Add trailing newline to axiom rule format for consistency

[Copilot]

Axiom rules (rules with no premises) were inconsistent with multi-premise rules - they lacked a trailing newline after the conclusion.

Changes

• Python (bnf/apyds_bnf/__init__.py): Changed f"----\n{result[0]}" to f"----\n{result[0]}\n" in ParseVisitor.visitRule()
• JavaScript (bnf/atsds_bnf/index.mjs): Changed `----\n${result[0]}` to `----\n${result[0]}\n` in ParseVisitor.visitRule()
• Tests: Updated expectations for axiom parsing/unparsing tests in both languages
• Documentation: Updated syntax table to reflect new axiom format: ----\na\n

Example

# Before: axiom had no trailing newline
parse("a") == "----\na"

# After: consistent trailing newline
parse("a") == "----\na\n"

# Multi-premise rules always had trailing newline (unchanged)
parse("a, b -> c") == "a\nb\n----\nc\n"

Original prompt

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This section details on the original issue you should resolve

<issue_title>bnf中 的 rule 变字符串 需要更新</issue_title>
<issue_description>return f"----\n{result[0]}"
应该是
return f"----\n{result[0]}\n"

上面是python这边的, javascript那边也需要更新, 然后就是/bnf/tests/下面的文件可能也需要更新</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes bnf中 的 rule 变字符串 需要更新 #117

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[Copilot]

Pull request overview

This PR adds a trailing newline to axiom rules (rules with no premises) to ensure consistency with multi-premise rules. Previously, axioms returned ----\na while multi-premise rules ended with \n. Now all rules consistently end with a trailing newline.

Key Changes:

• Modified the axiom formatting logic in both Python and JavaScript implementations to append \n
• Updated all test expectations for axiom parsing and unparsing in both languages
• Updated documentation table in docs/support-packages/bnf.md to reflect the new format

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
bnf/apyds_bnf/init.py	Added trailing newline to axiom rule format in ParseVisitor.visitRule()
bnf/atsds_bnf/index.mjs	Added trailing newline to axiom rule format in ParseVisitor.visitRule()
bnf/tests/test_parse_unparse.py	Updated test expectations for axiom parsing/unparsing to include trailing newline
bnf/tests/test_parse_unparse.mjs	Updated test expectations for axiom parsing/unparsing to include trailing newline
docs/support-packages/bnf.md	Updated syntax comparison table to show new axiom format with trailing newline

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[Copilot]

The axiom format in the bnf/README.md file also needs to be updated to match this change. Line 119 of bnf/README.md still shows ----\na instead of ----\na\n.