transform dropargs -- whole argument list is dropped when having fewer arguments

[adamkardos]

Hello,

I bumped into this: whenever I want to use transform with dropargs and it is applied on a function
with fewer arguments than the indicated range to drop the whole argument list disappears.

MWE:

cfunction f, g, h;
symbols a,b,c;

local F = f(a) + g(a, b) + h(a, b, c);

transform,f,dropargs(2,last);
transform,g,dropargs(2,last);
transform,h,dropargs(2,last);

print +ss;
.end

this produces:

  F =
       +
         f
       +
         g(a)
       +
         h(a)
      ;

I am using: 2073865

Thanks so much!

[jodavies]

This one is similar to #267 , I’ll take a look

[jodavies]

What happens, is that (2,last) produces (2,1) which is then ordered to (1,2). Then later it checks if the second number is greater than the total number of arguments, and clamps it.

Here we should "do nothing" if either number is greater than the total of arguments.

[jodavies]

Without modifying FindRange it isn't possible to know if a number came from last or was directly supplied by the user. The manual is not specific regarding what happens in these cases, and not all operations are consistent (#267) so maybe the questions are for @vermaseren :

• what should transform f dropargs(1,2); do to f(1) ?
• what should transform f dropargs(2,last); do to f(1) ?

And the same questions apply to addargs, mulargs too.