Okay, so gmhwxi's suggestion to use natLt(2) & natLt(3) seems to have
worked, but I'm having trouble understanding what natLt(2) & natLt(3)
actually is.
*Could anyone explain what natLt(2) & natLt(3) mean, please?* After
looking at the prelude the definition of natLt() doesn't seem
self-explanatory.
As for the suggestions to use separate val-declarations in a more
functional style, my reason for taking this approach is that I am trying to
replicate some C code in ATS. *I do agree that this is probably not the
cleanest solution, I figure that I can revise it later once I get my
overall project working.* But I appreciate the suggestions, so thank you.
Going off of what Dambaev said, *it makes sense to prove to the compiler
that 'i' is >= 0 && < 4, but what sort of statements might I use for this? *
I worked through chapter 12 of Intro to Programming in ATS, but I'm still
quite unsure on how to use proofs effectively. Thanks for this advice,
Dambaev.
Lastly, *I am running into an issue with indexing an array where the
compiler says that the function argument must be a left-value.* I assume
that 'nxt' is the one that needs to be a left-value, but !nxt doesn't make
a difference. Any help that can be provided is appreciated.
Apologies for the long response, I wanted to make sure I responded to as
many of you as possible, because you've all been really helpful. :)
Here's my updated function:
implement mat4_to_quat ( m ) = let
val tr = m.xx + m.yy + m.zz
in
if tr > 0.f then let
val s = $MATH.sqrt(tr + 1.f)
val w = s / 2.f
val x = ( mat4_at(m, 1, 2) - mat4_at(m, 2, 1) ) * (0.5f / s)
val y = ( mat4_at(m, 2, 0) - mat4_at(m, 0, 2) ) * (0.5f / s)
val z = ( mat4_at(m, 0, 1) - mat4_at(m, 1, 0) ) * (0.5f / s)
in
quat_new(x, y, z, w)
end else let
val nxt = @[int](1, 2, 0)
var q = @[float][4](0.f)
var i = 0
var j = 0
var k = 0
var s = 0
in
i := ((if mat4_at(m, 1, 1) > mat4_at(m, 0, 0) then 1 else i):natLt(2));
i := ((if mat4_at(m, 2, 2) > mat4_at(m, i, i) then 2 else i):natLt(3));
*j := nxt[i]; <-- first error message is on this line*
k := nxt[j];
s := $MATH.sqrt( (mat4_at(m, i, i) - (mat4_at(m, j, j), mat4_at(m, k,
k))) + 1.f );
q[i] := s * 0.5f;
s := (if (s != 0.f) then 0.5f / s else s);
q[3] := (mat4_at(m, j, k) - mat4_at(m, k, j)) * s;
q[j] := (mat4_at(m, i, j) + mat4_at(m, j, i)) * s;
q[k] := (mat4_at(m, i, k) + mat4_at(m, k, i)) * s;
quat_new(q[0], q[1], q[2], q[3])
end
end
Here's the new error message:
patscc -tcats /home/d4v3y/Goldelish-Engine/source/g_engine.dats
/home/d4v3y/Goldelish-Engine/source/g_engine.dats: 35545(line=1374,
offs=11) -- 35549(line=1374, offs=15): error(3): the function argument
needs to be a left-value.
/home/d4v3y/Goldelish-Engine/source/g_engine.dats: 35544(line=1374,
offs=10) -- 35551(line=1374, offs=17): error(3): the symbol [!] cannot be
resolved as no match is found.
/home/d4v3y/Goldelish-Engine/source/g_engine.dats: 35539(line=1374, offs=5)
-- 35551(line=1374, offs=17): error(3): assignment cannot be performed:
mismatch of bef/aft type-sizes:
bef: [S2Eapp(S2Ecst(g1int_int_t0ype); S2Eextkind(atstype_int),
S2Eintinf(0))]
aft: [S2Eerrexp()]
/home/d4v3y/Goldelish-Engine/source/g_engine.dats: 35562(line=1375,
offs=10) -- 35568(line=1375, offs=16): error(3): the symbol [[]] cannot be
resolved due to too many matches:
D2ITMcst(array_get_at_guint) of 0
D2ITMcst(array_get_at_gint) of 0
/home/d4v3y/Goldelish-Engine/source/g_engine.dats: 35557(line=1375, offs=5)
-- 35568(line=1375, offs=16): error(3): assignment cannot be performed:
mismatch of bef/aft type-sizes:
bef: [S2Eapp(S2Ecst(g1int_int_t0ype); S2Eextkind(atstype_int),
S2Eintinf(0))]
aft: [S2Eerrexp()]
On Thursday, July 16, 2020 at 8:12:39 AM UTC-4, d4v3y_5c0n3s wrote:
>
> So, I'm trying to mutate a var twice in order to replicate some C code
> that I am trying to port to ATS. But, I've been scratching my head as to
> why this would happen, so any help is appreciated. In an effort to not
> waste your time, I will be showing you the function with my issue along
> with the declarations for the relevant functions & typedefs. Please ask if
> you'd like me to provide more details that I may have missed.
