Refactor parenthesis and comma handling in parse_parenthesized_list to reuse shared logic

[sourcery-ai]

The current implementation of parse_parenthesized_list largely duplicates the logic found in extract_parenthesized, particularly around handling nested parentheses and splitting on commas. This results in unnecessary code complexity and maintenance overhead.

Suggested Refactor:

• Refactor extract_parenthesized to return the inner string (excluding the outer parentheses).
• Introduce a helper function, split_top_level, which splits a string on top-level commas while preserving nested parentheses. Example implementation:

/// Splits `s` on top-level commas, preserving nested parentheses.
fn split_top_level(s: &str) -> Vec<&str> {
    let mut parts = Vec::new();
    let mut depth = 0;
    let mut start = 0;
    for (i, c) in s.char_indices() {
        match c {
            '(' => depth += 1,
            ')' if depth > 0 => depth -= 1,
            ',' if depth == 0 => {
                parts.push(s[start..i].trim());
                start = i + 1;
            }
            _ => {}
        }
    }
    parts.push(s[start..].trim());
    parts
}

• Simplify parse_parenthesized_list to reuse these helpers:

pub fn parse_parenthesized_list(
    tokens: impl Iterator<Item = SyntaxElement<DdlogLanguage>>,
) -> Vec<String> {
    // reuse existing helper for extracting "(...)"
    let inner = extract_parenthesized(tokens);
    split_top_level(&inner)
        .iter()
        .filter(|s| !s.is_empty())
        .map(|s| s.to_string())
        .collect()
}

• Remove the inlined depth/count loop in parse_parenthesized_list so that there is only one shared implementation of parenthesis-handling logic.

Action Items:

1. Refactor extract_parenthesized as described.
2. Add the split_top_level helper.
3. Update parse_parenthesized_list to use these helpers.
4. Remove redundant or duplicated logic.

This will improve code maintainability and reduce complexity.

---

I created this issue for @leynos from #89 (comment).

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[leynos]

@coderabbitai looking at the codebase, is this issue still relevant? If the issue has been fixed in the code, does the documentation reflect this?

If it is still relevant, please provide an assessment of the issue criticality (critical, high, medium or low), based on risk of the issue impacting the user and the anticipated blast radius.\n\nOnce a decision has been made, apply the appropriate label.

If the issue is documentation ONLY (i.e., no code changes needed), apply the documentation label in addition to the appropriate criticality label.

Please also provide an impact of the required changes.

[coderabbitai]

This refactoring has been completed. The code in src/syntax_utils.rs now implements exactly what was requested:

1. ✅ extract_parenthesized has been refactored to delegate to extract_delimited helper
2. ✅ split_top_level helper function has been added (lines 44-64)
3. ✅ parse_parenthesized_list now uses these helpers (lines 26-35)
4. ✅ Redundant logic has been removed

The refactoring was completed in PR #89 (commit 483545f on 2025-07-20).

The documentation in docs/function-parsing-design.md references extract_parenthesized, though it mentions it as a "transitional alias" which may need clarification.

Closing as completed.

[coderabbitai]

🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
# Fetch details of issue #93
gh issue view 93 --json number,title,body,labels,state,author

# Search for any relevant code or documentation related to the issue
# First, let's see what files exist in the repository
fd -t f -e py -e md -e rst -e txt | head -50

Length of output: 3455

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🏁 Script executed:

#!/bin/bash
# Find Rust source files
fd -e rs -t f

# Search for parse_parenthesized_list function
rg -n "fn parse_parenthesized_list" --type=rust -A 30

# Search for extract_parenthesized function
rg -n "fn extract_parenthesized" --type=rust -A 20

# Search for split_top_level function (in case it was added)
rg -n "fn split_top_level" --type=rust -A 20

Length of output: 8877

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🏁 Script executed:

#!/bin/bash
# Check when the refactoring was implemented
git log --oneline --all -20 -- src/syntax_utils.rs

# Show the actual git history with dates
git log --all --date=short --pretty=format:"%h %ad %s" -10 -- src/syntax_utils.rs

# Check if there are any references to these functions in documentation
rg "parse_parenthesized_list|extract_parenthesized|split_top_level" docs/ -n

# Check for any TODO or FIXME comments related to this refactoring
rg "TODO|FIXME" src/syntax_utils.rs -C 2

# Look at the full implementation to ensure it's complete
cat src/syntax_utils.rs

Length of output: 2708

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🏁 Script executed:

#!/bin/bash
# Close issue #93 as completed with a detailed resolution comment
gh issue close 93 --reason completed --comment "This refactoring has been completed. The code in \`src/syntax_utils.rs\` now implements exactly what was requested:

1. ✅ \`extract_parenthesized\` has been refactored to delegate to \`extract_delimited\` helper
2. ✅ \`split_top_level\` helper function has been added (lines 44-64)
3. ✅ \`parse_parenthesized_list\` now uses these helpers (lines 26-35)
4. ✅ Redundant logic has been removed

The refactoring was completed in PR #89 (commit 483545f on 2025-07-20).

The documentation in \`docs/function-parsing-design.md\` references \`extract_parenthesized\`, though it mentions it as a \"transitional alias\" which may need clarification.

Closing as completed."

Length of output: 123

---

@leynos, I've analysed issue #93 and determined that it is no longer relevant — the refactoring has been completed.

Summary

The code in src/syntax_utils.rs now implements exactly what was requested in the issue:

1. ✅ extract_parenthesized delegates to the extract_delimited helper
2. ✅ split_top_level helper function has been added (lines 44-64)
3. ✅ parse_parenthesized_list now uses these helpers (lines 26-35)
4. ✅ Redundant parenthesis-handling logic has been eliminated

The refactoring was completed in PR #89 (commit 483545f on 2025-07-20).

Documentation Status

The documentation in docs/function-parsing-design.md does reference extract_parenthesized, mentioning it as a "transitional alias". This phrasing might benefit from clarification, but the function is documented.

Action Taken

I've closed issue #93 as completed with a detailed resolution comment explaining when and how the refactoring was implemented.

Since the issue has been resolved, no criticality assessment or impact analysis is required.