The Amazing Mustermann - Contrib Edition

This is a meta gem that depends on all mustermann gems.

$ gem install mustermann-contrib
Successfully installed mustermann-1.0.0
Successfully installed mustermann-contrib-1.0.0
...

Also handy for your Gemfile:

gem 'mustermann-contrib'

Alternatively, you can use latest HEAD from github:

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

CakePHP Syntax for Mustermann

This gem implements the cake pattern type for Mustermann. It is compatible with CakePHP 2.x and 3.x.

Overview

Supported options: capture, except, greedy, space_matches_plus, uri_decode, and ignore_unknown_options.

External documentation: CakePHP 2.0 Routing, CakePHP 3.0 Routing

CakePHP patterns feature captures and unnamed splats. Captures are prefixed with a colon and splats are either a single asterisk (parsing segments into an array) or a double asterisk (parsing segments as a single string).

require 'mustermann/cake'

Mustermann.new('/:name/*',  type: :cake).params('/a/b/c') # => { name: 'a', splat: ['b', 'c'] }
Mustermann.new('/:name/**', type: :cake).params('/a/b/c') # => { name: 'a', splat: 'b/c' }

pattern = Mustermann.new('/:name')

pattern.respond_to? :expand # => true
pattern.expand(name: 'foo') # => '/foo'

pattern.respond_to? :to_templates # => true
pattern.to_templates              # => ['/{name}']

Syntax

Syntax Element Description
:name Captures anything but a forward slash in a semi-greedy fashion. Capture is named name. Capture behavior can be modified with capture and greedy option.
* Captures anything in a non-greedy fashion. Capture is named splat. It is always an array of captures, as you can use it more than once in a pattern.
** Captures anything in a non-greedy fashion. Capture is named splat. It is always an array of captures, as you can use it more than once in a pattern. The value matching a single ** will be split at slashes when parsed into params.
/ Matches forward slash. Does not match URI encoded version of forward slash.
any other character Matches exactly that character or a URI encoded version of it.

Express Syntax for Mustermann

This gem implements the express pattern type for Mustermann. It is compatible with Express and pillar.js.

Overview

Supported options: capture, except, greedy, space_matches_plus, uri_decode, and ignore_unknown_options.

External documentation: path-to-regexp, live demo

Express patterns feature named captures (with repetition support via suffixes) that start with a colon and can have an optional regular expression constraint or unnamed captures that require a constraint.

require 'mustermann/express'

Mustermann.new('/:name/:rest+', type: :express).params('/a/b/c') # => { name: 'a', rest: 'b/c' }

pattern = Mustermann.new('/:name', type: :express)

pattern.respond_to? :expand # => true
pattern.expand(name: 'foo') # => '/foo'

pattern.respond_to? :to_templates # => true
pattern.to_templates              # => ['/{name}']

Syntax

Syntax Element Description
:name Captures anything but a forward slash in a semi-greedy fashion. Capture is named name. Capture behavior can be modified with capture and greedy option.
:name+ Captures one or more segments (with segments being separated by forward slashes). Capture is named name. Capture behavior can be modified with capture option.
:name* Captures zero or more segments (with segments being separated by forward slashes). Capture is named name. Capture behavior can be modified with capture option.
:name? Captures anything but a forward slash in a semi-greedy fashion. Capture is named name. Also matches an empty string. Capture behavior can be modified with capture and greedy option.
:name(regexp) Captures anything matching the regexp regular expression. Capture is named name. Capture behavior can be modified with capture.
(regexp) Captures anything matching the regexp regular expression. Capture is named splat. Capture behavior can be modified with capture.
/ Matches forward slash. Does not match URI encoded version of forward slash.
any other character Matches exactly that character or a URI encoded version of it.

FileUtils for Mustermann

This gem implements efficient file system operations for Mustermann patterns.

