Add tryReadChan to Chan
Now that isEmptyChan is deprecated (#4154 (closed)) it would be useful to add tryReadChan. It seems it is possible to define it so that it does not block like isEmptyChan. This is because semantics is a bit different: tryReadChan is allowed to return Nothing also when Chan is non-empty, but it would block. Contrary, isEmptyChan is expected that it would return False only if Chan is really empty.
I have defined also two new MVar functions which helped me implementing tryReadChan: tryReadMVar and tryModifyMVar. Probably it would be useful to make them public.
Please comment. I propose three weeks for discussion.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 7.1 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | libraries/base |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | mmitar@gmail.com |
| Operating system | |
| Architecture |