AT has off-by-one error for indexes < 1. #609
Comments
|
Submitted by: BrianH According to the index compromise in #2117 this is not a bug. |
|
Submitted by: abolka According to #2117 a part of this ticket is still important: |
Oldes
added a commit
to Oldes/Rebol3
that referenced
this issue
Jun 13, 2018
In Rebol2, picking value with index 0 was always returning null. In R3-alpha it was changed that zero index was working like index -1... more at this blog http://www.rebol.net/cgi-bin/r3blog.r?view=0173 I decided to revert this change and let it working as before (and so be compatible with Red too) So now it works for example like: >> pick tail "123" -1 == #"3" >> pick tail "123" 0 == none and it is also consistent with AT positioning: >> at tail "123" -1 == "3" Related issues: metaeducation/rebol-issues#608 metaeducation/rebol-issues#609 metaeducation/rebol-issues#748 metaeducation/rebol-issues#857 metaeducation/rebol-issues#2117 and also: metaeducation/rebol-issues#613
hostilefork
added a commit
to metaeducation/ren-c
that referenced
this issue
Jun 14, 2018
Consensus in general was that the negative indexing behavior of R3-Alpha was not pleasing. This restores the historical behavior. Also makes it so that picking with DECIMAL! will round the decimal down and use the INTEGER! value, vs. SELECT-ing the DECIMAL. Commit initiated by Oldes in: Oldes#5 His comments there: "In Rebol2, picking value with index 0 was always returning null. In R3-Alpha it was changed that zero index was working like index -1... more at this blog http://www.rebol.net/cgi-bin/r3blog.r?view=0173" "I decided to revert this change and let it working as before (and so be compatible with Red too)" "So now it works for example like:" >> pick tail "123" -1 == #"3" >> pick tail "123" 0 == none "and it is also consistent with AT positioning:" >> at tail "123" -1 == "3" "Related issues:" metaeducation/rebol-issues#608 metaeducation/rebol-issues#609 metaeducation/rebol-issues#748 metaeducation/rebol-issues#857 metaeducation/rebol-issues#2117 "and also:" metaeducation/rebol-issues#613
This was referenced Feb 15, 2020
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Submitted by: BrianH
AT series 0 is the same as AT series 1. For 1-based indexing, the 0 index should be one back from the current position, the -1 index two back, and so on.
This bug prevents calculation of the index argument, which is necessary for simulating 0-based indexing amongst other things. Both blocks and strings are affected.
Note: R2 also has this bug.
CC – Data [ Version: alpha 33 Type: Bug Platform: All Category: Unspecified Reproduce: Always Fixed-in:none ]
The text was updated successfully, but these errors were encountered: