make load command own its path memory

src/lang.zig

@@ -159,7 +159,7 @@ pub const Command = struct {
     pub const Load = struct {
         pub const base_tag = Tag.load;
         base: Command,
-        path: []const u8,
+        path: []u8,
     };
 
     pub const Quicksave = struct {
@@ -566,6 +566,7 @@ pub const Lang = struct {
                     usize => try std.fmt.parseInt(usize, arg, 10),
                     i32 => try std.fmt.parseInt(i32, arg, 10),
                     f32 => try std.fmt.parseFloat(f32, arg),
+                    []u8 => try self.allocator.dupe(u8, arg),
                     []const u8 => try self.allocator.dupe(u8, arg),
                     else => @compileError("Invalid parameter type (" ++ @typeName(cmd_field.field_type) ++ ") left on command struct " ++ @typeName(command_struct) ++ "."),
                 };

src/main.zig

@@ -57,13 +57,16 @@ pub fn doRepl(allocator: *std.mem.Allocator, args_it: var) !void {
     } else {
         // if there isn't any commands on the file, we load our default
         // 'load :0' command
-        var loadargs = langs.ArgList.init(allocator);
-        try loadargs.append(":0");
 
-        try cmds.append(langs.Command{
-            .command = .Load,
-            .args = loadargs,
-        });
+        // TODO: deliberate memleak here. we only allocate this
+        // command once, for the start of the file, so.
+        var load_cmd = try allocator.create(langs.Command.Load);
+        std.mem.copy(u8, load_cmd.path, ":0");
+        load_cmd.base.tag = langs.Command.Tag.load;
+
+        // taking address is fine, because load_cmd lives in the lifetime
+        // of the allocator.
+        try cmds.append(&load_cmd.base);
     }
 
     if (file_read_opt) |file_read| {