>
> The function I'm having trouble in:
>
> implement mat4_to_quat ( m ) = let
> val tr = m.xx + m.yy + m.zz
> in
> if tr > 0.f then let
> val s = $MATH.sqrt(tr + 1.f)
> val w = s / 2.f
> val x = ( mat4_at(m, 1, 2) - mat4_at(m, 2, 1) ) * (0.5f / s)
> val y = ( mat4_at(m, 2, 0) - mat4_at(m, 0, 2) ) * (0.5f / s)
> val z = ( mat4_at(m, 0, 1) - mat4_at(m, 1, 0) ) * (0.5f / s)
> in
> quat_new(x, y, z, w)
> end else let
> val nxt = @[int](1, 2, 0)
> var q = @[float][4](0.f)
> var i = 0
> var j = 0
> var k = 0
> var s = 0
> in
> * i := ((if mat4_at(m, 1, 1) > mat4_at(m, 0, 0) then 1 else i):int);*
> * i := ((if mat4_at(m, 2, 2) > mat4_at(m, $showtype(i), i) then 2 else
> i):int); // <-- this line has the error*
> j := nxt[i];
> k := nxt[j];
> s := $MATH.sqrt( (mat4_at(m, i, i) - (mat4_at(m, j, j), mat4_at(m, k,
> k))) + 1.f );
> q[i] := s * 0.5f;
> s := (if (s != 0.f) then 0.5f / s else s);
> q[3] := (mat4_at(m, j, k) - mat4_at(m, k, j)) * s;
> q[j] := (mat4_at(m, i, j) + mat4_at(m, j, i)) * s;
> q[k] := (mat4_at(m, i, k) + mat4_at(m, k, i)) * s;
> quat_new(q[0], q[1], q[2], q[3])
> end
> end
>
>
> Here's the function's declaration:
>
> fun mat4_to_quat ( m: mat4 ) : quat = "sta#%"
>
>
> Here's the declaration for mat4_at:
>
> fun mat4_at {x:nat | x < 4}{y:nat | y < 4} ( m: mat4, x: int x, y: int y )
> : float = "sta#%"
>
>
> My full repo can be found here:
> https://github.com/d4v3y5c0n3s/Goldelish-Engine
> Here's the error message:
>
> patscc -tcats /home/d4v3y/Goldelish-Engine/source/g_engine.dats
> **SHOWTYPE[UP]**(/home/d4v3y/Goldelish-Engine/source/g_engine.dats:
> 35508(line=1373, offs=55) -- 35509(line=1373, offs=56)):
> S2Eapp(S2Ecst(g0int_t0ype); S2Eextkind(atstype_int)): S2RTbas(S2RTBASimp(1;
> t@ype))
> /home/d4v3y/Goldelish-Engine/source/g_engine.dats: 35508(line=1373,
> offs=55) -- 35509(line=1373, offs=56): error(3): the dynamic expression
> cannot be assigned the type [S2Eapp(S2Ecst(g1int_int_t0ype);
> S2Eextkind(atstype_int), S2EVar(6368))].
> /home/d4v3y/Goldelish-Engine/source/g_engine.dats: 35508(line=1373,
> offs=55) -- 35509(line=1373, offs=56): error(3): mismatch of static terms
> (tyleq):
> The actual term is: S2Eapp(S2Ecst(g0int_t0ype); S2Eextkind(atstype_int))
> The needed term is: S2Eapp(S2Ecst(g1int_int_t0ype);
> S2Eextkind(atstype_int), S2EVar(6368))
> /home/d4v3y/Goldelish-Engine/source/g_engine.dats: 35512(line=1373,
> offs=59) -- 35513(line=1373, offs=60): error(3): the dynamic expression
> cannot be assigned the type [S2Eapp(S2Ecst(g1int_int_t0ype);
> S2Eextkind(atstype_int), S2EVar(6369))].
> /home/d4v3y/Goldelish-Engine/source/g_engine.dats: 35512(line=1373,
> offs=59) -- 35513(line=1373, offs=60): error(3): mismatch of static terms
> (tyleq):
> The actual term is: S2Eapp(S2Ecst(g0int_t0ype); S2Eextkind(atstype_int))
> The needed term is: S2Eapp(S2Ecst(g1int_int_t0ype);
> S2Eextkind(atstype_int), S2EVar(6369))
>
> |
>
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