is self a whitespace character?
+	#
+	# These correspond to the "Other" and "Separator" groups of the Unicode.
+	#
+	# In the ASCII encoding, this is those <= to space (0x20) plus delete (0x7F).
+	#
+	#     assert 'A'.is_whitespace  == false
+	#     assert ','.is_whitespace  == false
+	#     assert ' '.is_whitespace  == true
+	#     assert '\t'.is_whitespace == true
+	fun is_whitespace: Bool
+	do
+		var i = ascii
+		return i <= 0x20 or i == 0x7F
+	end
 end
 
 # Pointer classes are used to manipulate extern C structures.
@@ -698,5 +736,5 @@ extern class Pointer
 	fun address_is_null: Bool is extern "address_is_null"
 
 	# Free the memory pointed by this pointer
-	fun free `{ free(recv); `}
+	fun free is extern "free"
 end