Lex strings

lib/chervil/lexer.rb

       when ')'
         advance
         Token.new(:rparen, ")")
+      when '"', '\''
+        delimiter = current_char
+        advance
+        string = String.new
+        until current_char == delimiter
+          string << current_char
+          advance
+        end
+
+        if current_char.nil?
+          raise "Unterminated string"
+        end
+
+        advance
+
+        Token.new(:string, string)
       else
         source = @source.slice(@position..-1)
         while source.match(/^\s/)

spec/lexer_spec.rb

         Token.new(:identifier, 'hello')
       )
     end
+
+    it 'lexes strings' do
+      expect(Lexer.new('"hello"').get_next_token).to eq(
+        Token.new(:string, 'hello')
+      )
+      expect(Lexer.new("'world'").get_next_token).to eq(
+        Token.new(:string, 'world')
+      )
+    end
   end
 end