"Delayed" problem in mfunction/mmacro definition

["Siver Andrey" <siver@sirius.ihep.su>, Sun, 14 Nov 2004 13:07:51 +0300]:
> (%i3) F3(x)::='(x);
> (%o3)      F3(x) ::= 'x
> (%i4) F3(y);
> (%o4)            x
> (should be 'y' instead)

,----
| (%i1) F5(x) ::= buildq([x], 'x);
| 
| (%o1)                      F5(x) ::= BUILDQ([x], 'x)
| (%i2) F5(y);
| 
| (%o2)                                  y
`----

> This is important question for definition of Mathematica ":="
> (SetDelayed) function for MAXIMA (I thought that 'SetDelayed' could
> be interpreted as (MDEFINE) (or (MDEFMACRO)) but with second
> argument (MQUOTE)ed and with first argument 'a' --> (MEVAL a) at the
> evaluation time BUT found it's not a case).

If you only want to do something like

    f[x_] := Sin[x]

so that

    f[2] --> Sin[2]

    f[1+1] --> Sin[2]

, you can simply use Maxima's ":=" which already does the right thing;
if you want the right hand side to be evaluated (as with Set) you have
to explicitly ask for that with, e.g., ''.

HTH,

Albert.