Agent-First Slug v0.1.0

Every slug library has a default mode. That default is someone’s guess about your target surface: which characters are allowed, how dots are handled, what to do when the result is empty. For simple cases the guess is right. The moment you’re writing into a local path, a URL segment, and a legacy system in the same codebase, you hit three sets of rules and need to force each one at the call site.

Agent-First Slug v0.1.0 makes the caller state the policy.

One config, all policies

There is a single SlugConfig struct. You fill it in — or use SlugConfig::default() for Unicode slugs with sensible trimming. The call site is the documentation:

use agent_first_slug::{slugify, AllowedCharacterSet, DotHandlingPolicy,
                       EmptyOutputPolicy, SlugConfig, SlugValidationPolicy,
                       TransliterationPolicy};

// URL path segment: dots preserved in version numbers, empty falls through
let url_config = SlugConfig {
    replacement_delimiter: '-',
    lowercase_enabled: true,
    max_slug_chars: None,
    allowed_character_set: AllowedCharacterSet::UnicodeLettersAndDecimalDigits,
    dot_handling_policy: DotHandlingPolicy::PreserveDotsBetweenDecimalDigits,
    transliteration_policy: TransliterationPolicy::None,
    validation_policy: SlugValidationPolicy::UrlPathSegment,
    empty_output_policy: EmptyOutputPolicy::KeepEmptySlug,
};

assert_eq!(slugify("Ubuntu 16.04", &url_config)?.slug, "ubuntu-16.04");

The same input through a local-path config replaces the dot:

let path_config = SlugConfig {
    dot_handling_policy: DotHandlingPolicy::ReplaceAllDots,
    validation_policy: SlugValidationPolicy::LocalPathSegment,
    empty_output_policy: EmptyOutputPolicy::UseFallbackSlug("fallback".to_string()),
    ..SlugConfig::default()
};

assert_eq!(slugify("Ubuntu 16.04", &path_config)?.slug, "ubuntu-16-04");

What’s in v0.1.0

• Three character sets: ASCII alphanumeric, Unicode alphanumeric, Unicode letters + decimal digits
• Three dot policies: replace all, preserve all, preserve only between decimal digits
• Two validation targets: LocalPathSegment (rejects /, \, ., .., control chars) and UrlPathSegment (additionally rejects ?, #, %, \)
• Two empty-output policies: keep empty or insert a caller-provided fallback verbatim
• Optional transliteration: pass a static replacement map; the library applies it before slugification so legacy romanization tables compose cleanly
• Truncation: max_slug_chars counts Unicode scalar values, strips trailing delimiters after the cut, then applies the empty-output policy
• validate_slug: check a slug you already have against a target policy without slugifying

Unicode is preserved by default, including CJK, kana, and mixed-script inputs:

let config = SlugConfig::default();

assert_eq!(
    slugify("現在的Nobody，未來的Somebody！", &config)?.slug,
    "現在的nobody-未來的somebody"
);

Install

cargo add agent-first-slug

Docs: github.com/agentfirstkit/agent-first-slug