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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/manual/exceptions.txt | 28 |
1 files changed, 0 insertions, 28 deletions
diff --git a/doc/manual/exceptions.txt b/doc/manual/exceptions.txt index b3727b7cf..7cad1c2b4 100644 --- a/doc/manual/exceptions.txt +++ b/doc/manual/exceptions.txt @@ -99,34 +99,6 @@ re-raise. It follows that the ``raise`` statement *always* raises an exception (unless a raise hook has been provided). -onRaise builtin ---------------- - -`system.onRaise() <system.html#onRaise>`_ can be used to override the -behaviour of ``raise`` for a single ``try`` statement. ``onRaise`` has to be -called within the ``try`` statement that should be affected. - -This allows for a Lisp-like `condition system`:idx:\: - -.. code-block:: nim - var myFile = open("broken.txt", fmWrite) - try: - onRaise do (e: ref Exception)-> bool: - if e of IOError: - stdout.writeln "ok, writing to stdout instead" - else: - # do raise other exceptions: - result = true - myFile.writeln "writing to broken file" - finally: - myFile.close() - -``onRaise`` can only *filter* raised exceptions, it cannot transform one -exception into another. (Nor should ``onRaise`` raise an exception though -this is currently not enforced.) This restriction keeps the exception tracking -analysis sound. - - Exception hierarchy ------------------- |