project cleanup

src/main.zig

@@ -30,13 +30,16 @@ pub fn main() !void {
     }
     const allocator = gpa.allocator();
 
-    var lexer = al.Lexer.init(@constCast("3*2+2.2"));
+    var lexer = try al.Lexer.init(allocator, @constCast("2+3+4"));
     var parser = al.Parser.init(allocator, &lexer);
     defer parser.deinit();
     const graph = try parser.buildGraph();
-    defer graph.?.deinit(&parser);
-    std.debug.print("digraph G {{\n", .{});
-    nodeName(graph.?);
-    printGraph(graph.?);
-    std.debug.print("}}\n", .{});
+    if (graph) |g| {
+        defer g.deinit(&parser);
+        std.debug.print("digraph G {{\n", .{});
+        nodeName(g);
+        printGraph(g);
+        std.debug.print("}}\n", .{});
+    }
+    
 }