refactor: order validation checks by parameter position in stats/base/dists/cauchy/*

[Planeshifter]

Aligning validation prologues across stats/base/dists/cauchy/* to follow parameter declaration order, per @Planeshifter's review feedback on this PR. Originally surfaced by a cross-package API drift sweep over the namespace; the routine identified quantile as the lone outlier under a majority-vote model, but parameter-order is the correct convention and applies in the opposite direction (everything but ctor needs the swap).

Description

Eight commits, one per outlier package, each a 1-line guard reorder. Behavior is unchanged in every case — every branch in the disjunction returns NaN, so swapping the order of the operands does not affect any observable result.

Package	Signature	Before (NaN guards)	After (NaN guards)
cdf	(x, x0, gamma)	x, gamma, x0	x, x0, gamma
logcdf	(x, x0, gamma)	x, gamma, x0	x, x0, gamma
logpdf	(x, x0, gamma)	x, gamma, x0	x, x0, gamma
pdf	(x, x0, gamma)	x, gamma, x0	x, x0, gamma
entropy	(x0, gamma)	gamma, x0	x0, gamma
median	(x0, gamma)	gamma, x0	x0, gamma
mode	(x0, gamma)	gamma, x0	x0, gamma
quantile	(p, x0, gamma)	gamma, x0, …, p	p, x0, gamma, …

ctor is untouched — it's a class constructor that throws TypeError via format rather than returning NaN, and its existing checks already follow (x0, gamma) order.

Related Issues

None.

Questions

None.

Other

Validation

• Reorders are within the operands of a single boolean disjunction whose every branch returns NaN; observable behavior is unchanged.
• The quantile test suite (test/test.js, test/test.factory.js, test/test.native.js) only asserts isnan(result) === true on invalid inputs and never inspects which check fired. Same is true for the other seven test suites — they exercise NaN inputs but assert only on the result, not on ordering.
• Cross-reference: ctor/lib/main.js validates x0/gamma itself before forwarding to the numeric siblings, so it is unaffected by the internal prologue order in those siblings.

Out of scope

• lib/factory.js files in cdf, logcdf, logpdf, pdf, quantile show the same parameter-order convention drift (and quantile/lib/factory.js additionally uses gamma <= 0 instead of gamma <= 0.0). Logged as a follow-up — happy to fold them into this PR if preferred.

Checklist

• Read, understood, and followed the contributing guidelines.

AI Assistance

• Yes
• No

If you answered "yes" above, how did you use AI assistance?

• Code generation (e.g., when writing an implementation or fixing a bug)
• Test/benchmark generation
• Documentation (including examples)
• Research and understanding

Disclosure

This PR was authored by Claude Code. The initial commit (a709d01) was produced by an automated cross-package API drift sweep over the stats/base/dists/cauchy namespace using a 75% majority-vote model. After @Planeshifter's review feedback that validation order should follow parameter declaration order, eight follow-up commits were authored mechanically to apply that convention across the seven sibling packages and to redirect the quantile reorder accordingly.

---

@stdlib-js/reviewers

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/cauchy/cdf	$\color{green}287/287$ $\color{green}+100.00%$	$\color{green}19/19$ $\color{green}+100.00%$	$\color{green}4/4$ $\color{green}+100.00%$	$\color{green}287/287$ $\color{green}+100.00%$
stats/base/dists/cauchy/entropy	$\color{green}161/161$ $\color{green}+100.00%$	$\color{green}9/9$ $\color{green}+100.00%$	$\color{green}2/2$ $\color{green}+100.00%$	$\color{green}161/161$ $\color{green}+100.00%$
stats/base/dists/cauchy/logcdf	$\color{green}289/289$ $\color{green}+100.00%$	$\color{green}19/19$ $\color{green}+100.00%$	$\color{green}4/4$ $\color{green}+100.00%$	$\color{green}289/289$ $\color{green}+100.00%$
stats/base/dists/cauchy/logpdf	$\color{green}293/293$ $\color{green}+100.00%$	$\color{green}19/19$ $\color{green}+100.00%$	$\color{green}4/4$ $\color{green}+100.00%$	$\color{green}293/293$ $\color{green}+100.00%$
stats/base/dists/cauchy/median	$\color{green}159/159$ $\color{green}+100.00%$	$\color{green}9/9$ $\color{green}+100.00%$	$\color{green}2/2$ $\color{green}+100.00%$	$\color{green}159/159$ $\color{green}+100.00%$
stats/base/dists/cauchy/mode	$\color{green}159/159$ $\color{green}+100.00%$	$\color{green}9/9$ $\color{green}+100.00%$	$\color{green}2/2$ $\color{green}+100.00%$	$\color{green}159/159$ $\color{green}+100.00%$
stats/base/dists/cauchy/pdf	$\color{green}293/293$ $\color{green}+100.00%$	$\color{green}19/19$ $\color{green}+100.00%$	$\color{green}4/4$ $\color{green}+100.00%$	$\color{green}293/293$ $\color{green}+100.00%$
stats/base/dists/cauchy/quantile	$\color{green}306/306$ $\color{green}+0.00%$	$\color{green}23/23$ $\color{green}+0.00%$	$\color{green}4/4$ $\color{green}+0.00%$	$\color{green}306/306$ $\color{green}+0.00%$

The above coverage report was generated for the changes in this PR.

[Planeshifter]

We should instead change all the other packages since the order of the checks should follow the parameter order.

[Planeshifter]

Done — pushed eight follow-up commits, one per package, reordering the NaN guards to match parameter declaration order in cdf, logcdf, logpdf, pdf, entropy, median, mode, and quantile. ctor is untouched (it already follows (x0, gamma) order and uses a different exception-based validation path).

Updated the PR title and body to reflect the new direction.

Note: lib/factory.js in cdf/logcdf/logpdf/pdf/quantile shows the same drift; left out of scope for now but can fold into this PR if you'd prefer to keep it together.

---

Generated by Claude Code

[Planeshifter]

Note: lib/factory.js in cdf/logcdf/logpdf/pdf/quantile shows the same drift; left out of scope for now but can fold into this PR if you'd prefer to keep it together.

Let's address this too.

[Planeshifter]

Folded the lib/factory.js reorders into this PR — five additional commits:

• cdf, logcdf, logpdf, pdf: swap NaN guards so the order matches factory(x0, gamma).
• quantile: factory order was already correct; only normalized the scale-parameter guard from gamma <= 0 to gamma <= 0.0 to match the four siblings' float-literal style.

Behavior is unchanged in all five files.

---

Generated by Claude Code