LogtalkDotOrg / LogtalkDotOrg/logtalk3
B-Prolog 8.1 sub_atom/5 bug
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backend prolog compiler bug
- Dominant language
- Logtalk
- Stars
- 496
- Forks
- 34
- PR merge metrics
- No merged PRs in 30d
Description
The B-Prolog 8.1 implementation of the standard sub_atom/5 predicate can return an integer instead a (sub-)atom. For example:
| ?- sub_atom('foo#0', 4, _, 0, Atom).
Atom = 0
yes
| ?- sub_atom('foo#0', 4, _, 0, Atom), atom(Atom).
no
This bug is exposed by Logtalk in some of the unit tests for the built-in logtalk object and in errors when converting internal entity prefixes back to entity names.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
The report names B-Prolog 8.1's sub_atom/5 predicate and Logtalk's built-in logtalk unit tests, but no repository file. Start by locating those tests and the entity-prefix conversion path; done means sub_atom/5 yields an atom for 'foo#0' and the affected tests and conversions no longer fail.
Written by the indexing model from the issue text.
Assessment
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 25/100