HBAL Typechecker

Examples:

test_arith.hbal	test_call.hbal	test_jumps.hbal	test_list_paper.hbal
test_move.hbal	test_move_macro.hbal	test_parser.hbal	test_trees.hbal

(* parser test file 
 * doesn't typechecks of course !
 *)

sign
label3 : { r2:int+ }
label1 : { r2:int+, r23:[int+*int+]+, r2:<> }
(* types can omit init flags in which case they default to false
 * inside contexts, the toplevel flag is forced to true 
 * so these 2 statements are equivalent :
 * label2 : { r2:int+, r23:[int+*int+]+, r2:<> }
 * label2 : { r2:int,  r23:[int+*int+],  r2:<> }
 *)
label2 : { r2:int, r23:[int+*int+], r2:<> }
<>

load  r2 <- r5[12];
store r767[42] <- r0;
arithi r2 <- r2 + 23;
arithi r2 <- r2 - 23;
arithi r2 <- r2 * 23;
arithi r2 <- r2 / 23;
arith  r5 <- r2 + r8;
arith  r5 <- r2 - r8;
arith  r5 <- r2 * r8;
arith  r5 <- r2 / r8;
arith  r5 <- sp / r8;

label1:
label2:

bnz r4 label;
bez r2 label;
jmp label;
call this_label;
ret label;

label3:

use r23 code;
use r23 int+;
use r23 [int+]+;
use r23 int+*int+;
use r23 L(int+);
use r23 T(int+);
use r23 <>;

discard r56;
(* reuse not allowed anymore *)
(* reuse r5[12] as [int+]+; *)
salloc int+;
(* new syntax for sfree *)
sfree 4;
(* the old one is still supported *)
sfree int+;
foldnil  int+, r3[5];
foldcons int+, r3[5];
foldleaf int+, r3[5];
foldnode int+, r3[5];
caselist int+, r3[5], label;
casetree int+, r3[5], label;
move r6[3] <- r2[8], [int+ * int+]+;
<>