refactor(core): Minor refactor for code readability

[arun-geek]

1. Avoid enumerate for first object check
2. String is immutable and concating repeatedly can have performance issues if used at scale

[codspeed-hq]

CodSpeed Performance Report

Merging #33674 will not alter performance

_{Comparing arun-geek:refactor (163b931) with master (6e036d3)}

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

Summary

✅ 13 untouched
⏩ 21 skipped¹

Footnotes

1. 21 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[ccurme]

this is changing behavior to drop trailing newlines, which could break caches and is arguably not desired.

[ccurme]

I see no compelling reason to make this change, conditioning on i == 0 is clear and readable with no performance issues.