Julia Metaprogramming

julia_meta.jl

julia> for sym in (:foo, :baz, :bar)
           #=
             $ is used to interpolate expressions (`Expr`) and symbols into other expressions
             it is also used to interpolate values in strings and commands (`Cmd`)
           =#
           @eval $(sym)() = println($"$sym was called")
       end

julia> syms = [symbol(string(:test, i)) for i in 1:5]    # generate symbols
5-element Array{Symbol,1}:
 :test1
 :test2
 :test3
 :test4
 :test5

julia> for sym in syms
           @eval $(sym)() = println($"$sym was called")    # function definitions
       end

julia> for sym in syms
           @eval $sym()    # function calls
       end
test1 was called
test2 was called
test3 was called
test4 was called
test5 was called

julia> dump(    # the expression AST
           quote
               for sym in syms
                   @eval $(sym)() = println($"$sym was called")
               end
           end
       )
Expr
  head: Symbol block
  args: Array(Any,(2,))
    1: Expr
      head: Symbol line
      args: Array(Any,(2,))
        1: Int32 3
        2: Symbol none
      typ: Any
    2: Expr
      head: Symbol for
      args: Array(Any,(2,))
        1: Expr
          head: Symbol =
          args: Array(Any,(2,))
          typ: Any
        2: Expr
          head: Symbol block
          args: Array(Any,(2,))
          typ: Any
      typ: Any
  typ: Any