Globbing

All operations work on a list of files described by one or more pattern.

require 'mustermann/file_utils'

Mustermann::FileUtils[':base.:ext'] # => ['example.txt']

Mustermann::FileUtils.glob(':base.:ext') do |file, params|
  file   # => "example.txt"
  params # => {"base"=>"example", "ext"=>"txt"}
end

To avoid having to loop over all files and see if they match, it will generate a glob pattern resembling the Mustermann pattern as closely as possible.

require 'mustermann/file_utils'

Mustermann::FileUtils.glob_pattern('/:name')                  # => '/*'
Mustermann::FileUtils.glob_pattern('src/:path/:file.(js|rb)') # => 'src/**/*/*.{js,rb}'
Mustermann::FileUtils.glob_pattern('{a,b}/*', type: :shell)   # => '{a,b}/*'

pattern = Mustermann.new('/foo/:page', '/bar/:page') # => #<Mustermann::Composite:...>
Mustermann::FileUtils.glob_pattern(pattern)          # => "{/foo/*,/bar/*}"

Mapping

It is also possible to search for files and have their paths mapped onto another path in one method call:

require 'mustermann/file_utils'

Mustermann::FileUtils.glob_map(':base.:ext' => ':base.bak.:ext') # => {'example.txt' => 'example.bak.txt'}
Mustermann::FileUtils.glob_map(':base.:ext' => :base) { |file, mapped| mapped } # => ['example']

This mechanism allows things like copying, renaming and linking files:

require 'mustermann/file_utils'

# copies example.txt to example.bak.txt
Mustermann::FileUtils.cp(':base.:ext' => ':base.bak.:ext')

# copies Foo.app/example.txt to Foo.back.app/example.txt
Mustermann::FileUtils.cp_r(':base.:ext' => ':base.bak.:ext')

# creates a symbolic link from bin/example to lib/example.rb
Mustermann::FileUtils.ln_s('lib/:name.rb' => 'bin/:name')

Flask Syntax for Mustermann

This gem implements the flask pattern type for Mustermann. It is compatible with Flask and Werkzeug.

Overview

Supported options: capture, except, greedy, space_matches_plus, uri_decode, converters and ignore_unknown_options

External documentation: Werkzeug: URL Routing

require 'mustermann/flask'

Mustermann.new('/<prefix>/<path:page>', type: :flask).params('/a/b/c') # => { prefix: 'a', page: 'b/c' }

pattern = Mustermann.new('/<name>', type: :flask)

pattern.respond_to? :expand # => true
pattern.expand(name: 'foo') # => '/foo'

pattern.respond_to? :to_templates # => true
pattern.to_templates              # => ['/{name}']

Syntax

Syntax Element Description
<name> Captures anything but a forward slash in a semi-greedy fashion. Capture is named name. Capture behavior can be modified with capture and greedy option.
<converter:name> Captures depending on the converter constraint. Capture is named name. Capture behavior can be modified with capture and greedy option. See below.
<converter(arguments):name> Captures depending on the converter constraint. Capture is named name. Capture behavior can be modified with capture and greedy option. Arguments are separated by comma. An argument can be a simple string, a string enclosed in single or double quotes, or a key value pair (keys and values being separated by an equal sign). See below.
/ Matches forward slash. Does not match URI encoded version of forward slash.
any other character Matches exactly that character or a URI encoded version of it.

Converters

Builtin Converters

string

Possible arguments: minlength, maxlength, length

Captures anything but a forward slash in a semi-greedy fashion. Capture behavior can be modified with capture and greedy option.

This is also the default converter.

Examples:

<name>
<string:name>
<string(minlength=3,maxlength=10):slug>
<string(length=10):slug>

int

Possible arguments: min, max, fixed_digits

Captures digits. Captured value will be converted to an Integer.

Examples:

<int:id>
<int(min=1,max=5):page>
<int(fixed_digits=16):uuid>

float

Possible arguments: min, max

Captures digits with a dot. Captured value will be converted to an Float.

