cut: match GNU diagnostics for invalid ranges and options

[sylvestre]

Produce GNU's mode-aware messages (fields vs byte/character positions),
distinguish empty/invalid/decreasing/no-endpoint ranges, and align the
usage errors, all with the 'Try --help' hint.

Should make test tests/cut/cut.pl pass

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[Copilot]

Pull request overview

This PR updates cut’s argument/range parsing diagnostics to better match GNU cut, including mode-aware messages (fields vs byte/character positions) and “usage”-style failures that include the “Try --help” hint.

Changes:

• Add a GNU-aligned range-list parser in cut to produce more specific diagnostics (empty/invalid/decreasing/no-endpoint/too-large).
• Switch several error paths from USimpleError to UUsageError so they’re treated as usage errors (with the help hint).
• Update cut’s locale strings and expand tests to assert the new diagnostic wording.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/by-util/test_cut.rs	Adjusts existing assertions and adds a new test matrix for GNU-like range/option diagnostics.
src/uucore/src/lib/features/ranges.rs	Exposes Range::merge publicly so cut can merge parsed ranges after custom parsing.
src/uu/cut/src/cut.rs	Implements mode-aware range parsing + updates multiple error paths to UUsageError.
src/uu/cut/locales/fr-FR.ftl	Updates French diagnostic strings and adds new range-related message keys.
src/uu/cut/locales/en-US.ftl	Updates English diagnostic strings and adds new range-related message keys.

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[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/date/date-locale-hour (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/misc/io-errors (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/tail/retry (fails in this run but passes in the 'main' branch)
Congrats! The gnu test tests/csplit/csplit-heap is now passing!

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.

Suppressed comments (1)

src/uu/cut/src/cut.rs:66

• Doc comment mentions a -F option for field mode, but this utility only defines -f/--fields (no -F). This can mislead future maintainers when interpreting the mode-specific diagnostics logic.

/// GNU's range-list diagnostics, worded for field mode (`-f`/`-F`) or for
/// byte/character mode (`-b`/`-c`).

[codspeed-hq]

Merging this PR will regress 1 benchmark

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 5 improved benchmarks
❌ 1 regressed benchmark
✅ 347 untouched benchmarks
⏩ 50 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	du_wide_tree[(5000, 500)]	19.3 ms	20.2 ms	-4.52%
⚡	Simulation	numfmt_to_si[10000]	94.4 ms	91.3 ms	+3.4%
⚡	Simulation	numfmt_round_modes[("up", 10000)]	95.8 ms	92.7 ms	+3.35%
⚡	Simulation	numfmt_large_numbers_si[10000]	100.3 ms	97.2 ms	+3.2%
⚡	Simulation	numfmt_padding[(10000, 50)]	100.2 ms	97.1 ms	+3.2%
⚡	Simulation	numfmt_to_si_precision[10000]	97.5 ms	94.6 ms	+3.11%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing cut-diag (ce4cf44) with main (9516e99)}

Footnotes

1. 50 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. ↩