| Type | Bug | Status | complete | Date | 19-Feb-2013 20:35 |
|---|---|---|---|---|---|
| Version | r3 master | Category | Parse | Submitted by | BrianH |
| Platform | All | Severity | minor | Priority | normal |
| Summary | PARSE regression with THRU at end |
|---|---|
| Description |
A recently introduced regression to PARSE has popped up in recent builds. Apparently, when using the THRU operation to match a value, it is not succeeding when the match brings it to the end of the series. THRU END works. I've only tested with string parsing, as I haven't been able to construct a relevant expression with block parsing that is supposed to succeed, but doesn't. See the example code. Found by Rebolek. 2.100.* versions are not affected, nor is R2. |
| Example code |
>> parse "abcd" [thru "cd" end] == false ; should be true >> parse "abcd" [thru "cd"] == false ; should be true, and it's not the fault of end >> parse "abcd" [thru "abcd" | (print 'alt) 4 skip] alt == true ; the (incorrect) backtracking was triggered, so it doesn't just stop parsing altogether >> parse "abcd" [thru "ab" end | (print 'alt) 4 skip] alt == true ; correct failure in this case, so end's behavior isn't affected |
| Assigned to | n/a | Fixed in | - | Last Update | 18-Aug-2013 13:35 |
|---|
| Comments | |
|---|---|
|
(0003471)
abolka 20-Feb-2013 00:28 |
Oh well, I think that's another regression introduced by the original fix to #682. Unfortunately my fix for one regression caused by that fix didn't catch this second regression as well. I'm on to it. |
|
(0003472)
Ladislav 20-Feb-2013 16:29 |
The description is not correct, in fact. The fact is that THRU does not find the string when it is at the end, i.e., the rule that fails to match in the above example is the THRU rule, not the END rule (the END rule is not even processed by PARSE, in fact).
Taking that into account, the test may look different not mentioning END at all. |
|
(0003475)
abolka 20-Feb-2013 23:08 |
Right, it's THRU that fails here. The tests can be as simple as:
>> parse "abcd" [thru "cd"] == false ;; Expected: true |
|
(0003476)
BrianH 21-Feb-2013 01:34 |
Good catch, ticket adjusted accordingly. |
|
(0003480)
abolka 21-Feb-2013 19:47 |
Fix submitted:
https://github.com/rebol/r3/pull/92 |
|
(0003481)
Ladislav 22-Feb-2013 14:36 |
In the core-tests suite. |
| Date | User | Field | Action | Change |
|---|---|---|---|---|
| 18-Aug-2013 13:35 | Ladislav | Status | Modified | pending => complete |
| 27-Feb-2013 00:41 | BrianH | Status | Modified | submitted => pending |
| 22-Feb-2013 14:36 | Ladislav | Comment : 0003481 | Added | - |
| 21-Feb-2013 19:47 | abolka | Comment : 0003480 | Added | - |
| 21-Feb-2013 01:36 | BrianH | Description | Modified | - |
| 21-Feb-2013 01:34 | BrianH | Comment : 0003476 | Added | - |
| 21-Feb-2013 01:34 | BrianH | Code | Modified | - |
| 21-Feb-2013 01:34 | BrianH | Description | Modified | - |
| 21-Feb-2013 01:34 | BrianH | Summary | Modified | PARSE regression with THRU and END => PARSE regression with THRU at end |
| 20-Feb-2013 23:08 | abolka | Comment : 0003475 | Added | - |
| 20-Feb-2013 16:32 | Ladislav | Comment : 0003472 | Modified | - |
| 20-Feb-2013 16:31 | Ladislav | Comment : 0003472 | Modified | - |
| 20-Feb-2013 16:30 | Ladislav | Comment : 0003472 | Modified | - |
| 20-Feb-2013 16:29 | Ladislav | Comment : 0003472 | Modified | - |
| 20-Feb-2013 16:29 | Ladislav | Comment : 0003472 | Added | - |
| 20-Feb-2013 00:28 | abolka | Comment : 0003471 | Added | - |
| 19-Feb-2013 20:36 | BrianH | Code | Modified | - |
| 19-Feb-2013 20:35 | BrianH | Code | Modified | - |
| 19-Feb-2013 20:35 | BrianH | Description | Modified | - |
| 19-Feb-2013 20:35 | BrianH | Ticket | Added | - |