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sylware



Joined: 23 Oct 2020
Posts: 81
Location: Marseille/France
sylware
I am structuring in a tree-like hierarchy my app using fasmg namespaces (in C89, I use the preprocessor).
Since a raw namespace (no symbol class instance attached to it) has not its direct children "browsable" by siblings or its children of any depth while upward walking the namespace hierarchy... I was wondering if there is a "better" way to "push" into a specific namespace external dependencies, like external labels for instance.
Post 09 Sep 2021, 18:05
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bitRAKE



Joined: 21 Jul 2003
Posts: 3307
Location: vpcmipstrm
bitRAKE
This confused me for a great while (maybe still). I would write little tests to wrap my head around it. Namespace, in many ways, is not like namespace of other languages.
Code:
banana equ

namespace TacoLand

        ; change parent context
        banana. reequ 'banana0'

        ; existing local context overrides setting parent
        ; the symbol is shadowed
        define banana
        banana. reequ 'taco0'

        ; can't reach parent context once local context exists
        ; or if parent context doesn't exist (obviously)
        grape equ banana.
        define banana 'taco1'
end namespace

display 10,banana
display 10,9,TacoLand.grape
display 10,9,TacoLand.banana

; non-dot symbols search in the present namespace
PizzaLand:
        define .banana 'pizza0'
        banana reequ 'banana1'
        ; can access both non-/dot banana
        .grape equ .banana
        define .banana 'pizza1'

display 10,banana
display 10,9,PizzaLand.grape
display 10,9,PizzaLand.banana

namespace NoodleLand

        ; get parent value
broth:
        .grape equ banana. ; save real banana!

        ; change parent context
        banana. reequ 'banana2'

        define banana
        banana. reequ 'noodle0'

        grape equ broth.grape
        define banana 'noodle1'
end namespace

display 10,banana
display 10,9,NoodleLand.grape
display 10,9,NoodleLand.banana    
Namespace provides almost complete isolation. Once a symbol is defined in a namespace the parent is unreachable (so, if you need it, assign to local symbol before). The following dot isn't needed above (just there to indicate 'trying to reach parent'). If forward references are allowed then the parent also is not reachable because the symbol is defined everywhere in the namespace.

Presently, my use of namespace is to assign local symbols as needed - collapsing the hierarchy. I haven't tried maintaining a symbolic tree, yet.

I did run some tests also to transport symbols from one namespace to another using calminstruction's transform. With no success unfortunately. Is resolving the second parameter to transform possible - must it always be a literal value and not a value defined by a parameter/symbol?

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Post 10 Sep 2021, 15:33
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bitRAKE



Joined: 21 Jul 2003
Posts: 3307
Location: vpcmipstrm
bitRAKE
Here is another perspective:
Code:
; GreatParent
name equ 'Adam'

GrandParent: ; colon names create an anchor point in the hierarchy
namespace GrandParent
        father equ name
        define name
        name reequ 'George'

        Parent:
        namespace Parent
                father equ name
                define name
                name reequ 'Michael'

                child:
                        ; must use more complex paths at depth
                        ; or unique names (linearize/flatten)
                        .great equ GrandParent.father
                        .grand equ father ; or GrandParent.name or Parent.father or GrandParent.Parent.father
                        .father equ name ; or Parent.name
                        .name equ 'Bobby'

                        display 10,.great,'->',.grand,'->',.father,'->',.name
        end namespace
end namespace    
Post 10 Sep 2021, 16:17
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sylware



Joined: 23 Oct 2020
Posts: 81
Location: Marseille/France
sylware
Actually, until a symbol of expression class is attached to a namespace, it is not possible to "browse" it depth upward from its children, and sidewise from its siblings (of the same symbol class).
symbols of [labeled] instruction class seems to allow those though.

Hope I am not too wrong there Smile

I ended explicitely "importing" the symbols of expression class in a child namespace from the namespaces of the parent/siblings.

For "global" namespaces, I do add a symbol of expression class explicitely:
Code:
myglobalnamespace = 'visible'    


for instance:
Code:
libc = 'visible'
linux = 'visible'
    


It seems to enforce strong isolation of symbols of expression class in their namespaces: more typing, but provides an explicit inventory of what is 'imported' instead of to have to read the whole code.
Code:
namespace parent

namespace sibling
    ...
end namespace ; sibling

label child.parent.symexpcls0 at parent.symexpcls0
label child.sibling.symexpcls1 at sibling.symexpcls1

namespace child
    ...
end namespace ; parent
end namespace ; child
    
Post 10 Sep 2021, 16:58
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Melissa



Joined: 12 Apr 2012
Posts: 125
Melissa
namespaces are only needed if you work in teams, not to collide with others symbols or when you make library for same reasons
Post 18 Sep 2021, 11:57
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bitRAKE



Joined: 21 Jul 2003
Posts: 3307
Location: vpcmipstrm
bitRAKE
The new features of fasmg make stuff like ...
Code:
include 'ns04.fasmg',namespace Oh_Wow
end namespace    
... possible. Where a library can be wrapped to isolate it.
(If it wasn't written initially with that intention.)
Post 18 Sep 2021, 15:39
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Melissa



Joined: 12 Apr 2012
Posts: 125
Melissa
Beautifull I bet future on fasmg.
Post 18 Sep 2021, 21:11
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