diff options
author | Burdette Lamar <BurdetteLamar@Yahoo.com> | 2021-09-23 17:21:40 -0500 |
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committer | GitHub <noreply@github.com> | 2021-09-23 17:21:40 -0500 |
commit | b38d2bf1182081df7cb09538bb4b23e89a416dfb (patch) | |
tree | 315ae45d7f45fa3e2ac06e56b0631f63ef511804 /struct.c | |
parent | edb34e35639b1446cf3a860f9a839e910297387a (diff) |
Enhance RDoc for Struct (#4885)
Treats #members and ::new.
Notes
Notes:
Merged-By: BurdetteLamar <BurdetteLamar@Yahoo.com>
Diffstat (limited to 'struct.c')
-rw-r--r-- | struct.c | 170 |
1 files changed, 108 insertions, 62 deletions
@@ -200,13 +200,12 @@ rb_struct_s_members_m(VALUE klass) /* * call-seq: - * struct.members -> array + * members -> array_of_symbols * - * Returns the struct members as an array of symbols: + * Returns the member names from +self+ as an array: * * Customer = Struct.new(:name, :address, :zip) - * joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) - * joe.members #=> [:name, :address, :zip] + * Customer.new.members # => [:name, :address, :zip] */ static VALUE @@ -510,65 +509,112 @@ rb_struct_define_under(VALUE outer, const char *name, ...) /* * call-seq: - * Struct.new([class_name] [, member_name]+) -> StructClass - * Struct.new([class_name] [, member_name]+, keyword_init: true) -> StructClass - * Struct.new([class_name] [, member_name]+) {|StructClass| block } -> StructClass - * StructClass.new(value, ...) -> object - * StructClass[value, ...] -> object - * - * The first two forms are used to create a new Struct subclass +class_name+ - * that can contain a value for each +member_name+. This subclass can be - * used to create instances of the structure like any other Class. - * - * If the +class_name+ is omitted an anonymous structure class will be - * created. Otherwise, the name of this struct will appear as a constant in - * class Struct, so it must be unique for all Structs in the system and - * must start with a capital letter. Assigning a structure class to a - * constant also gives the class the name of the constant. - * - * # Create a structure with a name under Struct - * Struct.new("Customer", :name, :address) - * #=> Struct::Customer - * Struct::Customer.new("Dave", "123 Main") - * #=> #<struct Struct::Customer name="Dave", address="123 Main"> - * - * # Create a structure named by its constant - * Customer = Struct.new(:name, :address) - * #=> Customer - * Customer.new("Dave", "123 Main") - * #=> #<struct Customer name="Dave", address="123 Main"> - * - * If the optional +keyword_init+ keyword argument is set to +true+, - * .new takes keyword arguments instead of normal arguments. - * - * Customer = Struct.new(:name, :address, keyword_init: true) - * Customer.new(name: "Dave", address: "123 Main") - * #=> #<struct Customer name="Dave", address="123 Main"> - * - * If a block is given it will be evaluated in the context of - * +StructClass+, passing the created class as a parameter: + * Struct.new(*member_names, keyword_init: false){|Struct_subclass| ... } -> Struct_subclass + * Struct.new(class_name, *member_names, keyword_init: false){|Struct_subclass| ... } -> Struct_subclass + * Struct_subclass.new(*member_names) -> Struct_subclass_instance + * Struct_subclass.new(**member_names) -> Struct_subclass_instance + * + * <tt>Struct.new</tt> returns a new subclass of +Struct+. The new subclass: + * + * - May be anonymous, or may have the name given by +class_name+. + * - May have members as given by +member_names+. + * - May have initialization via ordinary arguments (the default) + * or via keyword arguments (if <tt>keyword_init: true</tt> is given). + * + * The new subclass has its own method <tt>::new</tt>; thus: + * + * Foo = Struct.new('Foo', :foo, :bar) # => Struct::Foo + * f = Foo.new(0, 1) # => #<struct Struct::Foo