feat(checker): examples() and spec_files() carry the specification's files

A consumer of the checker crate needs no path into this repository.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp

target/doc/bookspec_checker/engine/index.html

@@ -0,0 +1,15 @@
+<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="The interface an accounting engine implements to be checked against bookspec (`plan/served.md` P13, D-34)."><title>bookspec_checker::engine - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Italic-81dc35de.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-MediumItalic-ccf7e434.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2"href="../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../static.files/rustdoc-0c87338a.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="bookspec_checker" data-themes="" data-resource-suffix="" data-rustdoc-version="1.99.1 (58cf8f9c3 2026-10-13)" data-channel="1.99.1" data-search-js="search-cf4fc35e.js" data-stringdex-js="stringdex-b5109af9.js" data-settings-js="settings-170eb4bf.js" ><script src="../../static.files/storage-41dd4d93.js"></script><script defer src="../sidebar-items.js"></script><script defer src="../../static.files/main-417ebf0a.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-9f56287d.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-eab170b8.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-044be391.svg"></head><body class="rustdoc mod"><a class="skip-main-content" href="#main-content">Skip to main content</a><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><rustdoc-topbar><h2><a href="#">Module engine</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../../bookspec_checker/index.html">bookspec_<wbr>checker</a><span class="version">0.1.0</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">Module engine</a></h2><h3><a href="#structs">Module Items</a></h3><ul class="block"><li><a href="#structs" title="Structs">Structs</a></li><li><a href="#traits" title="Traits">Traits</a></li><li><a href="#functions" title="Functions">Functions</a></li></ul></section><div id="rustdoc-modnav"><h2 class="in-crate"><a href="../index.html">In crate bookspec_<wbr>checker</a></h2></div></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><div class="width-limiter"><section id="main-content" class="content" tabindex="-1"><div class="main-heading"><div class="rustdoc-breadcrumbs"><a href="../index.html">bookspec_checker</a></div><h1>Module <span>engine</span>&nbsp;<button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../../src/bookspec_checker/engine.rs.html#1-224">Source</a> </span></div><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>The interface an accounting engine implements to be checked against
+bookspec (<code>plan/served.md</code> P13, D-34).</p>
+<p>bookspec is a specification first: its examples are the concrete cases
+(<code>bookspec/examples/*.toml</code>), its rule identifiers the normative rules
+(<code>BS-&lt;area&gt;-&lt;n&gt;</code>), and this trait the only thing an engine has to
+provide for the runner to check it. The engine’s answers are compared
+with the examples’ expected values by the runner; an engine is never
+asked whether it agrees with itself.</p>
+</div></details><h2 id="structs" class="section-header">Structs<a href="#structs" class="anchor">§</a></h2><dl class="item-table"><dt><a class="struct" href="struct.Claims.html" title="struct bookspec_checker::engine::Claims">Claims</a></dt><dd>What an engine declares about itself: the rules it takes the
+conformance test on, and the option it picks for each of the
+specification’s choices (<code>CHOICE</code>: the specification names the options,
+an engine declares its pick; <code>plan/served.md</code> P13 step 3).</dd><dt><a class="struct" href="struct.Refusal.html" title="struct bookspec_checker::engine::Refusal">Refusal</a></dt><dd>An engine’s refusal: the rule that refuses, and why in the example’s
+words (bookspec/README.md’s refusal vocabulary, never an engine’s own
+message).</dd><dt><a class="struct" href="struct.RuleId.html" title="struct bookspec_checker::engine::RuleId">RuleId</a></dt><dd>A bookspec rule identifier: <code>BS-&lt;area&gt;-&lt;n&gt;</code> (e.g. <code>BS-entry-1</code>).</dd><dt><a class="struct" href="struct.RuleIdError.html" title="struct bookspec_checker::engine::RuleIdError">Rule<wbr>IdError</a></dt><dd>Why a string is not a bookspec rule identifier.</dd></dl><h2 id="traits" class="section-header">Traits<a href="#traits" class="anchor">§</a></h2><dl class="item-table"><dt><a class="trait" href="trait.Engine.html" title="trait bookspec_checker::engine::Engine">Engine</a></dt><dd>An accounting engine, as bookspec checks it.</dd></dl><h2 id="functions" class="section-header">Functions<a href="#functions" class="anchor">§</a></h2><dl class="item-table"><dt><a class="fn" href="fn.fallback_refusal.html" title="fn bookspec_checker::engine::fallback_refusal">fallback_<wbr>refusal</a></dt><dd>The refusal an engine reports for an error it has no example-word
+reason for: the reason as given, under <code>fallback</code>.</dd></dl></section></div></main></body></html>