No release in over a year
A library implementing patterns that behave like regular expressions.


 Project Readme

The Amazing Mustermann

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This repository contains multiple projects (each installable as separate gems).

  • mustermann: Your personal string matching expert. This is probably what you're looking for.
  • mustermann-contrib: A meta gem depending on all other official mustermann gems.
  • mustermann-fileutils: Efficient file system operations using Mustermann patterns.
  • mustermann-strscan: A version of Ruby's StringScanner made for pattern objects.
  • mustermann-visualizer: Syntax highlighting and tree visualization for patterns.'
  • A selection of pattern types for mustermann, each as their own little library, see below.

Git versions with Bundler

You can easily use the latest edge version from GitHub of any of these gems via Bundler:

github 'sinatra/mustermann' do
  gem 'mustermann'
  gem 'mustermann-contrib'

Pattern Types

The identity, regexp and sinatra types are included in the mustermann gem, all the other types have their own gems.

Type Example Compatible with Notes
cake /:prefix/** CakePHP
express /:prefix+/:id(\d+) Express, pillar.js
flask /<prefix>/<int:id> Flask, Werkzeug
identity /image.png any software using strings Exact string matching (no parameter parsing).
pyramid /{prefix:.*}/{id} Pyramid, Pylons
rails /:slug(.:ext) Ruby on Rails, Journey, HTTP Router, Hanami, Scalatra (if configured), NYNY
regexp /(?<slug>[^\/]+) Oniguruma, Onigmo, regular expressions Created when you pass a regexp to
Does not support expanding or generating templates.
shell /*.{png,jpg} Unix Shell (bash, zsh) Does not support expanding or generating templates.
simple /:slug.:ext Sinatra (1.x), Scalatra, Dancer, Finatra, Spark, RCRouter, kick.js Implementation is a direct copy from Sinatra 1.3.
It is the predecessor of sinatra. Does not support expanding or generating templates.
sinatra /:slug(.:ext)? Sinatra (2.x), Padrino (>= 0.13.0), Pendragon, Angelo This is the default and the only type "invented here".
It is a superset of simple and has a common subset with template (and others).
uri-template /{+pre}/{page}{?q} RFC 6570, JSON API, JSON Home Documents and many more Standardized URI templates, can be generated from most other types.

Any software using Mustermann is obviously compatible with at least one of the above.


Mustermann depends on tool (which has been extracted from Mustermann and Sinatra 2.0), and a Ruby 2.6+ compatible Ruby implementation.

JRuby and Rubinius support is unknown.

Release History

Mustermann follows Semantic Versioning 2.0. Anything documented in the README or via YARD and not declared private is part of the public API.

Stable Releases

  • Mustermann 3.0.0 (2022-07-24)

    • Drop support for old Rubies < 2.6.
  • Mustermann 2.0.2 (2022-07-22)

  • Mustermann 2.0.1 (2022-07-19)

  • Mustermann 2.0.0 (2022-07-18)

    • Improve Ruby 3 compatibility. Removed built-in Sinatra 1 support, and moved to new mustermann-sinatra-extension gem. Fixes #114 @epergo
  • Mustermann 1.1.2 (2022-07-16)

  • Mustermann 1.1.1 (2020-01-04)

    • Make sure that requireing ruby2_keywords when needed. Fixes #102 @Annih
  • Mustermann 1.1.0 (2019-12-30)

  • Mustermann 1.0.3 (2018-08-17)

  • Mustermann 1.0.2 (2018-02-17)

  • Mustermann 1.0.1 (2017-08-26)


    • Updating readme to list Ruby 2.2 as minimum commit (@cassidycodes)
    • Fix rendering of HTML table commit (@stevenwilkin)
    • Update summary and description in gemspec file. commit (@junaruga)


    • avoid infinite loop by removing comments when receiving extended regexp commit (@namusyaka)
    • avoid unintended conflict of namespace commit (@namusyaka)
    • use Regexp#source instead of Regexp#inspect commit (@namusyaka)
  • Mustermann 1.0.0 (2017-03-05)

    • First stable release.
    • Includes mustermann, and mustermann-contrib gems
    • Sinatra patterns: Allow | outside of parens.
    • Add concatenation support (Mustermann::Pattern#+).
    • Mustermann::Sinatra#| may now generate a Sinatra pattern instead of a real composite.
    • Add syntax highlighting support for composite patterns.
    • Remove routers (they were out of scope for the main gem).
    • Rails patterns: Add Rails 5.0 compatibility mode, make it default.
    • Moved tool gem EqualityMap to Mustermann::EqualityMap in core
    • Improve documentation.

Development Releases

  • Mustermann 0.4.0 (2014-11-26)
    • More Infos:,,
    • Split into multiple gems.
    • Add Pattern#to_proc.
    • Add Pattern#|, Pattern#& and Pattern#^.
    • Add Pattern#peek, Pattern#peek_size, Pattern#peek_match and Pattern#peek_params.
    • Add Mustermann::StringScanner.
    • Add Pattern#to_templates.
    • Add | syntax to sinatra templates.
    • Add template style placeholders to sinatra templates.
    • Add cake, express, flask and pyramid patterns.
    • Allow passing in additional value behavior directly to Pattern#expand.
    • Fix expanding of multiple splats.
    • Add expanding to identity patterns.
    • Add mustermann-fileutils.
    • Make expander accept hashes with string keys.
    • Allow named splats to be named splat.
    • Support multiple Rails versions.
    • Type option can be set to nil to get the default type.
    • Add mustermann-visualizer.
  • Mustermann 0.3.1 (2014-09-12)
  • Mustermann 0.3.0 (2014-08-18)
    • More Infos:,,
    • Add regexp pattern.
    • Add named splats to Sinatra patterns.
    • Add Mustermann::Mapper.
    • Improve duck typing support.
    • Improve documentation.
  • Mustermann 0.2.0 (2013-08-24)
    • More Infos:,,
    • Add first class expander objects.
    • Add params casting for expander.
    • Add simple router and rack router.
    • Add weak equality map to significantly improve performance.
    • Fix Ruby warnings.
    • Improve documentation.
    • Refactor pattern validation, AST transformations.
    • Increase test coverage (from 100%+ to 100%++).
    • Improve JRuby compatibility.
    • Work around bug in 2.0.0-p0.
  • Mustermann 0.1.0 (2013-05-12)
    • More Infos:,,
    • Add Pattern#expand for generating strings from patterns.
    • Add better internal API for working with the AST.
    • Improved documentation.
    • Avoids parsing the path twice when used as Sinatra extension.
    • Better exceptions for unknown pattern types.
    • Better handling of edge cases around extend.
    • More specs to ensure API stability.
    • Largely rework internals of Sinatra, Rails and Template patterns.
  • Mustermann 0.0.1 (2013-04-27)