foo=0, bar=1> + * + * <b>\Class Name</b> + * + * With string argument +class_name+, + * returns a new subclass of +Struct+ named <tt>Struct::<em>class_name</em></tt>: + * + * Foo = Struct.new('Foo', :foo, :bar) # => Struct::Foo + * Foo.name # => "Struct::Foo" + * Foo.superclass # => Struct + * + * Without string argument +class_name+, + * returns a new anonymous subclass of +Struct+: + * + * Struct.new(:foo, :bar).name # => nil + * + * <b>Block</b> + * + * With a block given, the created subclass is yielded to the block: + * + * Customer = Struct.new('Customer', :name, :address) do |new_class| + * p "The new subclass is #{new_class}" + * def greeting + * "Hello #{name} at #{address}" + * end + * end # => Struct::Customer + * dave = Customer.new('Dave', '123 Main') + * dave # => #<struct Struct::Customer name="Dave", address="123 Main"> + * dave.greeting # => "Hello Dave at 123 Main" + * + * Output, from <tt>Struct.new</tt>: + * + * "The new subclass is Struct::Customer" + * + * <b>Member Names</b> + * + * \Symbol arguments +member_names+ + * determines the members of the new subclass: + * + * Struct.new(:foo, :bar).members # => [:foo, :bar] + * Struct.new('Foo', :foo, :bar).members # => [:foo, :bar] + * + * The new subclass has instance methods corresponding to +member_names+: + * + * Foo = Struct.new('Foo', :foo, :bar) + * Foo.instance_methods(false) # => [:foo, :bar, :foo=, :bar=] + * f = Foo.new # => #<struct Struct::Foo foo=nil, bar=nil> + * f.foo # => nil + * f.foo = 0 # => 0 + * f.bar # => nil + * f.bar = 1 # => 1 + * f # => #<struct Struct::Foo foo=0, bar=1> + * + * <b>Singleton Methods</b> + * + * A subclass returned by Struct.new has these singleton methods: + * + * - \Method <tt>::new </tt> creates an instance of the subclass: + * + * Foo.new # => #<struct Struct::Foo foo=nil, bar=nil> + * Foo.new(0) # => #<struct Struct::Foo foo=0, bar=nil> + * Foo.new(0, 1) # => #<struct Struct::Foo foo=0, bar=1> + * Foo.new(0, 1, 2) # Raises ArgumentError: struct size differs + * + * \Method <tt>::[]</tt> is an alias for method <tt>::new</tt>. + * + * - \Method <tt>:inspect</tt> returns a string representation of the subclass: + * + * Foo.inspect + * # => "Struct::Foo" + * + * - \Method <tt>::members</tt> returns an array of the member names: + * + * Foo.members # => [:foo, :bar] + * + * <b>Keyword Argument</b> + * + * By default, the arguments for initializing an instance of the new subclass + * are ordinary arguments (not keyword arguments). + * With optional keyword argument <tt>keyword_init: true</tt>, + * the new subclass is initialized with keyword arguments: + * + * # Without keyword_init: true. + * Foo = Struct.new('Foo', :foo, :bar) + * Foo # => Struct::Foo + * Foo.new(0, 1) # => #<struct Struct::Foo foo=0, bar=1> + * # With keyword_init: true. + * Bar = Struct.new(:foo, :bar, keyword_init: true) + * Bar # => # => Bar(keyword_init: true) + * Bar.new(bar: 1, foo: 0) # => #<struct Bar foo=0, bar=1> * - * Customer = Struct.new(:name, :address) do - * def greeting - * "Hello #{name}!" - * end - * end - * Customer.new("Dave", "123 Main").greeting #=> "Hello Dave!" - * - * This is the recommended way to customize a struct. Subclassing an - * anonymous struct creates an extra anonymous class that will never be used. - * - * The last two forms create a new instance of a struct subclass. The number - * of +value+ parameters must be less than or equal to the number of - * attributes defined for the structure. Unset parameters default to +nil+. - * Passing more parameters than number of attributes will raise - * an ArgumentError. - * - * Customer = Struct.new(:name, :address) - * Customer.new("Dave", "123 Main") - * #=> #<struct Customer name="Dave", address="123 Main"> - * Customer["Dave"] - * #=> #<struct Customer name="Dave", address=nil> */ static VALUE |