Learning the wolfram Language, in section 32
"The Wolfram Language" // Characters[#]& /. Alternatives @@Characters["aeiou"] -> Nothing
Returns
{T,h,e, ,W,o,l,f,r,a,m, ,L,a,n,g,u,a,g,e}
I expected it to return
{T,h, ,W,l,f,r,m, ,L,n,g,g}
Changing it to
Characters["The Wolfram Language"] /. Alternatives @@Characters["aeiou"] -> Nothing
Returns the expected result, why?
Characters[#] & /. Alternatives @@ Characters["aeiou"] -> Nothing is processed together. You can see this by quadruple-clicking on Characters[#] -- the extended highlighting shows the operator associations and order of processing.
Processing the operations together is equivalent to constructing f, as here:
f = Characters[#] & /. Alternatives @@ Characters["aeiou"] -> Nothing;
"The Wolfram Language" // f
{T,h,e, ,W,o,l,f,r,a,m, ,L,a,n,g,u,a,g,e}
As well as the method you show, the operator binding can be fixed like this:
ReplaceAll["The Wolfram Language" // Characters[#] &,
Alternatives @@ Characters["aeiou"] -> Nothing]
{T,h, ,W,l,f,r,m, ,L,n,g,g}
("The Wolfram Language"//Characters[#]&)/.Alternatives@@Characters["aeiou"]->Nothing Gotcha, that's helpful
– Connor McCormick
Aug 25 '20 at 20:30
// not as piping syntax (as I'm used to from shell scripts) but rather as a convenient lambda creator. It takes everything prior to the // and treats it as arguments and everything after // and treats it as a function
– Connor McCormick
Aug 25 '20 at 20:34
//) notation. In this case, everything after//is grouped together. You can see this by repeatedly clickingCharactersand see how the selection expands. You'd need to write("The Wolfram Language" // Characters[#]&) /. ...to make this work. – Sjoerd Smit Aug 25 '20 at 20:23