shithub: mc

Info  •  Files  •  Log  •  Branches

Infer types for unions.

--- a/parse/gram.y

+++ b/parse/gram.y

@@ -413,9 +413,9 @@

 unioncons

         : Ttick Tident addexpr

-            {$$ = mkexpr($1->line, Ocons, $2, $3, NULL);}

+            {$$ = mkexpr($1->line, Ocons, mkname($2->line, $2->str), $3, NULL);}

         | Ttick Tident

-            {$$ = mkexpr($1->line, Ocons, $2, NULL);}

+            {$$ = mkexpr($1->line, Ocons, mkname($2->line, $2->str), NULL);}

         | addexpr

         ;

--- a/parse/infer.c

+++ b/parse/infer.c

@@ -371,6 +371,7 @@

 static void inferexpr(Node *n, Type *ret, int *sawret)

 {

     Node **args;

+    Ucon *uc;

     int nargs;

     Node *s;

     Type *t;

@@ -511,7 +512,16 @@

             }

             break;

         case Ocons:

-            die("Union constructors not yet supported\n");

+            uc = getucon(curstab(), args[0]);

+            if (!uc)

+                fatal(n->line, "No union constructor %s", namestr(n));

+            if (!uc->etype && n->expr.nargs > 1)

+                fatal(n->line, "nullary union constructor %s passed arg ", ctxstr(args[0]));

+            else if (uc->etype && n->expr.nargs != 2)

+                fatal(n->line, "union constructor %s needs arg ", ctxstr(args[0]));

+            else

+                unify(n, uc->etype, type(args[1]));

+            settype(n, uc->utype);

             break;

         case Olit:      /* <lit>:@a::tyclass -> @a */

             switch (args[0]->lit.littype) {