mirror of
https://github.com/mruby/mruby
synced 2026-06-08 16:11:16 +00:00
Yukihiro "Matz" Matsumoto
7eaaee5405
Implements `catch`/`throw` non-local jump inherited from Lisp.
`catch([tag]) {|tag| block } -> obj`
Example:
```
catch(:foo) { 123 } # => 123
catch(:foo) { throw(:foo, 456) } # => 456
catch(:foo) { throw(:foo) } # => nil
```
28 lines
423 B
Ruby
28 lines
423 B
Ruby
class ThrowCatchJump < Exception
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def initialize(tag, val)
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@tag = tag
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@val = val
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super("uncaught throw :#{tag}")
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end
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def _tag
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@tag
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end
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def _val
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@val
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end
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end
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module Kernel
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def catch(tag, &block)
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block.call(tag)
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rescue ThrowCatchJump => e
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unless e._tag == tag
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raise e
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end
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return e._val
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end
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def throw(tag, val=nil)
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raise ThrowCatchJump.new(tag, val)
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end
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end
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