import "cffc.hff";
import "map.hff";
import "util.hff";
import "common.hff";

struct StringKeyTraits {
   fn hash(s *const u8) u32 { return fnv1a_s(FNV1A_INI, s); }
   fn eq(a *const u8, b *const u8) bool { return streq(a, b); }
}

struct Env {
   parent *Env,
   alloc *Allocator,
   decls Map<*const u8, *DeclList, StringKeyTraits>,
}

extern fn mkenv(parent *Env, alloc *Allocator) *Env {
   let env *Env = xmalloc(sizeof Env);
   *env = { parent, alloc };
   return env;
}

extern fn envput(env *Env, decl Decl, old **const Decl) *Decl {
   let l **DeclList = env.decls->get_slot(decl.name);
   let n *DeclList = anew(env.alloc, DeclList);
   if *l { // decl with this name exists
      *old = &(*l).decl;
      return #null;
   }
   n.link = *l;
   n.decl = decl;
   *l = n;
   return &n.decl;
}

extern fn envfind(env *Env, name *const u8) *Decl {
   let l **DeclList = env.decls->get(name);
   if l == #null { return #null; }
   let l = *l;
   assert(l != #null, "l?");
   return &l.decl;
}

extern fn envfree(env *Env) void {
   env.decls->clear();
   free(env);
}