Examples:

<float:precision>
<float(min=0,max=1):precision>

path

Captures anything in a non-greedy fashion.

Example:

<path:rest>

any

Possible arguments: List of accepted strings.

Captures anything that matches one of the arguments exactly.

Example:

<any(home,search,contact):page>

Custom Converters

Flask patterns support registering custom converters.

A converter object may implement any of the following methods:

  • convert: Should return a block converting a string value to whatever value should end up in the params hash.
  • constraint: Should return a regular expression limiting which input string will match the capture.
  • new: Returns an object that may respond to convert and/or constraint as described above. Any arguments used for the converter inside the pattern will be passed to new.
require 'mustermann/flask'

SimpleConverter = Struct.new(:constraint, :convert)
id_converter    = SimpleConverter.new(/\d/, -> s { s.to_i })

class NumConverter
  def initialize(base: 10)
    @base = Integer(base)
  end

  def convert
    -> s { s.to_i(@base) }
  end

  def constraint
    @base > 10 ? /[\da-#{(@base-1).to_s(@base)}]/ : /[0-#{@base-1}]/
  end
end

pattern = Mustermann.new('/<id:id>/<num(base=8):oct>/<num(base=16):hex>',
  type: :flask, converters: { id: id_converter, num: NumConverter})

pattern.params('/10/12/f1') # => {"id"=>10, "oct"=>10, "hex"=>241}

Global Converters

It is also possible to register a converter for all flask patterns, using register_converter:

Mustermann::Flask.register_converter(:id,  id_converter)
Mustermann::Flask.register_converter(:num, NumConverter)

pattern = Mustermann.new('/<id:id>/<num(base=8):oct>/<num(base=16):hex>', type: :flask)
pattern.params('/10/12/f1') # => {"id"=>10, "oct"=>10, "hex"=>241}

There is a handy syntax for quickly creating new converter classes: When you pass a block instead of a converter object, it will yield a generic converter with setters and getters for convert and constraint, and any arguments passed to the converter.

require 'mustermann/flask'

Mustermann::Flask.register_converter(:id) do |converter|
  converter.constraint = /\d/
  converter.convert    = -> s { s.to_i }
end

Mustermann::Flask.register_converter(:num) do |converter, base: 10|
  converter.constraint = base > 10 ? /[\da-#{(@base-1).to_s(base)}]/ : /[0-#{base-1}]/
  converter.convert    = -> s { s.to_i(base) }
end

pattern = Mustermann.new('/<id:id>/<num(base=8):oct>/<num(base=16):hex>', type: :flask)
pattern.params('/10/12/f1') # => {"id"=>10, "oct"=>10, "hex"=>241}

Subclassing

Registering global converters will make these available for all Flask patterns. It might even override already registered converters. This global state might break unrelated code.

It is therefore recommended that, if you don't want to pass in the converters option for every pattern, you create your own subclass of Mustermann::Flask.

require 'mustermann/flask'

MyFlask = Class.new(Mustermann::Flask)

MyFlask.register_converter(:id) do |converter|
  converter.constraint = /\d/
  converter.convert    = -> s { s.to_i }
end

MyFlask.register_converter(:num) do |converter, base: 10|
  converter.constraint = base > 10 ? /[\da-#{(@base-1).to_s(base)}]/ : /[0-#{base-1}]/
  converter.convert    = -> s { s.to_i(base) }
end

pattern = MyFlask.new('/<id:id>/<num(base=8):oct>/<num(base=16):hex>')
pattern.params('/10/12/f1') # => {"id"=>10, "oct"=>10, "hex"=>241}

You can even register this type for usage with Mustermann.new:

Mustermann.register(:my_flask, MyFlask)
pattern = Mustermann.new('/<id:id>/<num(base=8):oct>/<num(base=16):hex>', type: :my_flask)
pattern.params('/10/12/f1') # => {"id"=>10, "oct"=>10, "hex"=>241}

Pyramid Syntax for Mustermann

This gem implements the pyramid pattern type for Mustermann. It is compatible with Pyramid and Pylons.

