Make hashes their own token type

lib/ahem/ast/operators.rb

   OR = :or
   AND = :and
   NOT = :not
-  HASH = :'#'
 end

lib/ahem/lexer.rb

     elsif source.match(/\A=>/)
       @position += 2
       Token.new(TokenKinds::ROCKET)
+    elsif source.match(/\A\#/)
+      @position += 1
+      Token.new(TokenKinds::HASH)      
     elsif source.match(/\A!/)
       @position += 1
       Token.new(TokenKinds::OPERATOR, :!)
     elsif source.match(/\A\>/)
       @position += 1
       Token.new(TokenKinds::OPERATOR, :>)
-    elsif source.match(/\A\#/)
-      @position += 1
-      Token.new(TokenKinds::OPERATOR, :'#')
     elsif source.match(/\Aand/)
       @position += 3
       Token.new(TokenKinds::OPERATOR, :and)

lib/ahem/token_kinds.rb

   EQUALS = :equals
   FOR = :for
   FUNCTION = :function
+  HASH = :hash
   IDENTIFIER = :identifier
   IF = :if
   IN = :in

spec/lexer_spec.rb

   end
 
   it 'lexes operators' do
-    expect(Lexer.new('+-*/<<=>>===# and or not').scan_all).to eq(
+    expect(Lexer.new('+-*/<<=>>=== and or not').scan_all).to eq(
       [
         Token.new(TokenKinds::OPERATOR, :+),
         Token.new(TokenKinds::OPERATOR, :-),
         Token.new(TokenKinds::OPERATOR, :>),
         Token.new(TokenKinds::OPERATOR, :>=),
         Token.new(TokenKinds::OPERATOR, :==),
-        Token.new(TokenKinds::OPERATOR, :'#'),
         Token.new(TokenKinds::OPERATOR, :and),
         Token.new(TokenKinds::OPERATOR, :or),
         Token.new(TokenKinds::OPERATOR, :not),
       ]
     )
   end
+
+  it 'lexes hashes' do
+    expect(Lexer.new("#").scan_all).to eq(
+      [
+        Token.new(TokenKinds::HASH),
+        Token.new(TokenKinds::EOF)
+      ]
+    )
+  end
 end