# File lib/rake.rb, line 240
240:     def [](task_name)
241:       task_name = task_name.to_s
242:       if task = TASKS[task_name]
243:         return task
244:       end
245:       if task = enhance_with_matching_rule(task_name)
246:         return task
247:       end
248:       if File.exist?(task_name)
249:         return FileTask.define_task(task_name)
250:       end
251:       fail "Don't know how to build task '#{task_name}'"
252:     end