Overview

Supported options: capture, except, greedy, space_matches_plus, uri_decode and ignore_unknown_options

External Documentation: Pylons Framework: URL Configuration, Pylons Book: Routes in Detail, Pyramid: Route Pattern Syntax

require 'mustermann/pyramid'

Mustermann.new('/{prefix}/*suffix', type: :pyramid).params('/a/b/c') # => { prefix: 'a', suffix: ['b', 'c'] }

pattern = Mustermann.new('/{name}', type: :pyramid)

pattern.respond_to? :expand # => true
pattern.expand(name: 'foo') # => '/foo'

pattern.respond_to? :to_templates # => true
pattern.to_templates              # => ['/{name}']

Syntax

Syntax Element Description
{name} Captures anything but a forward slash in a semi-greedy fashion. Capture is named name. Capture behavior can be modified with capture and greedy option.
{name:regexp} Captures anything matching the regexp regular expression. Capture is named name. Capture behavior can be modified with capture.
*name Captures anything in a non-greedy fashion. Capture is named name.
/ Matches forward slash. Does not match URI encoded version of forward slash.
any other character Matches exactly that character or a URI encoded version of it.

Rails Syntax for Mustermann

This gem implements the rails pattern type for Mustermann. It is compatible with Ruby on Rails, Journey, the http_router gem, Lotus and Scalatra (if configured)

Overview

Supported options: capture, except, greedy, space_matches_plus, uri_decode, version, and ignore_unknown_options.

External documentation: Ruby on Rails Guides: Routing.

require 'mustermann'

pattern = Mustermann.new('/:example', type: :rails)
pattern === "/foo.bar"     # => true
pattern === "/foo/bar"     # => false
pattern.params("/foo.bar") # => { "example" => "foo.bar" }
pattern.params("/foo/bar") # => nil

pattern = Mustermann.new('/:example(/:optional)', type: :rails)
pattern === "/foo.bar"     # => true
pattern === "/foo/bar"     # => true
pattern.params("/foo.bar") # => { "example" => "foo.bar", "optional" => nil   }
pattern.params("/foo/bar") # => { "example" => "foo",     "optional" => "bar" }

pattern = Mustermann.new('/*example', type: :rails)
pattern === "/foo.bar"     # => true
pattern === "/foo/bar"     # => true
pattern.params("/foo.bar") # => { "example" => "foo.bar" }
pattern.params("/foo/bar") # => { "example" => "foo/bar" }

Rails Compatibility

Rails syntax changed over time. You can target different Ruby on Rails versions by setting the version option to the desired Rails version.

The default is 4.2. Versions prior to 2.3 are not supported.

require 'mustermann'
Mustermann.new('/', type: :rails, version: "2.3")
Mustermann.new('/', type: :rails, version: "3.0.0")

require 'rails'
Mustermann.new('/', type: :rails, version: Rails::VERSION::STRING)

Syntax

Syntax Element Description
:name Captures anything but a forward slash in a semi-greedy fashion. Capture is named name. Capture behavior can be modified with tt>capture and greedy option.
*name Captures anything in a non-greedy fashion. Capture is named name.
(expression) Enclosed expression is optional. Not available in 2.3 compatibility mode.
/ Matches forward slash. Does not match URI encoded version of forward slash.
\x In 3.x compatibility mode and starting with 4.2: Matches x or URI encoded version of x. For instance \* matches *.
In 4.0 or 4.1 compatibility mode: \ is ignored, x is parsed normally.
expression | expression 3.2+ mode: This will raise a `Mustermann::ParseError`. While Ruby on Rails happily parses this character, it will result in broken routes due to a buggy implementation.
5.0 mode: It will match if any of the nested expressions matches.
any other character Matches exactly that character or a URI encoded version of it.

