Feature #17336
Updated by k0kubun (Takashi Kokubun) about 4 years ago
## Problem
When we need a monkey patch which is used only in a single file, we'd like to define a refinement and use it in the same place. The problem is that it needs deep indentation and `Module.new { ... }` which feels redundant.
```rb
class Foo
using Module.new {
refine Array do
def flat_map!(&block)
replace(flat_map(&block))
end
end
}
# ...
end
```
@tagomoris proposed an idea to reduce indentation and remove `Module.new { ... }`. This looks pretty convenient, but I want to write `do ... end`, which would make it a block of `using` here, because we almost always use `do ... end` for defining methods or modules.
```rb
module Kernel
def refined(mod, &block)
Module.new do
refine(mod, &block)
end
end
end
class Foo
using refined(Array) {
def flat_map!(&block)
replace(flat_map(&block))
end
}
# ...
end
```
## Proposal
How What about supporting this? Because `using` currently doesn't take a block, it doesn't conflict with the existing syntax.
```rb
class Foo
using refined: Array do
def flat_map!(&block)
replace(flat_map(&block))
end
end
# ...
end
```
This syntax is based on ideas of @tagomoris and @znz .