Here's a breakdown of the key themes in the Hacker News discussion about Harper, supported by user quotes:
Harper's Architecture: Rule-Based, Not LLM-Based
A central theme of the discussion is the fact that Harper operates on a set of explicit rules rather than relying on a large language model (LLM). This was seen by many as a key differentiator. "This seems to use a hard coded list of explicit rules, not an LLM" according to sharkjacobs. This design choice appears to have several implications, sparking both positive and negative reactions. a2128 highlights this point: "That it doesn't use LLMs is its advantage, it runs in under 10ms and can be easily embedded in software and still provide useful grammar checking even if it's not exhaustive".
Preference for Non-LLM Approach
Several users expressed a preference for Harper's rule-based approach over LLM-based grammar tools like Grammarly. pram states, "IMO not using LLMs is a big plus in my book. Grammarly has been going downhill since they've been larding it with 'AI features,' it has become remarkably inconsistent." This sentiment suggests that some users find the predictability and consistency of rule-based systems more appealing than the sometimes unpredictable (and potentially incorrect) output of LLMs.
Concerns about LLM-Based Grammar Tools
The discussion touches on perceived issues with LLM-based grammar checking, particularly inconsistency and the generation of incorrect suggestions. As boplicity puts it, "General purpose LLMs seem to get very confused about punctuation, in my experience. It's one of their big areas of obvious failing." healsdata also shares an example of Grammarly suggesting the incorrect contraction "was trulyn't". Groxx also brings up the error rates and tendency to mirror mistakes, stating "uh. yes? it's far from uncommon, and sometimes it's ludicrously wrong. Grammarly has been getting quite a lot of meme-content lately showing stuff like that."
Harper's Current Limitations and Bug Reports
Despite the potential advantages of a rule-based system, several users pointed out limitations and bugs in Harper's current implementation. demarq demonstrates this with the sentence, "Me and Jennifer went to have seen the ducks cousin," noting, "No errors detected. So this needs a lot of rule contributions to get to Grammarly level." Other users ("orliesaurus" and "crimputer") report bugs and phrases not being flagged. Specifically, crimputer says: "Good start. But still has bugs i guess. I tried with the following phrase -- 'This should can't logic be done me.' -- No errors." These comments suggest that while Harper may be a promising project, it still needs significant improvement in its rule set and error detection capabilities. alpb further demonstrates this with: "Similarly 0 grammatical errors flagged: 'My name John. What your name? What day today?'"
Comparison to Grammarly and LanguageTool
Grammarly is a frequent point of comparison, both in terms of features and performance. Some users suggest alternatives like LanguageTool. jacooper proposes: "I think if you can self host language tool, it would still be the better option". The implicit assumption is that these tools represent the standard against which Harper is being evaluated.
Desire for Broader Integration
The-Ludwig asks "Is there any reason why there is no firefox extension?", highlighting the desire for wider integration and accessibility. VTimofeenko points out that Harper "Comes with a great LSP server capable of checking grammar in code comments", demonstrating at least some existing degree of integration, but the need for browser extensions is still clearly present.
LLMs as an Alternative
While many praise Harper's choice to avoid LLMs, IceWreck offers a differing view: "Slightly controversial compared to other comments here but I haven't used Grammerly at all since LLMs came out. Even a 4B local LLM is good enough to rephrase all forms of text and fix most grammer mistakes." This comment suggests that some users find LLMs to be a viable and even preferred alternative for grammar and style checking.