Hi,
I'm looking to make a flexible type which may or may not contain certain
fields, as well as possibly the addition of fields later on i.e. it's final
definition is decided at compilation. I figured meta-programming and macros
might be the way to achieve this as well as be educational for me.
Lets have a toy example:
type MyType
value1::Int
end
Is the first form of the type, but for another application I might want
type MyType
value1::Int
value2::Bool
value3::Float
end
Is it possible with a macro or some form of metaprogramming to dynamically
build up the definition, field by field - perhaps with a loop building a
code block that is then evaluated?
I started with
macro PXdefine(x...)
end
where x... could be a varargs I guess like (:Int, :Bool, :Float),
then a loop build those lines along the lines of
for i in 1:length(x)
:(value$i::$x[i])
end
Then the result might be able to go in between the lines type 'MyType' and
'end'
But really I'm not 100% sure how to go about building up a chunk of code
like this to form a more complex whole. The example I've seen in the doc's
on code generation have evaluations inside a loop to define a function for
many operators, but I've not seen many examples that build up expressions
from smaller parts and then evaluate them.
Thanks,
Ben.