Shell Syntax for Mustermann

This gem implements the shell pattern type for Mustermann. It is compatible with common Unix shells (like bash or zsh).

Overview

Supported options: uri_decode and ignore_unknown_options.

External documentation: Ruby's fnmatch, Wikipedia: Glob (programming)

require 'mustermann'

pattern = Mustermann.new('/*', type: :shell)
pattern === "/foo.bar" # => true
pattern === "/foo/bar" # => false

pattern = Mustermann.new('/**/*', type: :shell)
pattern === "/foo.bar" # => true
pattern === "/foo/bar" # => true

pattern = Mustermann.new('/{foo,bar}', type: :shell)
pattern === "/foo"     # => true
pattern === "/bar"     # => true
pattern === "/baz"     # => false

Syntax

Syntax Element Description
* Matches anything but a slash.
** Matches anything.
[set] Matches one character in set.
{a,b} Matches a or b.
\x Matches x or URI encoded version of x. For instance \* matches *.
any other character Matches exactly that character or a URI encoded version of it.

Simple Syntax for Mustermann

This gem implements the simple pattern type for Mustermann. It is compatible with Sinatra (1.x), Scalatra and Dancer.

Overview

Supported options: greedy, space_matches_plus, uri_decode and ignore_unknown_options.

This is useful for porting an application that relies on this behavior to a later Sinatra version and to make sure Sinatra 2.0 patterns do not decrease performance. Simple patterns internally use the same code older Sinatra versions used for compiling the pattern. Error messages for broken patterns will therefore not be as informative as for other pattern implementations.

require 'mustermann'

pattern = Mustermann.new('/:example', type: :simple)
pattern === "/foo.bar"     # => true
pattern === "/foo/bar"     # => false
pattern.params("/foo.bar") # => { "example" => "foo.bar" }
pattern.params("/foo/bar") # => nil

pattern = Mustermann.new('/:example/?:optional?', type: :simple)
pattern === "/foo.bar"     # => true
pattern === "/foo/bar"     # => true
pattern.params("/foo.bar") # => { "example" => "foo.bar", "optional" => nil   }
pattern.params("/foo/bar") # => { "example" => "foo",     "optional" => "bar" }

pattern = Mustermann.new('/*', type: :simple)
pattern === "/foo.bar"     # => true
pattern === "/foo/bar"     # => true
pattern.params("/foo.bar") # => { "splat" => ["foo.bar"] }
pattern.params("/foo/bar") # => { "splat" => ["foo/bar"] }

Syntax

Syntax Element Description
:name Captures anything but a forward slash in a greedy fashion. Capture is named name.
* Captures anything in a non-greedy fashion. Capture is named splat. It is always an array of captures, as you can use * more than once in a pattern.
x? Makes x optional. For instance foo? matches foo or fo.
/ Matches forward slash. Does not match URI encoded version of forward slash.
any special character Matches exactly that character or a URI encoded version of it.
any other character Matches exactly that character.

String Scanner for Mustermann

This gem implements Mustermann::StringScanner, a tool inspired by Ruby's StringScanner class.

require 'mustermann/string_scanner'
scanner = Mustermann::StringScanner.new("here is our example string")

scanner.scan("here") # => "here"
scanner.getch        # => " "

if scanner.scan(":verb our")
  scanner.scan(:noun, capture: :word)
  scanner[:verb]  # => "is"
  scanner[:nound] # => "example"
end

scanner.rest # => "string"

You can pass it pattern objects directly:

pattern = Mustermann.new(':name')
scanner.check(pattern)

Or have #scan (and other methods) check these for you.

scanner.check('{name}', type: :template)

You can also pass in default options for ad hoc patterns when creating the scanner:

scanner = Mustermann::StringScanner.new(input, type: :shell)

URI Template Syntax for Mustermann

This gem implements the uri-template (or template) pattern type for Mustermann. It is compatible with RFC 6570 (level 4), JSON API, JSON Home Documents and many more

Overview

Supported options: capture, except, greedy, space_matches_plus, uri_decode, and ignore_unknown_options.

