>Alejandro,
>sorry it took me so long to get back to you.
>Don´t want to put too much time into it, but we´re talking about three things here: macro substitution, Evaluate() and name expressions.
>
>Maybe I was wrong to have compared macros and Eval() and I should have rather said macros and name expressions.
>
>While you can use two or even three interchangeably in some situations, there are some very distinct usages.
>

>*this is more than twelve years old
>*it creates sort of 'pointers' into arrays
>*named after the open tables
>*so you can change the structure of the table
>*and don´t need to change data binding
>SET SAFETY OFF
>CREATE TABLE test (c12 C(12) NOT NULL, n31 N(3,1) NOT NULL )
>SET SAFETY ON
>PUBLIC aTbl(1,2)
>aTbl(1,1)=ALIAS()
>aTbl(1,2)="t" &&table signature
>FOR m.nCntr1=1 TO 1 &&actually iterate over open tables
>* use name expr to create public array
>*  dimensioned to the fcount() of the table
> PUBLIC ("r"+LOWER(ALIAS())+"("+LTRIM(STR(FCOUNT(),3))+")")
>* use name expr to scatter to this array

Thanks for the reply.
> SCATTER MEMO TO ("r"+ALIAS())
> FOR m.nCntr2=1 to FCOUNT()
>* create variable names from table signature+field name
>* resulting in: tC12 and tN31
>  m.cTmp=aTbl(m.nCntr1,2)+FIELD(m.nCntr2)
>  PUBLIC (m.cTmp)
>* assign the 'pointer' value to the var ONLY POSSIBLE WITH MACRO
>* resulting in: tC12=1, tN31=2
>  &cTmp=m.nCntr2
>* for demo purposes only:
>  ?(m.cTmp)
>* a bit funny
>  ?(EVALUATE(m.cTmp))
>* eVALuate() to get the VALUE!!!
>  ?EVALUATE(m.cTmp)
> ENDFOR
>ENDFOR
>*check in debugger before clearing
>*CLEAR ALL
>

>
>There´s actually much more fun to it...
>Cheers
>G

Thanks Guenter,

I think the main difference between the three things may be *when* VFP resolves them.

My guess is that a command line that contains a macro is completely reevaluated each time it's found at runtime, but a line that contains an EVAL() or a name expression (if that is what an expression between parentheses is called) is mostly pre-compiled with only that element left for runtime evaluaton. That would explain why we are told that macros are bad for performance and also mean that macros don't affect performace much if used sparingly.

Alex