Add #![deny(missing_docs)] and comprehensive documentation

[Copilot]

Enforces documentation for all public API surface and adds missing documentation throughout the codebase.

Changes

Enforcement

• Added #![deny(missing_docs)] lint to prevent future undocumented public items

Public API Documentation

• Diff: struct, all methods (count_additions, count_removals, is_removed, is_added, postprocessing methods)
• Hunk: struct fields (before, after ranges)
• Algorithm: enum variants with performance characteristics
• TokenSource: trait, associated types, methods
• InternedInput: struct fields (before, after, interner)
• Interner: all public methods
• SliderHeuristic: trait, implementations (IndentHeuristic, NoSliderHeuristic)
• IndentLevel: struct and methods
• Unified diff: UnifiedDiffPrinter trait, UnifiedDiffConfig, BasicLineDiffPrinter

Internal Documentation

• Private fields in core structs (Myers, Postprocessor, FileSlice, Histogram)
• Internal helpers in util.rs, algorithm modules
• Private types (Score, Split, SearchResult, Occurrences, Lcs)
• Algorithm constants and thresholds

Corrections

• Fixed spelling: pathologic→pathological, then→than (comparisons), linux→Linux
• Fixed typos: bvhunks→hunks, insertation→insertion, intutive→intuitive
• Improved grammar and punctuation throughout existing docs

All tests pass, documentation builds cleanly.

Original prompt

Add #![deny(missing_docs)] and document all public fields and methods. Review all existing documentation for spelling and grammar.
While at it, also document all private fields.

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[Copilot]

Pull request overview

This PR enforces comprehensive documentation across the entire codebase by adding #![deny(missing_docs)] and documenting all public and private API surfaces. The changes improve code maintainability by ensuring all functionality is properly explained for both users and contributors.

• Added documentation enforcement with #![deny(missing_docs)] lint
• Documented all public APIs including traits, structs, methods, and fields
• Added internal documentation for private fields and helper functions
• Fixed spelling errors (pathologic→pathological, insertation→insertion, intutive→intuitive, etc.)
• Improved grammar and consistency throughout existing documentation

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/lib.rs	Added comprehensive module-level docs, documented public Diff, Hunk, and Algorithm APIs; fixed spelling and grammar
src/intern.rs	Documented TokenSource trait, InternedInput, and Interner with all public methods and fields
src/unified_diff.rs	Documented UnifiedDiffPrinter trait, UnifiedDiffConfig, BasicLineDiffPrinter, and UnifiedDiff struct
src/slider_heuristic.rs	Documented SliderHeuristic trait and implementations (NoSliderHeuristic, IndentHeuristic, IndentLevel)
src/postprocess.rs	Added documentation for postprocessing methods and internal Postprocessor struct
src/myers.rs	Documented Myers algorithm implementation, internal state, and helper structs
src/myers/preprocess.rs	Documented preprocessing logic, Occurrences enum, and PreprocessedFile
src/myers/middle_snake.rs	Documented MiddleSnakeSearch and SearchResult with algorithm constants
src/myers/slice.rs	Documented FileSlice struct and its fields
src/histogram.rs	Documented histogram algorithm entry point and internal Histogram state
src/histogram/lcs.rs	Documented LCS finding logic, Lcs struct, and LcsSearch state
src/util.rs	Added documentation for utility functions (common prefix/postfix, strip operations, hunk finding)
src/sources.rs	Added module-level documentation and fixed minor grammar issues
src/tests.rs	Fixed spelling errors in comments and renamed test function for clarity

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[Copilot]

Inconsistent punctuation in parameter descriptions. Line 15 should not have a trailing space, and line 16 is missing a period at the end. For consistency with other similar documentation in the codebase (e.g., histogram.rs lines 25-26, unified_diff.rs lines 32-33), both parameter descriptions should end with periods.

Suggested change

	/// * `before` - The token sequence from the first file, before changes
	/// * `after` - The token sequence from the second file, after changes
	/// * `before` - The token sequence from the first file, before changes.
	/// * `after` - The token sequence from the second file, after changes.

[Copilot]

British spelling "minimisation" should use American spelling "minimization" for consistency with the rest of the codebase (e.g., "tokenize" is used instead of "tokenise").

Suggested change

	/// Useful for minimisation of allocation before calls to
	/// Useful for minimization of allocation before calls to

[Byron]

I looked through everything vigorously and think it's a huge step up from what it was before. There is one spot that I think could be looked at, but I am happy to fix it in a follow-up PR or address anything that comes up.

For context, I am currently on a track to make imara-diff v2 usable in gitoxide, and for that I have to get to know it which I do by … making changes like these 😁.

Next up is an attempt to add a fuzz testing, as a quick way to gain incredible coverage and maybe eek out some panics, long runtimes, or high memory. My hope is that this makes clear why TODO: why is this needed is needed.

[Byron]

I am not so sure about this one.

[Byron]

@pascalkuthe This might be interesting for you.

[Byron]

No test fails when the condition is removed.