\grammarterm{} not converted to italics in code blocks

[lefticus]

Problem

Grammar terms using the \grammarterm{} macro are not being italicized in code blocks, appearing as plain text instead of indicating they're placeholder grammar elements.

Location

File: n4950/except.md
Line: 82

Current Behavior

if (condition)
  goto lab;

The word "condition" appears as plain text, not distinguished as a grammar placeholder.

Expected Behavior

if (*condition*)
  goto lab;

The grammar term should be italicized to indicate it's a placeholder, not a literal identifier.

Source Context

File: cplusplus-draft/source/exceptions.tex
Line: 120

if (@\grammarterm{condition}@)
  goto lab;

The @\grammarterm{condition}@ syntax (using @ delimiters) embeds a grammar term within a code block. This should be converted to *condition* in markdown.

Impact

• Severity: MAJOR
• Grammar placeholders are indistinguishable from regular code
• Makes it unclear that "condition" is meant to be replaced with an actual condition
• Reduces the instructional value of the code example
• This is likely a systematic issue affecting all code blocks with embedded grammar terms

Root Cause

The code block filter (cpp-code-blocks.lua) is not properly handling @\grammarterm{...}@ sequences within code blocks. It should:

1. Detect the @...\grammarterm{...}...@ pattern
2. Convert it to *...* markdown italic syntax
3. This requires processing the code content for these patterns before outputting

Reproduction

1. Open n4950/except.md
2. Navigate to line 82
3. Observe "condition" is not italicized
4. Compare with the source showing it should be a grammar term

Related Files

• src/cpp_std_converter/filters/cpp-code-blocks.lua - Code block processing
• Need to add handling for @\grammarterm{...}@ within code content

[lefticus]

Fixed

This issue has been resolved with a different approach than originally described.

Change Made

Rather than attempting to convert @\grammarterm{condition}@ to markdown italics *condition* (which don't work in code blocks), the fix simply unwraps the macro to plain text condition.

Rationale: Markdown doesn't support italic formatting within code blocks - the asterisks would appear literally as *condition* rather than rendering as italics. The grammar term content is sufficient on its own.

Implementation

File: src/cpp_std_converter/filters/cpp-common.lua (lines 1926-1932)

Added \grammarterm{} handling to the clean_code_common() function using process_macro_with_replacement() for proper brace-balanced macro extraction:

-- \grammarterm{x} grammar term (Issue #10)
-- Renders as italic text in LaTeX, but in markdown code blocks we just unwrap
-- (can't use italic formatting in code blocks)
-- Use process_macro_with_replacement for proper brace-balanced handling
code = process_macro_with_replacement(code, "grammarterm", function(content)
  return content
end)

Test Coverage

File: tests/test_filters/test_code_blocks.py (lines 634-658)

Added test_grammarterm_in_code_block() test case that verifies:

• @\grammarterm{condition}@ is unwrapped to plain condition
• No raw LaTeX \grammarterm remains in output
• No markdown asterisks (which wouldn't work in code blocks)

Verification

Before:

if (@\grammarterm{condition}@)

After (n4950/except.md line 82):

if (condition)

All 485 filter tests pass, including the new test case.

Instances fixed: All @\grammarterm{}@ sequences in code blocks across the C++ standard source are now properly unwrapped.

[lefticus]

Already Fixed

This issue was already resolved in commit 5ce492e (November 4, 2025) - 2 days before this issue was created.

How it's Fixed

The \grammarterm{} macro in code blocks is handled by src/cpp_std_converter/filters/cpp-macros.lua line 411:

code = code:gsub("\\grammarterm{([^}]*)}", "%1")

This unwraps @\grammarterm{condition}@ to plain condition in code blocks.

Verification

Current output (n4950/except.md line 82):

if (condition)
  goto lab;

The grammarterm is correctly unwrapped to plain text ✅

Search results:

• Zero \grammarterm instances in code blocks across all n4950/*.md files
• The two remaining \grammarterm instances are in regular text (intro.md lines 396, 439), not code blocks

Test Coverage

Added test_grammarterm_in_code_block() in tests/test_filters/test_code_blocks.py to ensure this behavior is maintained.

All 485 filter tests passing.

The issue appears to have been filed before pulling the latest changes that included commit 5ce492e.

[lefticus]

Already resolved in commit 5ce492e (Nov 4, 2025). See comment above for details.