You can actually do this if you declare Joker to be immutable (at least in 0.4, I'm not sure if that change happened before the 0.3 release or not)
On Fri, Nov 28, 2014 at 5:15 AM, <[email protected]> wrote: > Ok, so the parameter can only be an integer or a type, am I right ? Is it > specified in the manual ? > > Thanks, > Sébastien > Le vendredi 28 novembre 2014 01:50:37 UTC+1, [email protected] a écrit : > >> The parameter to MyType{} needs to be a type, but Joker() is an >> instance. Just use MyType{Joker}(4) >> >> Cheers >> Lex >> >> On Friday, November 28, 2014 9:50:08 AM UTC+10, [email protected] >> wrote: >>> >>> Hello, >>> >>> Say I have a parametric type: >>> >>> type MyType{T} >>> var1 >>> end >>> >>> >>> >>> In the most of the case T is a simple integer, and there is no problem >>> with that. However, sometimes T is an instance of an singleton type, like: >>> >>> >>> type Joker end >>> >>> >>> Thus I would like to instantiate >>> >>> MyType{Joker()}(4) >>> >>> but I have the following error message: >>> >>> ERROR: type: apply_type: in MyType, expected Type{T<:Top}, got Joker >>> >>> >>> >>> Reading this message, I understand that the parameters of the types have >>> to be define "at the top"... This seems true while >>> MyType{MyType{4}(3)}(2) >>> throw a similar error message. >>> >>> In the documentation : http://julia.readthedocs.org/ >>> en/latest/manual/types/#man-parametric-types there is no mention of >>> such a restriction (or I didn't find it!). >>> >>> How can I make `MyType{Joker()}(4)` work the way I want ? >>> >>> Regards, >>> Sébastien >>> >>
