Add new filehash.rb linguist.rb and math.rb plugins

Author: tmthrgd

README.md

@@ -1,5 +1,11 @@
 Custom plugins for the Jekyll static site generator.
 
+## filehash.rb
+
+filehash.rb generates a SHA1 hex digest for a given file.
+
+It has no dependencies.
+
 ## h1kramdown.rb
 
 h1kramdown.rb patches `Kramdown::Converter::Html.convert_header` so that it inserts an empty `a` element as the first child of h[1..6] elements, with href pointing to the id of the h[1..6] element. It can be styled with the selector `h[1..6] > a:first-child:empty`.
@@ -14,6 +20,21 @@ handleize.rb is a liquid filter that forms a valid handle/slug from an input str
 
 It has no dependencies.
 
+## linguist.rb
+
+linguist.rb contains the tag `linguist_colors` that outputs css rules corresponding to languages that [linguist](https://github.com/github/linguist) (used by GitHub) detects.
+
+It depends on linguist: `$ [sudo] gem install github-linguist`.
+
+It accepts a property to assign the colour to and a css selector that replaces the `{language}` token with a slug derived from the language name.
+
+## math.rb
+
+math.rb provides liquid filters to access the following [`Math` module](http://www.ruby-doc.org/core-1.9.3/Math.html) methods: [acos](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-acos) [acosh](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-acosh) [asin](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-asin) [asinh](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-asinh) [atan](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-atan) [atan2](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-atan2) [atanh](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-atanh) [cbrt](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-cbrt) [cos](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-cos) [cosh](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-cosh) [erf](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-erf) [erfc](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-erfc) [exp](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-exp) [frexp](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-frexp) [gamma](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-gamma) [hypot](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-hypot) [ldexp](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-ldexp) [lgamma](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-lgamma) [log](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-log) [log10](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-log10) [log2](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-log2) [sin](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-sin) [sinh](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-sinh) [sqrt](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-sqrt) [tan](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-tan) [tanh](http://www.ruby-doc.org/core-1.9.3/Math.html#method-c-tanh).
+It also provides filters to access the following [`Numeric` module](http://ruby-doc.org/core-1.9.3/Numeric.html) methods: [abs](http://ruby-doc.org/core-1.9.3/Numeric.html#method-i-abs) [abs2](http://ruby-doc.org/core-1.9.3/Numeric.html#method-i-abs2) [divmod](http://ruby-doc.org/core-1.9.3/Numeric.html#method-i-divmod) [remainder](http://ruby-doc.org/core-1.9.3/Numeric.html#method-i-remainder).
+
+It has no dependencies.
+
 ## mathml.rb
 
 mathml.rb converts TeX into MathML. It provides a liquid tag `math` (and closing tag `endmath`), TeX within the tag will be converted into MathML. If kramdown is installed it will also replace `Kramdown::Converter::Html.convert_math` so that MathML can be generated using kramdown builtins. To clarify you can always use `{% math %}...{% endmath %}` but when using the kramdown parser you can also use `$$...$$`.

filehash.rb

@@ -0,0 +1,9 @@
+require "digest/sha1"
+
+module Jekyll::FileHash
+	def file_hash input
+		Digest::SHA1.hexdigest IO.read input
+	end
+end
+
+Liquid::Template.register_filter Jekyll::FileHash

linguist.rb

@@ -0,0 +1,24 @@
+require "linguist"
+
+class Jekyll::Tags::LinguistColors < Liquid::Tag
+	def initialize tag_name, markup, tokens
+		@attributes = {
+			:selector => ".language-{language}",
+			:property => "background"
+		}
+		
+		markup.scan(Liquid::TagAttributes) { |key, value| @attributes[key.to_sym] = value }
+		
+		super
+	end
+	
+	def render context
+		Linguist::Language.all.select{ |language| language.color }.map do |language|
+			slug = language.name.gsub(/\s+/, "-").gsub(/([#+])/, "\\\\\\\\\\1").downcase
+			
+			"#{@attributes[:selector].gsub "{language}", slug} { #{@attributes[:property]}: #{language.color} }"
+		end * "\n"
+	end
+end
+
+Liquid::Template.register_tag "linguist_colors", Jekyll::Tags::LinguistColors

math.rb

@@ -0,0 +1,17 @@
+module Jekyll::MathFilter
+	%w[acos acosh asin asinh atan atan2 atanh cbrt cos cosh erf erfc
+		exp frexp gamma hypot ldexp lgamma log log10 log2 sin sinh
+		sqrt tan tanh].each do |name|
+		define_method name.to_sym do |*args|
+			Math.send name, *args
+		end
+	end
+	
+	%w[abs abs2 divmod remainder].each do |name|
+		define_method name.to_sym do |input, *args|
+			input.send name, *args
+		end
+	end
+end
+
+Liquid::Template.register_filter Jekyll::MathFilter