Bend 2 and the Vibe-Coding Trap

Bend is often cited as a prime example of the concept of "vibe-coding," a term that highlights the tendency for developers to construct a comprehensive system based on initial impressions and assumptions. While Bend may appear impressive in its claim to streamline the process of writing "laws" and allowing AI to generate implementations and proofs, a closer examination reveals several significant issues. This article aims to shed light on the pitfalls associated with vibe-coding and how it can lead to suboptimal solutions.

The first issue with Bend lies in the substantial amount of code required for its demonstration. The developer must write over 50 lines of code to specify that a player cannot reach the flag, thereby failing to achieve victory in the game. This code snippet, while not critical to the discussion, emphasizes the extensive effort needed to achieve a straightforward outcome.

Furthermore, the LLM responsible for crafting the code is granted the power to redefine the Game subprograms in any manner it sees fit, a feature that, again, is not the focus of this article.

Another glaring problem with Bend's approach is the significant amount of code required to validate the "laws" that the developer has written. In this case, the LLM must generate 442 lines of code to prove those seemingly simple properties. At first glance, this may seem acceptable, but upon closer inspection, it becomes clear that the developer has likely overlooked an important resource: formal verification.

This field, which has proven techniques for ensuring the correctness of code, remains conspicuously absent from Bend's webpage or codebase.

To demonstrate the extent of this oversight, the author of this article recreated the same demonstration in SPARK, a language and compiler dedicated to formal verification. It is essential to note that the author approached this task without any preconceived notions about how to proceed, relying solely on their knowledge of formal verification. In contrast, Bend's developer appears to have approached the problem with a limited understanding of the field, resulting in an unnecessarily verbose and inefficient solution.

By comparing the two approaches side by side, it becomes evident that Bend's design falls victim to the vibe-coding trap. This trap entails constructing an entire system based on initial assumptions and limited knowledge, without taking the time to explore existing resources and best practices. In Bend's case, the developer failed to recognize the potential benefits of leveraging formal verification, instead opting for a verbose and time-consuming approach.

The repercussions of this design choice extend beyond Bend itself, as vibe-coding can lead to a broader problem of implementing solutions that are outdated or fundamentally flawed. When a developer employs a vibe-coding approach, they risk producing a language and compiler that may be decades behind the current state of the art. This is because the developer may lack the necessary research and insight to identify more efficient or effective methods for solving the given problem.

In conclusion, the Bend example serves as a cautionary tale about the perils of vibe-coding. While the idea of a language that allows developers to write "laws" and have AI generate implementations and proofs is enticing, it is crucial to approach such endeavors with a solid understanding of the underlying field. In the case of formal verification, this means recognizing that existing tools and techniques can significantly streamline the process, eliminating the need for extensive manual effort.

By failing to do so, Bend's developer inadvertently fell into the vibe-coding trap, resulting in a solution that is not only verbose but also potentially suboptimal.