There's an awful lot to like about NIM. It has a few issues that would make experienced developers hesitant to adopt it. I will list them in order from most to least problematic, followed by a brief rationale for each:
1. Lack of block delimiters such as braces, or begin/end. 2. Object layout format 3. Object method calling convention 4. Missed opportunity to realize Ada's powerful type specification Programs need structure and containment. There is a reason modern code editors have all kinds of visual facilities for emphasizing them. When staring at code, it's easy to lose focus or get lost in the sea of code. Without block delimiters, you're relying purely on indentation. It also saves little vertical space over delimiters; line breaks add vertical separation instead. Python gets away with it because most of its programs are quite short. Block delimiters have been a fixture in most programming languages since the 60s when displays and punched cards were limited to 25 lines or less. If they offered no value, they would have gone the way of the dodo early on. Of all the wonderful ideas to steal from Ada, its object layout formatting is the one to leave behind, but Nim went for the wrong bag. The majority of object-oriented languages syntactically nest operations and data members inside the object declaration. Like block statements, it visually emphasizes the concept of containment or encapsulation. Ada, and now Nim, broke this well-established convention. Many would-be Ada developers are completely turned off by it, complaining it's weird and gross and offers no advantages. Unfortunately, Ada is stuck with this unfortunate design due to backward compatibility. Hopefully, it's not too late for Nim to change course. Nim's object method calling convention was also in the bag with Ada's object layout formatting. It's equally a big point of contention with many Ada developers. Requiring the method's associated object in its list of parameters is a grave oversight and belies Nim's minimalist syntax goals. Ironically, Nim improved it to conform with the more common convention. While Ada can't undo its object layout mistake, it did implement an alternate syntax for its 2012 release, implying its calling convention wasn't well received. While the issue has been largely resolved in Nim, referring to it as syntactic sugar in the documentation is a begrudging dismissal of its value. I hope I'm it's a false perception. Finally, breaking into Ada's safe and walking out with the bag containing its worst goodies while leaving behind its shimmering crown jewel warrants severe punishment, not for the heist, but for its poor appraisal. Ada's type specification is by far its best feature, which no other language has managed to achieve. The ability to specify constraints, and even static expressions, so exquisitely and precisely kept an otherwise overwhelmingly pedantic language relevant for several decades. The serves as metadata, providing the compiler with the programmer's intent and a beyond-AI level of optimization hints that would be otherwise unknown. I hope it's not too late to change direction on these issues.
