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Unify generics with names.

--- a/parse/htab.c

+++ b/parse/htab.c

@@ -195,7 +195,7 @@

 int streq(void *a, void *b)

 {

-    return !strcmp(a, b);

+    return a == b || !strcmp(a, b);

 }

 ulong ptrhash(void *key)

--- a/parse/infer.c

+++ b/parse/infer.c

@@ -99,6 +99,14 @@

     return s;

 }

+

+static int nameeq(Node *a, Node *b)

+{

+    if (a == b)

+        return 1;

+    return streq(a->name.ns, b->name.ns) && streq(a->name.name, b->name.name);

+}

+

 /* Set a scope's enclosing scope up correctly.

  * We don't do this in the parser for some reason. */

 static void setsuper(Stab *st, Stab *super)

@@ -530,6 +538,11 @@

     return 2;

 }

+static int hasparam(Type *t)

+{

+    return t->type == Tygeneric || t->type == Tyname;

+}

+

 /* Unifies two types, or errors if the types are not unifiable. */

 static Type *unify(Inferstate *st, Node *ctx, Type *a, Type *b)

 {

@@ -574,11 +587,22 @@

      * Otherwise, match up subtypes. */

     if ((a->type == b->type || idxhacked(a, b)) && tyrank(a) != 0) {

         if (a->nsub != b->nsub)

-            fatal(ctx->line, "%s has wrong subtype count for %s (got %d, expected %d) near %s\n",

+            fatal(ctx->line, "%s has wrong subtype count for %s (got %d, expected %d) near %s",

                   tystr(a), tystr(b), a->nsub, b->nsub, ctxstr(st, ctx));

         for (i = 0; i < b->nsub; i++)

             unify(st, ctx, a->sub[i], b->sub[i]);

         r = b;

+    } else if (hasparam(a) && hasparam(b)) {

+        /* Only Tygeneric and Tyname should be able to unify. And they

+         * should have the same names for this to be true. */

+        if (!nameeq(a->name, b->name))

+            fatal(ctx->line, "%s incompatible with %s near %s",

+                  tystr(a), tystr(b), ctxstr(st, ctx));

+        if (a->nparam != b->nparam)

+            fatal(ctx->line, "%s has wrong parameter list for %s near %s",

+                  tystr(a), tystr(b), ctxstr(st, ctx));

+        for (i = 0; i < a->nparam; i++)

+            unify(st, ctx, a->param[i], b->param[i]);

     } else if (a->type != Tyvar) {

         fatal(ctx->line, "%s incompatible with %s near %s",

               tystr(a), tystr(b), ctxstr(st, ctx));