Modify a Expr to generate a new Expr

New to Julia
1

Is there a way I can removing “(” and “)” in an Expr, like this:

The orignal Expr:

origin=:((10 |> x->x+2) |> x->x+3)

New target Expr:

target=:(10 |> x->x+2 |> x->x+3)

It has following this rules:

only the “( )” from two sides of |> is needed to be removed.

So, this Expr

origin2=:((10 |> (x->x+2)) |> x->x+3)

of which the target is

target2=(10 |> (x->x+2) |> x->x+3)
2

Often during printing, expressions are shown with more parentheses than technically necessary. You therefore can’t “remove” the parentheses from an expression. Two examples:

Redundant parentheses disappear after parsing:

julia> :((((x + y))))
:(x + y)

Clarifying parentheses appear when showing an expression:

julia> :(x |> y |> z)
:((x |> y) |> z)
1 Like
3

Yes, in printing, it is. But it matters more than printing. For example:

this repl can run correctly:

1 |> xx->xx+1 |> x->x+2-xx
 
3

while this one can not:

(1 |> xx->xx+1) |> x->x+2-xx

UndefVarError: xx not defined
4

this “works” in the REPL, but are you certain that it does what you think it does?

your definition is equivalent to

innerfun(x, xx) = x+2-xx
outerfun(xx) = innerfun(xx+1, xx)
outerfun(1) 

julia> :(x |> y |> z)
:((x |> y) |> z)

julia> :(x |> y->y |> z)
:(x |> (y->begin
              #= REPL[10]:1 =#
              y |> z
          end))
2 Likes
5

Oh, I see. I had been wrong understanding on this type of pip function.
Thank you for your reply.

1 Like