julia> @resumable function f1()
           [i for i in 1:10 if i<5]
       end
ERROR: LoadError: Illegal expression in generator: i = 1:10 if i < 5
Stacktrace:
 [1] error(s::String)
   @ Base ./error.jl:35
 [2] scope_generator(expr::Expr, scope::ResumableFunctions.ScopeTracker)
   @ ResumableFunctions ~/Documents/ScratchSpace/quantumjulia/ResumableFunctions.jl/src/utils.jl:345
 [3] scoping(expr::Expr, scope::ResumableFunctions.ScopeTracker)
   @ ResumableFunctions ~/Documents/ScratchSpace/quantumjulia/ResumableFunctions.jl/src/utils.jl:361
 [4] scoping(expr::Expr, scope::ResumableFunctions.ScopeTracker) (repeats 2 times)
   @ ResumableFunctions ~/Documents/ScratchSpace/quantumjulia/ResumableFunctions.jl/src/utils.jl:565
 [5] var"@resumable"(__source__::LineNumberNode, __module__::Module, ex::Vararg{Expr})
   @ ResumableFunctions ~/Documents/ScratchSpace/quantumjulia/ResumableFunctions.jl/src/macro.jl:100
in expression starting at REPL[26]:1

julia> @resumable function f2()
           [i for i in 1:10]
       end
f2 (generic function with 1 method)

julia> function f3()
           [i for i in 1:10 if i<5]
       end
f3 (generic function with 1 method)