Your Turn
- Exercise: MacrosAndCodeEvaluation-1
Write a macro called myunless that implements the standard unless functionality. You’re allowed to use the regular if expression in it.
- Exercise: MacrosAndCodeEvaluation-2
Write a macro called times_n that takes a single numeric argument. It should define a function called times_n in the caller’s module that itself takes a single argument, and that multiplies that argument by n. So, calling times_n(3) should create a function called times_3, and calling times_3(4) should return 12. Here’s an example of it in use:
defmodule Test do require Times Times.times_n(3) Times.times_n(4) end IO.puts Test.times_3(4) #=> 12 IO.puts Test.times_4(5) #=> 20
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