You could also use a macro:
module MetaFoo
export Foo, ops, @foo_op
type Foo{T<:Number}
x::Vector{T}
end
const ops = [+, -, *, /]
const syms = [symbol(op) for op in ops]
for sym in syms
dot_sym = symbol(".$sym")
docstr = "`$sym` also works for `Foo` types!"
@eval begin
@doc $docstr ->
function Base.$sym(a::Foo, b::Foo)
Foo($dot_sym(a.x, b.x))
end
end
end
macro foo_op(op)
dot_op = symbol(".$op")
docstr = "`$op` also works for `Foo` types!"
quote
function Base.$op(a::Foo, b::Foo)
Foo($dot_op(a.x, b.x))
end
@doc $docstr Base.$op
Base.$op
end
end
end
Use:
help?> +
search: + .+
+(x, y...)
Addition operator. x+y+z+... calls this function with all arguments, i.e.
+(x, y, z, ...).
julia> include("MetaFoo.jl")
MetaFoo
julia> using MetaFoo
help?> +
search: + .+
+(x, y...)
Addition operator. x+y+z+... calls this function with all arguments, i.e.
+(x, y, z, ...).
+ also works for Foo types!
help?> ^
search: ^ .^
^(x, y)
Exponentiation operator.
^(s, n)
Repeat n times the string s. The repeat function is an alias to this
operator.
julia> "Test "^3
"Test Test Test "
julia> @foo_op ^
^ (generic function with 46 methods)
help?> ^
search: ^ .^
^(x, y)
Exponentiation operator.
^(s, n)
Repeat n times the string s. The repeat function is an alias to this
operator.
julia> "Test "^3
"Test Test Test "
^ also works for Foo types!
julia>
El martes, 15 de diciembre de 2015, 10:28:53 (UTC-6), [email protected]
escribió:
>
> Hello,
>
> I have a type M and I would like to redefine all the operations *, +, -, /
> etc. over it. Since it would be everytime the same operations and since I
> want my code to be concise I thought about using a macro to define them,
> such as:
>
> type M
> a
> b
> end
>
> macro operator_obs(name)
> return quote
> function $name(m1::M, m2::M)
> return M($name(m1.a, m2.a), $name(m1.b, m2.b))
> end
> end
> end
>
> @operator_obs(+)
>
> m1 = M(2.0,3.0)
> m2 = M(4.0,5.0)
>
> +(m1, m2)
>
> But this doesn't seem to work. What did I do wrong?
>
> Many thanks,
>
