Fixing addressing

- Fix double resolve bug in address handler
- Fix multiple major issues with next_closing and prev_opening functions.
- add `=` ed command.
- Other minor fixes.

src/internal/address/resolve.cc

@@ -6,9 +6,7 @@ uint64_t Address::resolve(BEd &ctx) {
   uint64_t result = std::visit(
     [&](auto const &addr) -> uint64_t {
       uint64_t line = 0;
-
       using T = std::decay_t<decltype(addr)>;
-
       if constexpr (std::is_same_v<T, std::monostate>) {
         throw address_error("empty address");
       } else if constexpr (std::is_same_v<T, None>) {
@@ -21,27 +19,32 @@ uint64_t Address::resolve(BEd &ctx) {
         line = addr.i;
       } else if constexpr (std::is_same_v<T, Block>) {
         if (addr.dir == Direction::Forward) {
-          if (ctx.active->parser)
-            line = ctx.active->parser->next_closing(ctx.active->line);
-          else
+          if (ctx.active->parser) {
+            if (ctx.active->line == 0)
+              ctx.active->line = 1;
+            line = ctx.active->parser->next_closing(ctx.active->line - 1) + 1;
+            if (line > ctx.active->vase.lines())
+              line = ctx.active->vase.lines();
+          } else {
             line = ctx.active->line + 10;
+          }
         } else {
-          if (ctx.active->parser)
-            line = ctx.active->parser->prev_opening(ctx.active->line);
-          else
+          if (ctx.active->parser) {
+            if (ctx.active->line == 0)
+              ctx.active->line = 1;
+            line = ctx.active->parser->prev_opening(ctx.active->line - 1) + 1;
+          } else {
             line = ctx.active->line - 10;
+          }
         }
       } else {
         throw ed_error("Unhandled address given.");
       }
-
       if (offset < 0 && line < (uint64_t)-offset)
         throw address_error("Can't have negative addresses");
       line += offset;
-
       if (line > ctx.active->vase.lines())
         throw address_error("Line number too high.");
-
       return line;
     },
     base