Benchmarktools' belapsed not working on symbol - julia

Question

Introduction
I have a directory with the following structure
--> Report
--> Problems
--> PE_001
--> Julia
PE_001.naive.jl
PE_001.jl
--> Benchmarks
test_001.txt
test_002.txt
--> Results
--> PE_002
.
.
.
--> PE_XXX
--> Benchmark
I am attempting to iterate over all the Julia files and benchmark them against the benchmarking data located under the top directory Benchmark. I do not want to have to cd into each directory and run # belapsed from the julia commandline to time every function individually.
To solve this problem I wrote the following code that is supposed to be located under benchmarks in the hierachy above. However I made it slightly simpler for illustrative purposes.
Attempt at solution
EDIT: The code below does NOT follow the hierarchy outlined above. To quickly reproduce the error, the code below has been written in such a way that all the files can be placed in the same directory.
benchmark.jl
include("PE_002.jl")
using BenchmarkTools
function get_file_path(PE=1)
current_folder = pwd()
PE_folder = "/PE_" * lpad(string(PE),3,"0")
dirname(pwd()) * "/Problems" * PE_folder * "/Julia"
end
function include_files(PE_dir)
for filename in readdir(PE_dir)
if !startswith(filename, "benchmark")
filepath = PE_dir * "/" * filename
#everywhere include($filepath)
end
end
end
function benchmark_files(PE_dir)
for filename in readdir(PE_dir)
if !startswith(filename, "benchmark")
f = getfield(Main, Symbol(filename[1:end-3]))
# Produces an error
println(#belapsed f())
end
end
end
# Works
println(#belapsed PE_002())
PE_dir = pwd()
include_files(PE_dir)
benchmark_files(PE_dir)
PE_002.jl
function PE_002(limit = 4*10^6)
a, b = 0, 2
while b < limit
a, b = b, 4 * b + a
end
div(a + b - 2, 4)
end
PE_002_naive.jl
function PE_002_naive(limit=4 * 10^6, F_1=1, F_2=2)
total = 0
while F_2 < limit
if F_2 % 2 == 0
total += F_2
end
F_1, F_2 = F_2, F_1 + F_2
end
total
end
test_001.txt
0*10**(2**0)
4*10**(2**0)
4*10**(2**1)
4*10**(2**2)
4*10**(2**3)
4*10**(2**4)
4*10**(2**5)
4*10**(2**6)
Question
Interestingly enough including the file PE_002 and then running # belapsed works, however obtaining the filename from the directory, turning it into a symbol, then trying to time it with #belapsed fails.
I know #elapsed works, however, due to garbage collection it is not nearly accurate enough for my needs.
Is there a simple way to benchmark all files in a remote directory using BenchmarkTools or similar tools as accurate?
All I need is a single number representing mean / average running time from each file.
EDIT 2: Per request I have included the full error message below
~/P/M/Julia-belaps ❯❯❯ julia benchmark.jl
9.495495495495496e-9
ERROR: LoadError: UndefVarError: f not defined
Stacktrace:
[1] ##core#665() at /home/oisov/.julia/v0.6/BenchmarkTools/src/execution.jl:290
[2] ##sample#666(::BenchmarkTools.Parameters) at /home/oisov/.julia/v0.6/BenchmarkTools/src/execution.jl:296
[3] #_run#6(::Bool, ::String, ::Array{Any,1}, ::Function, ::BenchmarkTools.Benchmark{Symbol("##benchmark#664")}, ::BenchmarkTools.Parameters) at /home/oisov/.julia/v0.6/BenchmarkTools/src/execution.jl:324
[4] (::BenchmarkTools.#kw##_run)(::Array{Any,1}, ::BenchmarkTools.#_run, ::BenchmarkTools.Benchmark{Symbol("##benchmark#664")}, ::BenchmarkTools.Parameters) at ./<missing>:0
[5] anonymous at ./<missing>:?
[6] #run_result#16(::Array{Any,1}, ::Function, ::BenchmarkTools.Benchmark{Symbol("##benchmark#664")}, ::BenchmarkTools.Parameters) at /home/oisov/.julia/v0.6/BenchmarkTools/src/execution.jl:40
[7] (::BenchmarkTools.#kw##run_result)(::Array{Any,1}, ::BenchmarkTools.#run_result, ::BenchmarkTools.Benchmark{Symbol("##benchmark#664")}, ::BenchmarkTools.Parameters) at ./<missing>:0
[8] #run#17(::Array{Any,1}, ::Function, ::BenchmarkTools.Benchmark{Symbol("##benchmark#664")}, ::BenchmarkTools.Parameters) at /home/oisov/.julia/v0.6/BenchmarkTools/src/execution.jl:43
[9] (::Base.#kw##run)(::Array{Any,1}, ::Base.#run, ::BenchmarkTools.Benchmark{Symbol("##benchmark#664")}, ::BenchmarkTools.Parameters) at ./<missing>:0 (repeats 2 times)
[10] macro expansion at /home/oisov/.julia/v0.6/BenchmarkTools/src/execution.jl:208 [inlined]
[11] benchmark_files(::String) at /home/oisov/Programming/Misc/Julia-belaps/benchmark.jl:26
[12] include_from_node1(::String) at ./loading.jl:569
[13] include(::String) at ./sysimg.jl:14
[14] process_options(::Base.JLOptions) at ./client.jl:305
[15] _start() at ./client.jl:371
while loading /home/oisov/Programming/Misc/Julia-belaps/benchmark.jl, in expression starting on line 36

Answer 1

Change println(#belapsed f()) to println(#belapsed $f()). I can't fully explain it, but here is a link to the relevant part of the docs.