summaryrefslogtreecommitdiff
path: root/doc/syntax
diff options
context:
space:
mode:
authordrbrain <drbrain@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2013-01-16 23:36:46 +0000
committerdrbrain <drbrain@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2013-01-16 23:36:46 +0000
commit1eb9f71c3ae41182a08cd965340854f116354827 (patch)
tree6abb5b7bc584ebd726a299941569de8c89376e7a /doc/syntax
parent038c535e18549740c34d63efc3326c8e12379317 (diff)
* doc/syntax/miscellaneous.rdoc: Added documentation for alias, undef,
BEGIN, END. * doc/syntax/modules_and_classes.rdoc (Constants): Fixed unwrapped paragraph with trailing whitespace. * doc/syntax/modules_and_classes.rdoc (Scope): Added section pointing to alias and undef documentation. * doc/syntax.rdoc: Added link to miscellaneous section. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38853 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'doc/syntax')
-rw-r--r--doc/syntax/miscellaneous.rdoc61
-rw-r--r--doc/syntax/modules_and_classes.rdoc11
2 files changed, 70 insertions, 2 deletions
diff --git a/doc/syntax/miscellaneous.rdoc b/doc/syntax/miscellaneous.rdoc
new file mode 100644
index 0000000..409afc7
--- /dev/null
+++ b/doc/syntax/miscellaneous.rdoc
@@ -0,0 +1,61 @@
+= Miscellaneous Syntax
+
+== +alias+
+
+The +alias+ keyword is most frequently used to alias methods. When aliasing a
+method you can use either its name or a symbol:
+
+ alias new_name old_name
+ alias :new_name :old_name
+
+For methods, Module#alias_method can often be used instead of +alias+.
+
+You can also use +alias+ to alias global variables:
+
+ $old = 0
+
+ alias $new $old
+
+ p $new # prints 0
+
+You may use +alias+ in any scope.
+
+== +undef+
+
+The +undef+ keyword prevents the current class from responding to calls to the
+named methods.
+
+ undef my_method
+
+You may use symbols instead of method names:
+
+ undef :my_method
+
+You may undef multiple methods:
+
+ undef method1, method2
+
+You may use +undef+ in any scope. See also Module#undef_method
+
+== +BEGIN+ and +END+
+
++BEGIN+ defines a block that is run before any other code in the current file.
+It is typically used in one-liners with <code>ruby -e</code>. Similarly +END+
+defines a block that is run after any other code.
+
++BEGIN+ must appear at top-level and +END+ will issue a warning when you use it
+inside a method.
+
+Here is an example:
+
+ BEGIN {
+ count = 0
+ }
+
+You must use <code>{</code> and <code>}</code> you may not use +do+ and +end+.
+
+Here is an example one-liner that adds numbers from standard input or any files
+in the argument list:
+
+ ruby -ne 'BEGIN { count = 0 }; END { puts count }; count += gets.to_i'
+
diff --git a/doc/syntax/modules_and_classes.rdoc b/doc/syntax/modules_and_classes.rdoc
index 2c8f532..f4ab1ea 100644
--- a/doc/syntax/modules_and_classes.rdoc
+++ b/doc/syntax/modules_and_classes.rdoc
@@ -93,8 +93,9 @@ nesting:
end
end
-However, if you use <code>::</code> to define <code>A::B</code> without nesting
-it inside +A+ a NameError exception will be raised because the nesting does not include +A+:
+However, if you use <code>::</code> to define <code>A::B</code> without
+nesting it inside +A+ a NameError exception will be raised because the nesting
+does not include +A+:
module A
Z = 1
@@ -193,6 +194,12 @@ The third visibility is +private+. A private method may not be called with a
receiver, not even +self+. If a private method is called with a receiver a
NoMethodError will be raised.
+=== +alias+ and +undef+
+
+You may also alias or undefine methods, but these operations are not
+restricted to modules or classes. See the {miscellaneous syntax
+section}[rdoc-ref:syntax/miscellaneous.rdoc] for documentation.
+
= Classes
Every class is also a module, but unlike modules a class may not be mixed-in to