Fix (|) parsing per ISO TC2 C2: operator-dependent validity #3141
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Fixes mthom#3140 The parser was incorrectly accepting (|) and converting it to the atom '|', when it should produce a syntax_error according to ISO/IEC 13211-1 Technical Corrigendum 2, Section C2. Changes: - Modified reduce_brackets() in parser.rs to reject HeadTailSeparator inside parentheses, treating (|) as incomplete/forbidden syntax - Updated builtins.pl to use quoted atom '|' instead of (|) in error term - Added comprehensive tests in src/tests/iso_syntax_errors.pl covering: * (|) syntax error * ISO operator creation restrictions for {} and '|' * Valid operator declarations with proper priorities
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… artifacts Two fixes: 1. ISO TC2 C2 compliance for (|): - (|) now only valid when | IS an operator - When | is not an operator, (|) produces syntax_error - Pass op_dir to reduce_brackets() to check operator status 2. Issue mthom#3170 - LR artifacts fix: - reduce_curly() now rejects unreduced operators - Added is_op!(td.spec) check to prevent garbage output - {!*!(|)/} now correctly errors instead of producing {/} Tests: 20 new tests in lr_artifacts_3170.pl covering both fixes Refs: - mthom#3170 - https://www.complang.tuwien.ac.at/ulrich/iso-prolog/dtc2#C2
- Fix catch/3 patterns: use (Goal, false) to properly detect when Goal succeeds instead of throwing expected error - Add .stdout files for snapshot testing (expect "All tests passed") - Add lr_artifacts_3170.toml for CLI test integration - Remove op_create_bar_in_list test: list syntax bypasses op validation (separate bug, out of scope for this PR)
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- (|) when | IS an operator → valid, parses as atom '|'
It remains invalid.
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Per clarification on Issue #4 and conformity test s#360: - (|) must be a syntax error regardless of operator status - Even with op(1105,xfy,'|'), writeq((|)) must error - The only valid way to write bar as atom is '|' (quoted) Changes: - Simplify reduce_brackets() to always reject HeadTailSeparator - Remove op_dir parameter (no longer needed) - Update lr_artifacts_3170 tests to use '|' instead of (|) - Add conformity test s#360: (|) errors even with op defined - Add test verifying '|' (quoted) is valid
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(|)is NEVER valid syntax (conformity test s#360)Even with
op(1105,xfy,'|'),(|)must error. Use'|'(quoted) for the atom.Per ISO 6.4.2:
|is not a name token (unlike!and;), so cannot be parenthesized.Changes
reduce_brackets(): Always rejectHeadTailSeparator'|'instead of(|)Ref: https://www.complang.tuwien.ac.at/ulrich/iso-prolog/conformity_testing#360