Make the argument of `Kernel#catch` optional as Ruby does
Also implement the following changes.
* Add tests
* Use `Object#equal?` to compare tags for Ruby compatibility
* Use `attr_reader`
MODIFY
mrbgems/mruby-catch/mrblib/catch.rb
mrbgems/mruby-catch/mrblib/catch.rb
class ThrowCatchJump < Exception
+ attr_reader :_tag, :_val
def initialize(tag, val)
- @tag = tag
- @val = val
+ @_tag = tag
+ @_val = val
super("uncaught throw #{tag.inspect}")
end
- def _tag
- @tag
- end
- def _val
- @val
- end
end
module Kernel
- def catch(tag, &block)
+ def catch(tag=Object.new, &block)
block.call(tag)
rescue ThrowCatchJump => e
- unless e._tag == tag
+ unless e._tag.equal?(tag)
raise e
end
return e._val

ADD
mrbgems/mruby-catch/test/catch.rb
+assert "return throw value" do
+ val = ["val"]
+ result = catch :foo do
+ loop do
+ loop do
+ throw :foo, val
+ break
+ end
+ flunk("should not reach here")
+ end
+ false
+ end
+ assert_same(val, result)
+end
+
+assert "no throw" do
+ assert_equal(:foo, catch(:bar){:foo})
+end
+
+assert "no throw value" do
+ result = catch :foo do
+ throw :foo
+ 1
+ end
+ assert_equal(nil, result)
+end
+
+assert "pass the given tag to block" do
+ tag = [:foo]
+ catch(tag){|t| assert_same(tag, t)}
+end
+
+assert "tag identity" do
+ assert_raise_with_message_pattern(Exception, "uncaught throw *") do
+ catch [:tag] do
+ throw [:tag]
+ end
+ flunk("should not reach here")
+ end
+end
+
+assert "without catch arguments" do
+ result = catch do |tag1|
+ catch do |tag2|
+ throw tag1, 1
+ flunk("should not reach here 1")
+ end
+ flunk("should not reach here 2")
+ end
+ assert_equal(1, result)
+end
+
+assert "catches across invocation boundaries" do
+ v = []
+ catch :one do
+ v << 1
+ catch :two do
+ v << 2
+ throw :one
+ v << 3
+ end
+ v << 4
+ end
+ assert_equal([1,2], v)
+end
+
+assert "catches in the nested invocation with the same key" do
+ v = []
+ catch :tag do
+ v << 1
+ catch :tag do
+ v << 2
+ throw :tag
+ v << 3
+ end
+ v << 4
+ end
+ assert_equal([1,2,4], v)
+end

Make the argument of `Kernel#catch` optional as Ruby does

Also implement the following changes.

* Add tests
* Use `Object#equal?` to compare tags for Ruby compatibility
* Use `attr_reader`