Class: Object
- Inherits:
- BasicObject
- Defined in:
- lib/ruby-try.rb
Instance Method Summary collapse
-
#try(*a, &b) ⇒ Object
public_send
does, except that if the receiver does not respond to it the call returnsnil
rather than raising an exception. -
#try!(*a, &b) ⇒ Object
Same as #try, but will raise a NoMethodError exception if the receiving is not nil and does not implement the tried method.
- #try?(*a, &b) ⇒ Boolean
Instance Method Details
#try(*a, &b) ⇒ Object
public_send
does, except that if the receiver does not respond to it the call returns nil
rather than raising an exception.
This method is defined to be able to write
@person.try(:name)
instead of
@person ? @person.name : nil
try
returns nil
when called on nil
regardless of whether it responds to the method:
nil.try(:to_i) # => nil, rather than 0
Arguments and blocks are forwarded to the method if invoked:
@posts.try(:each_slice, 2) do |a, b|
...
end
The number of arguments in the signature must match. If the object responds to the method the call is attempted and ArgumentError
is still raised otherwise.
If try
is called without arguments it yields the receiver to a given block unless it is nil
:
@person.try do |p|
...
end
Please also note that try
is defined on Object
, therefore it won’t work with instances of classes that do not have Object
among their ancestors, like direct subclasses of BasicObject
. For example, using try
with SimpleDelegator
will delegate try
to the target instead of calling it on delegator itself.
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# File 'lib/ruby-try.rb', line 41 def try(*a, &b) if a.empty? && block_given? yield self else public_send(*a, &b) if respond_to?(a.first) end end |
#try!(*a, &b) ⇒ Object
Same as #try, but will raise a NoMethodError exception if the receiving is not nil and does not implement the tried method.
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# File 'lib/ruby-try.rb', line 51 def try!(*a, &b) if a.empty? && block_given? yield self else public_send(*a, &b) end end |
#try?(*a, &b) ⇒ Boolean
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# File 'lib/ruby-try.rb', line 59 def try?(*a, &b) if a.empty? && block_given? yield self else if respond_to?(a.first) public_send(*a, &b) else nil.try?(*a, &b) end end end |