parse error on for loop in macro in function call

[yha]

These trigger a syntax error, which seems wrong:

foo(@bar for i in x; end)  # => ERROR: syntax: unexpected "end"

foo(@bar for i in x
    i
end)  # => ERROR: syntax: missing comma or ) in argument list

These parse fine:

foo(@bar while i in x; end)
foo(@bar while i in x; 
    i
end)
foo(@bar begin for i in x; end end)
foo(begin @bar for i in x; end end)

julia> versioninfo()
Julia Version 1.1.1
Commit 55e36cc308 (2019-05-16 04:10 UTC)
Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: Intel(R) Core(TM) i9-7940X CPU @ 3.10GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-6.0.1 (ORCJIT, skylake)
Environment:
  JULIA_NUM_THREADS = 14

[JeffBezanson]

See #18650. We decided to resolve this ambiguity in favor of generators, since for loops do not return values. Granted, the macro could do something to make the for loop return a value. Did this arise from a real world case like that?

[yha]

Yes, I was trying to do something like

using Interact
pad(1em, @manipulate for filename=dropdown(readdir(dir))
    ...
end)

So if I understand correctly, it tries to parse this as a generator expression as if it said pad(1em, (@manipulate) for ... end)?

[JeffBezanson]

Yes.