Hi, after migrating the string functions in the lib of the linux kernel to ats I'm now starting to to improve the code in an ats sense. A first step was to change from ptr0_get/set to ptr1 (sure, still unsafe stuff - but better type checked regarding implicit type conversions).
The code at the end demonstrates a little problem. ptr1_succ<char>(pp) doesn't have the property l:agz even pp has it. Second, looking on the template parameter of ptr1_succ I get vt0p which stands for viewt@ype. I cannot actually get this in sync with documentation, because a viewt@ype should be something like vtypedef VT(T:t@ype,l:addr) = ( T@l | ptr(l) ). So I think the template parameter should be of t0p = t@ype. Otherwise I have wrong expectations in how to use these functions - and I don't really understand why my code compiles. Finally an last minute insight regarding the usage of ptr1_pred: l:addr | l > (null + sizeof(a)) .. works - without the null not. I know, in this case I should not be surprised. But l,r:agz | r == (l + sizeof(a)) -- doesn't imply r >= l. Here is the code - c-style strlen - very often called by the kernel and the performance seems to be good. The ptr0 version works (and also my pointer type modification pgz): #define ATS_DYNLOADFLAG 0 #include "share/atspre_define.hats" #include "share/atspre_staload.hats" staload "prelude/SATS/unsafe.sats" fn strlen{l:agz}(p:ptr(l)) : [r:nat] size_t(r) = let fun loop{ll:agz| ll >= l}(pp:ptr(ll)) : [r:agz| r >= ll] ptr(r) = case+ ptr1_get<char>(pp) = '\0' of | true => pp | false => loop(ptr1_succ<char>(pp)) in g1ofg0(cast{size_t}(loop(p) - p)) end implement main0 () = let var s = @[char][4]('A','B','C','\0') val x = strlen(addr@(s)) in println!(x) end -- You received this message because you are subscribed to the Google Groups "ats-lang-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to ats-lang-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/ats-lang-users/9e71a4f6-6be7-44ed-8e61-c7b44d260b34o%40googlegroups.com.