refactor(math): clean up fmt

[Eh2406]

A small PR, to learn the process and etiquette with this project.

print_fixedp did not take full advantage of the formatting options int write! dsl. By inlining it into the one place it was called, a bunch of code could be made simpler.

Summary by CodeRabbit

• Refactor
  • Simplified Decimal display formatting logic by streamlining the internal implementation and removing redundant code structures.

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[coderabbitai]

📝 Walkthrough

Walkthrough

Display formatting for the Decimal type in pallas-math was refactored. The fmt method now inlines logic to compute integer and fractional parts using div_rem, handle sign explicitly, and normalize negative values. The separate print_fixedp helper function was removed.

Changes

Cohort / File(s)	Summary
Decimal Display Refactoring pallas-math/src/math_dashu.rs	Reworked fmt method for Display trait: replaced print_fixedp helper call with inline logic using div_rem to split integer and fractional parts, explicit sign handling via conditional minus write, normalization of negative quotients/remainders to absolute values, and formatted output with precision-based width. Removed now-unused print_fixedp free function.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Poem

🐰 Whiskers twitch with joy—no more helpers to call,
The fmt method now handles it all!
Div and rem dance, signs align just right,
Decimal formats shine, crisp and bright! ✨

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'refactor(math): clean up fmt' accurately describes the main change: refactoring the Display formatting code for Decimal by inlining the print_fixedp helper and simplifying the fmt method.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (1)

pallas-math/src/math_dashu.rs (1)

43-55: Consider simplifying sign handling with abs().

The logic is correct but could be more idiomatic. Instead of negating temp_q and temp_r conditionally, you could use abs():

🔎 Proposed simplification using abs()

 let is_negative = self.data < ZERO.value;
-let (mut temp_q, mut temp_r) = (&self.data).div_rem(&self.precision_multiplier);
+let (temp_q, temp_r) = (&self.data).abs().div_rem(&self.precision_multiplier);

 if is_negative {
     f.write_str("-")?;
 }

-if temp_q < ZERO.value {
-    temp_q = temp_q.neg();
-}
-if temp_r < ZERO.value {
-    temp_r = temp_r.neg();
-}
 write!(
     f,

This computes the absolute value once before div_rem, eliminating the need to check and negate both quotient and remainder separately.

📜 Review details

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 2aba7ff and fe3a596.

📒 Files selected for processing (1)

• pallas-math/src/math_dashu.rs

🧰 Additional context used

🧬 Code graph analysis (1)

pallas-math/src/math_dashu.rs (1)

pallas-math/src/math.rs (1)

• precision (37-37)

🔇 Additional comments (1)

pallas-math/src/math_dashu.rs (1)

41-62: LGTM! Clean refactoring that inlines the formatting logic.

The refactoring successfully inlines the print_fixedp helper, making fuller use of the write! formatting DSL. The logic correctly handles sign, computes integer and fractional parts, and formats with proper zero-padding.