T

Macros for seeing where and when things are happening in a concurrent framwork.

Example program:

require "./method_name_macro"
# extend T # extend or include at the top level is possible

T.trace = true

module Foo
  include T

  def self.foo
    d # just method name prints
    dt "no parentheses seems neatest"
    dt "before sleep"
    sleep 750.milliseconds
    dt("after three quarter second sleep")
    d "bottom" # just method name and message, no time
  end
end

Foo.foo
T.dtt("at top level (no method name available)")

At the prompt:

$ crystal try_name_macros.cr
         :  foo :
  0.000  :  foo : no parentheses seems neatest
  0.000  :  foo : before sleep
  0.750  :  foo : after three quarter second sleep
         :  foo : bottom
  0.751  :  at top level (no method name available)

The module has global like class variables start and trace. start is set to the time the program started, and trace should be set to true if trace statements placed in the program text should actually print something. By using macro instead of def, the macro is inlined so we get the method name the macro is in.