Now that’s brilliant! Thanks!
For other beginners here the full solution:
using JuliaParser
src = """
function fun(n::Int)
s = 2 * n
println(s)
end
"""
ast = Parser.parse(src);
Meta.show_sexpr(ast)
funbody = [string(subex) for subex in ast.args[2].args if subex.head != :line]
print(funbody)