Regex: remove parens to turn a julia function call into a macro call

julia-regex-replace-function-call-with-macro.jl

julia> m = "call( a( x()-1 ), 2+2 )"
>> "call( a( x()-1 ), 2+2 )"

julia> replace(m, r"a(\(((?>[^()]|(?1))*)\))" => s"@b \2")
>> "call( @b  x()-1 , 2+2 )"

julia> # You can see the two capture groups here: the first around the parens (used for recursion), and the second inside the parens (for substitution).
julia> match(r"a(\(((?>[^()]|(?1))*)\))", m)
>> RegexMatch("a( x()-1 )", 1="( x()-1 )", 2=" x()-1 ")