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authorJeremy Evans <code@jeremyevans.net>2021-11-19 09:38:22 -0800
committerJeremy Evans <code@jeremyevans.net>2021-12-30 14:37:42 -0800
commitf53dfab95c30e222f67e610234f63d3e9189234d (patch)
tree83a9c1d49e3f96e36f75721d0ca1437aa2b56677 /doc
parent2d2ee338f3427d39d9977c77b09e5d335b6e362b (diff)
Add support for anonymous rest and keyword rest argument forwarding
This allows for the following syntax: ```ruby def foo(*) bar(*) end def baz(**) quux(**) end ``` This is a natural addition after the introduction of anonymous block forwarding. Anonymous rest and keyword rest arguments were already supported in method parameters, this just allows them to be used as arguments to other methods. The same advantages of anonymous block forwarding apply to rest and keyword rest argument forwarding. This has some minor changes to #parameters output. Now, instead of `[:rest], [:keyrest]`, you get `[:rest, :*], [:keyrest, :**]`. These were already used for `...` forwarding, so I think it makes it more consistent to include them in other cases. If we want to use `[:rest], [:keyrest]` in both cases, that is also possible. I don't think the previous behavior of `[:rest], [:keyrest]` in the non-... case and `[:rest, :*], [:keyrest, :**]` in the ... case makes sense, but if we did want that behavior, we'll have to make more substantial changes, such as using a different ID in the ... forwarding case. Implements [Feature #18351]
Notes
Notes: Merged: https://github.com/ruby/ruby/pull/5148
Diffstat (limited to 'doc')
-rw-r--r--doc/syntax/methods.rdoc14
1 files changed, 14 insertions, 0 deletions
diff --git a/doc/syntax/methods.rdoc b/doc/syntax/methods.rdoc
index 2bb350def1..8dafa6bb0c 100644
--- a/doc/syntax/methods.rdoc
+++ b/doc/syntax/methods.rdoc
@@ -441,6 +441,13 @@ Also, note that a bare <code>*</code> can be used to ignore arguments:
def ignore_arguments(*)
end
+You can also use a bare <code>*</code> when calling a method to pass the
+arguments directly to another method:
+
+ def delegate_arguments(*)
+ other_method(*)
+ end
+
=== Keyword Arguments
Keyword arguments are similar to positional arguments with default values:
@@ -481,6 +488,13 @@ Also, note that <code>**</code> can be used to ignore keyword arguments:
def ignore_keywords(**)
end
+You can also use <code>**</code> when calling a method to delegate
+keyword arguments to another method:
+
+ def delegate_keywords(**)
+ other_method(**)
+ end
+
To mark a method as accepting keywords, but not actually accepting
keywords, you can use the <code>**nil</code>: