sihui_io
rest is [“a”] and last_gift is “b”.
rest |> Enum.join(", “) returns “a”, which is a string.
“a” |> “#{}, and #{last_gift}” returns “a, and b”.
But when I pipe them together, I get ArgumentError.
rest |> Enum.join(”, ") |> “#{}, and #{last_gift}”
** (ArgumentError) argument error
What do I miss? 
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kokolegorille
You cannot pipe a variable into a string.
But You can
My guess is a string is not a function, and does accept only “” to be piped, but You can interpolate without pipe with “#{x}, and #{last}”.
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cantiero
This version looks ok IMO:
voltone
Right, so
"234#{five}"is actually<<"234", five::binary>>, which is invokingKernel.SpecialForms.<<>>. Piping something into that prepends the value at the front of that binary, if it is a legal parameter to<<>>.So in the end
"1" |> "234#{five}"expands to<<"1", "234", five::binary>>which happens to be legal. I don’t think it’s intentional.sihui_io
It turns out
a |> "#{}"doesn’t mean we are actually interpolating a into the position of#{}Last Post!
adworse
Looks totally OK, it’s relatively new though; there was no such syntax three years ago