Please keep the following in mind:

"Some URI Templates can be used in reverse for the purpose of variable matching: comparing the template to a fully formed URI in order to extract the variable parts from that URI and assign them to the named variables. Variable matching only works well if the template expressions are delimited by the beginning or end of the URI or by characters that cannot be part of the expansion, such as reserved characters surrounding a simple string expression. In general, regular expression languages are better suited for variable matching." — RFC 6570, Sec 1.5: "Limitations"

require 'mustermann'

pattern = Mustermann.new('/{example}', type: :template)
pattern === "/foo.bar"     # => true
pattern === "/foo/bar"     # => false
pattern.params("/foo.bar") # => { "example" => "foo.bar" }
pattern.params("/foo/bar") # => nil

pattern = Mustermann.new("{/segments*}/{page}{.ext,cmpr:2}", type: :template)
pattern.params("/a/b/c.tar.gz") # => {"segments"=>["a","b"], "page"=>"c", "ext"=>"tar", "cmpr"=>"gz"}

Generating URI Templates

You do not need to use URI templates (and this gem) if all you want is reusing them for hypermedia links. Most other pattern types support generating these (via #to_pattern):

require 'mustermann'

Mustermann.new('/:name').to_templates # => ['/{name}']

Moreover, Mustermann's default pattern type implements a subset of URI templates (capture and +capture) and can therefore also be used for simple templates/

require 'mustermann'

Mustermann.new('/{name}').expand(name: "example") # => "/example"

Syntax

Syntax Element Description
{o var m, var m, ...} Captures expansion. Operator o: + # . / ; ? & or none. Modifier m: :num * or none.
/ Matches forward slash. Does not match URI encoded version of forward slash.
any other character Matches exactly that character or a URI encoded version of it.

The operators + and # will always match non-greedy, whereas all other operators match semi-greedy by default. All modifiers and operators are supported. However, it does not parse lists as single values without the explode modifier (aka star). Parametric operators (;, ? and &) currently only match parameters in given order.

Note that it differs from URI templates in that it takes the unescaped version of special character instead of the escaped version.

If you reuse the exact same templates and expose them via an external API meant for expansion, you should set uri_decode to false in order to conform with the specification.

Mustermann Pattern Visualizer

With this gem, you can visualize the internal structure of a Mustermann pattern:

  • You can generate a syntax highlighted version of a pattern object. Both HTML/CSS based highlighting and ANSI color code based highlighting is supported.
  • You can turn a pattern object into a tree (with ANSI color codes) representing the internal AST. This of course only works for AST based patterns.

Syntax Highlighting

Loading mustermann/visualizer will automatically add to_html and to_ansi to pattern objects.

require 'mustermann/visualizer'
puts Mustermann.new('/:name').to_ansi
puts Mustermann.new('/:name').to_html

Alternatively, you can also create a separate highlight object, which allows finer grained control and more formats:

require 'mustermann/visualizer'

pattern   = Mustermann.new('/:name')
highlight = Mustermann::Visualizer.highlight(pattern)

puts highlight.to_ansi

inspect mode

By default, the highlighted string will be a colored version of to_s. It is also possible to produce a colored version of inspect

require 'mustermann/visualizer'

pattern = Mustermann.new('/:name')

# directly from the pattern
puts pattern.to_ansi(inspect: true)

# via the highlighter
highlight = Mustermann::Visualizer.highlight(pattern, inspect: true)
puts highlight.to_ansi

Themes

element inherits style from default theme note
default #839496 ANSI \e[10m if not set
special default #268bd2
capture special #cb4b16
name #b58900 always inside capture
char default
expression capture only exists in URI templates
composition special meta style, does not exist directly
composite composition used for composite patterns (contains roots)
group composition
union composition
optional special
root default wraps the whole pattern
separator char #93a1a1
splat capture
named_splat splat
variable capture always inside expression
escaped char #93a1a1
escaped_char always inside escaped
quote special #dc322f always outside of root
type special always inside composite, outside of root
illegal special #8b0000

You can set theme any of the above elements. The default theme will only be applied if no custom theming is used.

