Exception handling (programming): Difference between revisions

Revision as of 17:02, 7 June 2024

Revision as of 16:47, 22 September 2024

Line 199:

== Condition systems ==

[[Common Lisp]], [[R (programming language)|R]],<ref>{{Cite web |title=R: Condition Handling and Recovery |url=https://search.r-project.org/R/refmans/base/html/conditions.html |access-date=2024-03-25 |website=search.r-project.org}}</ref> [[Dylan (programming language)|Dylan]] and [[Smalltalk]] have a [[condition system]]<ref>{{cite web|author = What Conditions (Exceptions) are Really About|url = http://danweinreb.org/blog/what-conditions-exceptions-are-really-about|title = What Conditions (Exceptions) are Really About|publisher = Danweinreb.org|date = 2008-03-24|access-date = 2014-09-18|url-status = deadusurped|archive-url = https://web.archive.org/web/20130201124021/http://danweinreb.org/blog/what-conditions-exceptions-are-really-about|archive-date = February 1, 2013}}</ref> (see [[Common Lisp#Condition system|Common Lisp Condition System]]) that encompasses the aforementioned exception handling systems. In those languages or environments the advent of a condition (a "generalisation of an error" according to [[Kent Pitman]]) implies a function call, and only late in the exception handler the decision to unwind the stack may be taken.

Conditions are a generalization of exceptions. When a condition arises, an appropriate condition handler is searched for and selected, in stack order, to handle the condition. Conditions that do not represent errors may safely go unhandled entirely; their only purpose may be to propagate hints or warnings toward the user.<ref>{{cite web |url=https://franz.com/support/documentation/11.0/ansicl/section/conditio.htm |title=9.1 Condition System Concepts |publisher=Franz.com |date=2022-07-25 |access-date=2024-06-07 |archive-url=https://web.archive.org/web/20240607165853/https://franz.com/support/documentation/11.0/ansicl/section/conditio.htm |archive-date=2024-06-07 |url-status=live }}</ref>