Merge pull request #312 from gradha/pr_adds_some_docs_about_exceptions

Adds some documentation related to exceptions.

2 files changed, 31 insertions, 0 deletions

diff --git a/doc/manual.txt b/doc/manual.txt
index 2a79c0f99..80a5642c5 100755
--- a/doc/manual.txt
+++ b/doc/manual.txt
@@ -2843,6 +2843,23 @@ in an implicit try block:
   finally: close(f)
   ...
 
+The ``except`` statement has a limitation in this form: you can't specify the
+type of the exception, you have to catch everything. Also, if you want to use
+both ``finally`` and ``except`` you need to reverse the usual sequence of the
+statements. Example:
+
+.. code-block:: nimrod
+  proc test() =
+    raise newException(E_base, "Hey ho")
+  
+  proc tester() =
+    finally: echo "3. Finally block"
+    except: echo "2. Except block"
+    echo "1. Pre exception"
+    test()
+    echo "4. Post exception"
+  # --> 1, 2, 3 is printed, 4 is never reached
+
 
 Raise statement
 ---------------
diff --git a/doc/tut2.txt b/doc/tut2.txt
index 9f9dbe2db..4a4ef1757 100755
--- a/doc/tut2.txt
+++ b/doc/tut2.txt
@@ -433,6 +433,20 @@ handled, it is propagated through the call stack. This means that often
 the rest of the procedure - that is not within a ``finally`` clause -
 is not executed (if an exception occurs).
 
+If you need to *access* the actual exception object or message inside an
+``except`` branch you can use the getCurrentException() and
+getCurrentExceptionMsg() procs from the `system <system.html>`_ module.
+Example:
+
+.. code-block:: nimrod
+  try:
+    doSomethingHere()
+  except:
+    let
+      e = getCurrentException()
+      msg = getCurrentExceptionMsg()
+    echo "Got exception ", repr(e), " with message ", msg
+
 
 Exception hierarchy
 -------------------