# custom theme with highlight object
highlight = Mustermann::Visualizer.highlight(pattern, special: "#08f")
puts highlight.to_ansi

Themes apply both to ANSI and to HTML/CSS output. The exact ANSI code used depends on the terminal and its capabilities.

HTML and CSS

By default, the syntax elements will be translated into span tags with style attributes.

Mustermann.new('/:name').to_html
<span style="color: #839496;"><span style="color: #93a1a1;">/</span><span style="color: #cb4b16;">:<span style="color: #b58900;">name</span></span></span></span>

You can also set the css option to true to make it include a stylesheet instead.

Mustermann.new('/:name').to_html(css: true)
<span class="mustermann_pattern"><style type="text/css">
.mustermann_pattern .mustermann_name {
  color: #b58900;
}
/* ... etc ... */
</style><span class="mustermann_root"><span class="mustermann_separator">/</span><span class="mustermann_capture">:<span class="mustermann_name">name</span></span></span></span>

Or you can set it to false, which will omit style attributes, but include class attributes.

<span class="mustermann_pattern"><span class="mustermann_root"><span class="mustermann_separator">/</span><span class="mustermann_capture">:<span class="mustermann_name">name</span></span></span></span>

It is possible to change the class prefix and the tag used.

Mustermann.new('/:name').to_html(css: false, class_prefix: "mm_", tag: "tt")
<tt class="mm_pattern"><tt class="mm_root"><tt class="mm_separator">/</tt><tt class="mm_capture">:<tt class="mm_name">name</tt></tt></tt></tt>

If you create a highlight object, you can ask it for its stylesheet.

<% highlight = Mustermann::Visualizer.highlight("/:name") %>

<html>
  <head>
    <style type="text/css">
      <%= highlight.stylesheet %>
    </style>
  </head>
  <body>
    <%= highlight.to_html(css: false) %>
  </body>
</html>

Other formats

If you create a highlight object, you have two other formats available: Hansi template strings and s-expression like strings. These might be useful if you want to check how a theme will be applied or as intermediate format for highlighting by other means.

require 'mustermann/visualizer'
highlight = Mustermann::Visualizer.highlight("/:page")
puts highlight.to_hansi_template
puts highlight.to_sexp

Hansi template strings wrap elements in tags that are similar to XML tags (though they are not, entity encoding and attributes are not supported, escaping works with a slash, so an escaped > would be \>, not &gt;).

<pattern><root><separator>/</separator><capture>:<name>page</name></capture></root></pattern>

The s-expression like syntax looks as follows:

(root (separator /) (capture : (name page)))
  • An expression is enclosed by parens and contains elements separated by spaces. The first element in the expression type (corresponding to themeable elements). These are simple strings. The other elements are either expressions, simple strings or full strings.
  • Simple strings do not contain spaces, parens, single or double quotes or any character that needs to be escaped.
  • Full strings are Ruby strings enclosed by double quotes.
  • Spaces before or after parens are optional.

IRB/Pry integration

When mustermann is being loaded from within an IRB or Pry session, it will automatically load mustermann/visualizer too, if possible. When displayed as result, it will be highlighted.

In Pry, this will even work when nested inside other objects (like as element on an array).

Tree Rendering

Loading mustermann/visualizer will automatically add to_tree to pattern objects.

require 'mustermann/visualizer'
puts Mustermann.new("/:page(.:ext)?/*action").to_tree

For patterns not based on an AST (shell, simple, regexp), it will print out a single line:

pattern (not AST based)  "/example"

It will display a tree for identity patterns. While these are not based on an AST internally, Mustermann supports generating an AST for these patterns.