Add a Lexer for Bicep language

lib/rouge/demos/bicep

@@ -0,0 +1,10 @@
+targetScope = 'subscription' // To create a resource group
+
+@description('The Azure region to create the resources in.')
+param location string
+
+// Create a resource group
+resource rg 'Microsoft.Resources/resourceGroups@2021-04-01' = {
+  name: 'rg-sample'
+  location: location
+}

lib/rouge/lexers/bicep.rb

@@ -0,0 +1,110 @@
+module Rouge
+  module Lexers
+    class Bicep < Rouge::RegexLexer
+      tag 'bicep'
+      filenames '*.bicep'
+
+      title "Bicep"
+      desc 'Bicep is a domain-specific language (DSL) that uses declarative syntax to deploy Azure resources.'
+
+      def self.keywords
+        @keywords ||= Set.new %w(
+          resource module param var output targetScope dependsOn
+          existing for in if else true false null
+        )
+      end
+
+      def self.datatypes
+        @datatypes ||= Set.new %w(array bool int object string)
+      end
+
+      def self.functions
+        @functions ||= Set.new %w(
+          any array concat contains empty first intersection items last length min max range skip 
+          take union dateTimeAdd utcNow deployment environment loadFileAsBase64 loadTextContent int 
+          json extensionResourceId getSecret list listKeys listKeyValue listAccountSas listSecrets 
+          pickZones reference resourceId subscriptionResourceId tenantResourceId managementGroup 
+          resourceGroup subscription tenant base64 base64ToJson base64ToString dataUri dataUriToString 
+          endsWith format guid indexOf lastIndexOf length newGuid padLeft replace split startsWith 
+          string substring toLower toUpper trim uniqueString uri uriComponent uriComponentToString
+          toObject
+        )
+      end
+
+      operators = %w(+ - * / % < <= > >= == != && || !)
+
+      punctuation = %w(( ) { } [ ] , : ; = .)
+
+      state :root do
+          mixin :comments
+
+          # Match strings
+          rule %r/'/, Str::Single, :string
+
+          # Match numbers
+          rule %r/\b\d+\b/, Num
+
+          # Rules for sets of reserved keywords 
+          rule %r/\b\w+\b/ do |m|
+            if self.class.keywords.include? m[0]
+              token Keyword
+            elsif self.class.datatypes.include? m[0]
+              token Keyword::Type
+            elsif self.class.functions.include? m[0]
+              token Name::Function
+            else
+              token Name
+            end
+          end
+
+          # Match operators
+          rule %r/#{operators.map { |o| Regexp.escape(o) }.join('|')}/, Operator
+
+          # Enter a state when encountering an opening curly bracket
+          rule %r/{/, Punctuation::Indicator, :block
+
+          # Match punctuation
+          rule %r/#{punctuation.map { |p| Regexp.escape(p) }.join('|')}/, Punctuation
+
+          # Match identifiers
+          rule %r/[a-zA-Z_]\w*/, Name
+
+          # Match decorators
+          rule %r/@[a-zA-Z_]\w*/, Name::Decorator
+
+          # Ignore whitespace
+          rule %r/\s+/, Text
+      end
+
+      state :comments do
+        rule %r(//[^\n\r]+), Comment::Single
+        rule %r(/\*.*?\*/)m, Comment::Multiline
+      end
+
+      state :string do
+        rule %r/[^'$}]+/, Str::Single
+        rule %r/\$(?!\{)/, Str::Single
+        rule %r/\$[\{]/, Str::Interpol, :interp
+        rule %r/\'/, Str::Single, :pop!
+        rule %r/\$+/, Str::Single
+      end
+
+      state :interp do
+        rule %r/\}/, Str::Interpol, :pop!
+        mixin :root
+      end
+
+      # State for matching code blocks between curly brackets
+      state :block do
+        # Match property names
+        rule %r/\b([a-zA-Z_]\w*)\b(?=\s*:)/, Name::Property
+
+        # Match closing curly brackets
+        rule %r/}/, Punctuation::Indicator, :pop!
+
+        # Include the root state for nested tokens
+        mixin :root
+      end
+    end
+  end
+end

spec/lexers/bicep_spec.rb

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+# -*- coding: utf-8 -*- #
+# frozen_string_literal: true
+
+describe Rouge::Lexers::Bicep do
+    let(:subject) { Rouge::Lexers::Bicep.new }
+
+    describe 'guessing' do
+      include Support::Guessing
+
+      it 'guesses by filename' do
+        assert_guess :filename => 'foo.bicep'
+        deny_guess   :filename => 'foo'
+      end
+    end
+  end
+

spec/visual/samples/bicep

@@ -0,0 +1,32 @@
+/*
+  Target scope can be set using the following values:
+    - resourceGroup (default)
+    - subscription
+    - managementGroup
+    - tenant
+*/
+targetScope = 'subscription' // To create a resource group
+
+@description('The Azure region to create the resources in.')
+param location string
+
+var suffix = uniqueString(subscription().subscriptionId, 'my-project')
+
+var someTags = [
+  {
+    key: 'location'
+    value: location
+  }
+  {
+    key: 'isTest'
+    value: true
+  }
+]
+
+// Create a resource group
+resource rg 'Microsoft.Resources/resourceGroups@2021-04-01' = {
+  name: 'rg-${suffix}'
+  location: location
+
+  tags: toObject(someTags, tag => tag.key, tag => tag.value)
+}