[Macro] Extends Abstract Enum

[Théo Sabattié]

Hi everyone ! :D

I am trying to copy field of an abstract to an other.

Instead of:

@:enum abstract PrimitiveNumber(String) to String 

{

    var FLOAT = "FLOAT";

    var INT   = "INT";
}

@:enum abstract PrimitiveType(String) to String
{
    var FLOAT  = "FLOAT";
    var INT    = "INT";
    var STRING = "STRING";
    var BOOL   = "BOOL";
}

@:enum abstract Type(String) to String
{
    var FLOAT  = "FLOAT";
    var INT    = "INT";

    var STRING = "STRING";
    var BOOL   = "BOOL";
    var OBJECT = "OBJECT";
    var LIST   = "LIST";
    var MAP    = "MAP";
    var ENUM   = "ENUM";
}

I would like get write that:

@:enum abstract PrimitiveNumber(String) to String 

{

    var FLOAT = "FLOAT";

    var INT   = "INT";
}

@:build(AbstractTools.extendEnum(PrimitiveNumber))
@:enum abstract PrimitiveType(String) to String 
{
    var STRING = "STRING";
    var BOOL   = "BOOL";
}

@:build(AbstractTools.extendEnum(PrimitiveType))
@:enum abstract Type(String) to String 
{
    var OBJECT = "OBJECT";
    var LIST   = "LIST";
    var MAP    = "MAP";
    var ENUM   = "ENUM";
}

I wrote that:

#if macro
import haxe.macro.Context;
import haxe.macro.Expr;
using haxe.macro.Tools;
#end


class AbstractTools {
    public static macro function extendEnum(typePath:Expr):Array<Field> {
        var fields = Context.getBuildFields();
        var type   = Context.getType(typePath.toString());
        var lField:Field;
       
        switch (type.follow()) {
            case TAbstract(_.get() => ab, _) if (ab.meta.has(":enum")):
                var valueExprs = [];
               
                for (classField in ab.impl.get().statics.get()) {
                    if (classField.meta.has(":enum") && classField.meta.has(":impl")) {
                        var fieldName = classField.name;
                       
                        lField = {
                            name: fieldName,
                            doc: null,
                            meta: [],
                            access: [AStatic, APublic],
                            kind: FVar(macro : String, macro $typePath.$fieldName),
                            pos: Context.currentPos()
                        };
                        fields.push(lField);
                    }
                }
            default:
                throw new Error(type.toString() + " should be @:enum abstract", typePath.pos);
        }
       
        return fields;
    }
}

But build meta seems to work only with string parameter because I get this error:

PrimitiveNumber should be string on compilation but I have autocompletion.

kind: FVar(macro : String, macro $typePath.$fieldName),

Here, "String" must be type of abstract, but I don't know how to get it.

Do you have an idea to fix that? :)

Thanks

Théo Sabattié.

[Yoni Gueta]

you need to transform your  type to a complexType:

http://try-haxe.mrcdk.com/#4E792

(look at compiler output tab)

[Théo Sabattié]

Great! Thanks a lot for the fix ! 

There is a last issue :

trace(Typer.OBJECT);

trace(Typer.STRING);

trace(Typer.FLOAT);

There isn"t problem for first and second but the third break compilation with this error:

Test.hx:11: characters 10-21 : Typer has no field FLOAT

Is there a way to invoke build of PrimitiveType to get its built fields?

Thanks.

[Yoni Gueta]

your welcome :)

it seems  that your'e skipping the fields due to this condition:   "if ((classField.meta.has(":enum") && classField.meta.has(":impl")) "

the PrimitiveNumber fields exist but are stripped from their meta when built by the Typer. im  not sure why.

[Théo Sabattié]

Ok', but if I remove that condition I get an error.

We can extend PrimitiveNumber and PrimitiveType for Type like this:

@:enum abstract PrimitiveNumber(String) to String 

{

    var FLOAT = "FLOAT";

    var INT   = "INT";
}

@:build(AbstractTools.extendEnum(PrimitiveNumber))
@:enum abstract PrimitiveType(String) to String 
{
    var STRING = "STRING";
    var BOOL   = "BOOL";
}

@:build(AbstractTools.extendEnum(PrimitiveNumber))

@:build(AbstractTools.extendEnum(PrimitiveType))
@:enum abstract Type(String) to String 
{
    var OBJECT = "OBJECT";
    var LIST   = "LIST";
    var MAP    = "MAP";
    var ENUM   = "ENUM";
}

But it isn't a really good solution  I think...

Do you know an other way?