It's easier if you split up Eq
#include "share/atspre_define.hats"
#include "share/atspre_staload.hats"
datatype Expr(a:t@ype) =
| I(int) of int
| B(bool) of bool
| Add(int) of (Expr int, Expr int)
| Mul(int) of (Expr int, Expr int)
| Eqi(bool) of (Expr int, Expr int)
| Eqb(bool) of (Expr bool, Expr bool)
extern fun{a:t@ype} equals(t1:a, t2:a): bool
implement equals<int>(t1,t2) = g0int_eq(t1,t2)
implement equals<bool>(t1,t2) = eq_bool0_bool0(t1,t2)
extern fun {a:t@ype} eval(x:Expr a): a
implement eval<int>(x) =
case- x of
| I i => i
| Add (t1, t2) => eval(t1) + eval(t2)
| Mul (t1, t2) => eval(t1) * eval(t2)
implement eval<bool>(x) =
case- x of
| B b => b
| Eqi (t1, t2) => equals<int>(eval(t1), eval(t2))
| Eqb (t1, t2) => equals<bool>(eval(t1), eval(t2))
implement main0() = let
val term1 = Eqi(I(5), Add(I(1), I(4)))
val term2 = Mul(I(2), I(4))
val term3 = Eqb(B(true), B(false))
val res1 = eval(term1)
val res2 = eval(term2)
val res3 = eval(term3)
in
println!("res1=", res1, " res2=", res2, " and res3=", res3)
end
On Monday, October 15, 2018 at 8:51:15 PM UTC-5, Chris Double wrote:
>
> I have some GADT code that fails at the C compilation stage. It's a
> variant of:
>
> https://gist.github.com/doublec/a3cc8f3431cabe9a319c8e7ba27e7890
>
> But the Eq constructor of Expr uses the type index instead of being
> 'int' so equality can be done against booleans and ints. The full code
> is:
>
> ----------------8<---------------
> #include "share/atspre_define.hats"
> #include "share/atspre_staload.hats"
>
> datatype Expr(a:t@ype) =
> | I(int) of int
> | B(bool) of bool
> | Add(int) of (Expr int, Expr int)
> | Mul(int) of (Expr int, Expr int)
> | Eq(bool) of (Expr a, Expr a)
>
> extern fun{a:t@ype} equals(t1:a, t2:a): bool
> implement equals<int>(t1,t2) = g0int_eq(t1,t2)
> implement equals<bool>(t1,t2) = eq_bool0_bool0(t1,t2)
>
> fun{a:t@ype} eval(x:Expr a): a =
> case+ x of
> | I i => i
> | B b => b
> | Add (t1, t2) => eval(t1) + eval(t2)
> | Mul (t1, t2) => eval(t1) * eval(t2)
> | Eq (t1, t2) => equals(t1, t2)
>
> implement main0() = let
> val term1 = Eq(I(5), Add(I(1), I(4)))
> val term2 = Mul(I(2), I(4))
> val res1 = eval(term1)
> val res2 = eval(term2)
> in
> println!("res1=", res1, " and res2=", res2)
> end
> ----------------8<---------------
>
> This fails to compile at the C stage with:
>
> In file included from arith3_dats.c:15:0:
> arith3_dats.c: In function ‘eval_2__2__1’:
> arith3_dats.c:1098:24: error: ‘PMVtmpltcstmat’ undeclared (first use
> in this function)
> ATSINSmove(tmpret2__1,
> PMVtmpltcstmat[0](equals<S2EVar(5554)>)(tmp9__1, tmp10__1)) ;
> ^
> ATS2-Postiats-0.3.11//ccomp/runtime/pats_ccomp_instrset.h:276:37:
> note: in definition of macro ‘ATSINSmove’
> #define ATSINSmove(tmp, val) (tmp = val)
> ....
>
> Any thoughts on what I'm doing wrong?
>
> --
> https://bluishcoder.co.nz
>
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