Learning Julia

Macros

Macros in Julia are a very powerful tool for code evaluation, and in some of the previous chapters, we have been using them regularly (for instance, using @time to know the overall compute time of a program).

Macros are similar to functions, but where functions take in normal variables as arguments, macros, on the other hand, take expressions and return modified expressions.

Functions are evaluated at runtime. Macros are evaluated at parse time. This means that macros can manipulate functions (and other code) before they are ever executed.

The syntax of a macro could be defined as follows:

macro NAME
        # some custom code
        # return modified expression
end

At the time of calling a macro, the @ symbol is used, which is used to denote a macro ...