Slices

[cryptojedi]

This is a feature request to support function arguments that are "slices", i.e., arrays of variable length that is known at compile time for all contexts from which a function is called, but possibly different from different contexts. So, we would like to do something like

fn foo(reg ptr u8[reg u64 n]) {
...
}

fn bar(){
  stack u8[128] a;
  stack u8[256] b;
  foo(a);
  foo(b);
}

Syntax to be discussed. This will avoid code duplication both source level and in binaries produced from jasmin code.

[cassiersg]

Summary of discussion in Bristol:

This expands on the subarray_unknown_index.

Add integer parameters to functions that can be used as array sizes.

Would like to have:

• array length to be expressions of the parameters
• function arguments whose value is equal to a parameter. Does it mean that we have integer variables in Jasmin ?

cc @eponier @mbbarbosa @bgregoir @cryptojedi @Rixxc