Doing
typealias B Union{A}
makes B the same as A. Is this code meant to work today or is this
something you're proposing should work?
On Wednesday, March 23, 2016, kunal singh <[email protected]> wrote:
> Hi,
>
> I wrote a sample code which explains how inheritance can be done in Julia
> Let me explain what the code is about
> There is a Base Class : basic
> it contains two functions A and B
>
> Then there is number class which inherits from basic
> and number has its own Function C
> So number has in total three Functions A, B and C
>
> there is integer class which inherits from number
> and integer has its own Function D
> So integer has in total Four Functions A, B, C and D
>
> So what my code will be doing : I will be entering each class and printing
> all the function available in the particular class
>
> type basic
> x::AbstractString
> function basic()
> z = new()
> return z
> end
>
> function basic(p::AbstractString) # Defining Function A
> z = new(p)
> return z
> end
> end
>
> function basic(p::Int) #Defining Function B
> z = basic()
> z.x = "I am Function B from basic via outer constructor"
> return z
> end
>
> println("Entering basic")
> println("Calling Function A...")
> m = basic("I am Function A from basic via inner constructor")
> println(m.x)
>
> println("Calling Function B...")
> m = basic(0)
> println(m.x)
>
>
> typealias number Union{basic}
>
> function number(p::Float64) # Defining Function C
> z = basic()
> z.x = "I am Function C from number via number's outer constructor"
> return z
> end
>
> println("number inherits basic ")
> println("Entering number")
>
> println("Calling Function A...")
> m = number("I am Function A of basic via basic's inner constructor")
> println(m.x)
>
> println("Calling Function B...")
> m = number(10)
> println(m.x)
>
> println("Calling Function C...")
> m = number(4.5)
> println(m.x)
>
>
> typealias integer Union{number}
>
> println("integer inherits number ")
> println("Entering integer")
>
> println("Calling Function A...")
> m = number("I am Function A of basic via basic's inner constructor")
> println(m.x)
>
> println("Calling Function B...")
> m = number(10)
> println(m.x)
>
> println("integer inherits number Calling Function C...")
> m = integer(5.6)
> println(m.x)
>
> function integer(p::Float64) #Defining Function D
> z = basic()
> z.x = "I am Function D from integer via integer's outer constructor"
> return z
> end
>
> println("Calling Function D...")
> m = integer(5.6)
> println(m.x)
>
>
>
> On Tuesday, March 22, 2016 at 11:01:25 PM UTC+5:30, Stefan Karpinski wrote:
>>
>> Read through the julia-dev thread I linked to – this is addressed in
>> depth there.
>>
>> On Tue, Mar 22, 2016 at 12:55 PM, Mauro <[email protected]> wrote:
>>
>>> > By the way isn't type Basic in my code a composite type?
>>>
>>> Basic is defined both as `type` and as `abstract` which will error.
>>>
>>> > So is there any way of inheritance among composite types ?
>>>
>>> No.
>>>
>>> > Also is there any libraries which I can refer to which uses extensive
>>> > inheritance?
>>> >
>>> > In C++ we can easily inherit classes ? Why don't we have such ease in
>>> Julia ?
>>>
>>> Because Julia is designed this way. Because with the ease also comes
>>> pain.
>>>
>>> > On Tuesday, March 22, 2016 at 9:20:19 PM UTC+5:30, Stefan Karpinski
>>> wrote:
>>> >
>>> > Have a read on this oldish thread:
>>> https://groups.google.com/forum/#!topic/
>>> > julia-dev/eA4VkFAD-yQ. Still applies today.
>>> >
>>> > On Tue, Mar 22, 2016 at 11:30 AM, kunal singh <[email protected]>
>>> wrote:
>>> >
>>> >
>>> >
>>> > On Tuesday, March 22, 2016 at 8:43:50 PM UTC+5:30, Mauro wrote:
>>> >
>>> > > Hi Mauro ,
>>> > >
>>> > > Can you show me any example ?
>>> > > I am a beginner in Julia. It would of great help for me.
>>> >
>>> > In Julia the number types are defined here:
>>> > https://github.com/JuliaLang/julia/blob/
>>> > fdbcdf78bf0106e609a8d83b9e896d2d11bae594/base/boot.jl#L156
>>> >
>>> > So there are the abstract types:
>>> >
>>> > abstract Number
>>> > abstract Real <: Number
>>> > abstract AbstractFloat <: Real
>>> > abstract Integer <: Real
>>> > abstract Signed <: Integer
>>> > abstract Unsigned <: Integer
>>> >
>>> > and then there are concrete subtypes. For example a few
>>> integer
>>> > types:
>>> >
>>> > bitstype 8 Bool <: Integer
>>> > bitstype 64 Int64 <: Signed
>>> > bitstype 64 UInt64 <: Unsigned
>>> >
>>> >
>>> > > On Tuesday, March 22, 2016 at 8:01:47 PM UTC+5:30, Mauro
>>> wrote:
>>> > >
>>> > > You can only inherit from abstract types. Also, first
>>> > defining
>>> > >
>>> > > type number
>>> > > ...
>>> > > end
>>> > >
>>> > > and then
>>> > >
>>> > > abstract number
>>> > >
>>> > > is not possible. It cannot be both abstract and
>>> concrete.
>>> > (Also note
>>> > > that types are by convention Captialized).
>>> > >
>>> > > So build your hierarchy only with abstract types and
>>> make
>>> > concrete types
>>> > > of some of the abstract ones.
>>> >
>>> > Can you explain this point please ?
>>> > > On Tue, 2016-03-22 at 15:26, kunal singh <
>>> [email protected]>
>>> > wrote:
>>> > > > So basically there is a type called Basic defined as
>>> > follows
>>> > > >
>>> > > > type Basic
>>> > > > ptr::Ptr{Void}
>>> > > > function Basic()
>>> > > > z = new(C_NULL)
>>> > > > ccall((:basic_new_stack, :libsymengine), Void, (Ptr
>>> > {Basic}, ), &z)
>>> > > > finalizer(z, basic_free)
>>> > > > return z
>>> > > > end
>>> > > > end
>>> > > >
>>> > > > Now I want to create a hierarchy: integer(not
>>> Integer)<
>>> > number(not
>>> > > Number) <
>>> > > > Basic
>>> > > >
>>> > > > But in Julia, we cannot inherit from concrete type
>>> So what
>>> > should I Do??
>>> > > >
>>> > > > Here's My approach
>>> > > >
>>> > > > abstract Basic
>>> > > >
>>> > > > type number <: Basic
>>> > > > ptr::Ptr{Void}
>>> > > > function number()
>>> > > > z = new(C_NULL)
>>> > > > ccall((:basic_new_stack, :libsymengine), Void, (Ptr
>>> > {Basic}, ), &z)
>>> > > > finalizer(z, basic_free)
>>> > > > return z
>>> > > > end
>>> > > > end
>>> > > >
>>> > > > abstract number
>>> > > >
>>> > > > type integer <: number
>>> > > > ptr::Ptr{Void}
>>> > > > function integer()
>>> > > > z = new(C_NULL)
>>> > > > ccall((:basic_new_stack, :libsymengine), Void, (Ptr
>>> > {Basic}, ), &z)
>>> > > > finalizer(z, basic_free)
>>> > > > return z
>>> > > > end
>>> > > > end
>>> > > >
>>> > > >
>>> > > > Please tell me if I am wrong ?
>>> > > > Need help from
>>>
>>
>>
