37 lines
1.0 KiB
Factor
37 lines
1.0 KiB
Factor
! Copyright (C) 2004, 2005 Slava Pestov.
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! See http://factor.sf.net/license.txt for BSD license.
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IN: kernel
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DEFER: with-continuation
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DEFER: continue-with
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IN: errors
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USING: kernel-internals lists ;
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! This is a very lightweight exception handling system.
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TUPLE: no-method object generic ;
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: no-method ( object generic -- ) <no-method> throw ;
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: catchstack ( -- cs ) 6 getenv ;
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: set-catchstack ( cs -- ) 6 setenv ;
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: >c ( catch -- ) catchstack cons set-catchstack ;
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: c> ( catch -- ) catchstack uncons set-catchstack ;
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: (catch) ( try -- exception/f )
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[ >c call f c> drop f ] with-continuation nip ;
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: catch ( try catch -- )
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#! Call the try quotation. If an error occurs restore the
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#! datastack, push the error, and call the catch block.
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#! If no error occurs, push f and call the catch block.
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>r (catch) r> call ;
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: rethrow ( error -- )
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#! Use rethrow when passing an error on from a catch block.
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#! For convinience, this word is a no-op if error is f.
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[ c> continue-with ] when* ;
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GENERIC: error. ( error -- )
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