Changeset b580bcc for doc/theses

Timestamp:

Apr 1, 2021, 4:20:00 PM (4 years ago)

Author:

Peter A. Buhr <pabuhr@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

fd1f65e

Parents:

3bd2464 (diff), 198e335 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc

File:

• doc/theses/andrew_beach_MMath/future.tex (modified) (1 diff)

doc/theses/andrew_beach_MMath/future.tex

@@ -83 +83 @@
 patterns to find the handler.
 
+\section{Checked Exceptions}
+Checked exceptions make exceptions part of a function's type by adding the
+exception signature. An exception signature must declare all checked
+exceptions that could propogate from the function (either because they were
+raised inside the function or came from a sub-function). This improves safety
+by making sure every checked exception is either handled or consciously
+passed on.
+
+However checked exceptions were never seriously considered for this project
+for two reasons. The first is due to time constraints, even copying an
+existing checked exception system would be pushing the remaining time and
+trying to address the second problem would take even longer. The second
+problem is that checked exceptions have some real usability trade-offs in
+exchange for the increased safety.
+
+These trade-offs are most problematic when trying to pass exceptions through
+higher-order functions from the functions the user passed into the
+higher-order function. There are no well known solutions to this problem
+that were statifactory for \CFA (which carries some of C's flexability
+over safety design) so one would have to be researched and developed.
+
+Follow-up work might add checked exceptions to \CFA, possibly using
+polymorphic exception signatures, a form of tunneling\cite{Zhang19} or
+checked and unchecked raises.
+
 \section{Zero-Cost Try}
 \CFA does not have zero-cost try-statements because the compiler generates C