Auto merge of #43442 - zackmdavis:note_available_field_names_if_levenshtein_fails, r=nikomatsakis
field does not exist error: note fields if Levenshtein suggestion fails When trying to access or initialize a nonexistent field, if we can't infer what field was meant (by virtue of the purported field in the source being a small Levenshtein distance away from an actual field, suggestive of a typo), issue a note listing all the available fields. To reduce terminal clutter, we don't issue the note when we have a `find_best_match_for_name` Levenshtein suggestion: the suggestion is probably right. The third argument of the call to `find_best_match_for_name` is changed to `None`, accepting the default maximum Levenshtein distance of one-third of the identifier supplied for correction. The previous value of `Some(name.len())` was overzealous, inappropriately very Levenshtein-distant suggestions when the attempted field access could not plausibly be a mere typo. For example, if a struct has fields `mule` and `phone`, but I type `.donkey`, I'd rather the error have a note listing that the available fields are, in fact, `mule` and `phone` (which is the behavior induced by this patch) rather than the error asking "did you mean `phone`?" (which is the behavior on master). The "only find fits with at least one matching letter" comment was accurate when it was first introduced in 09d99247 (January 2015), but is a vicious lie in its present context before a call to `find_best_match_for_name` and must be destroyed (replacing every letter is within a Levenshtein distance of name.len()). The present author claims that this suffices to resolve #42599.
Showing
想要评论请 注册 或 登录