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From: Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid>
Newsgroups: comp.compilers
Subject: Re: Spell checking identifiers
Date: Wed, 24 Jun 2020 03:56:56 +0800
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> [There's a vast amount of work on edit distance.  My guess is they
> use something like Levenshtein, but rather than use a constant
> distance of 1 between different letters, the distance varies depending
> on how different the letters look. -John]

This clang blog specifically mentions Levenshtein,


http://blog.llvm.org/2010/04/amazing-feats-of-clang-error-recovery.html#spell_checker

and it looks like what people do is to go through the entire symbol
table and compute it against the individual erroneous identifier.

I thought that'd be a bit on the expensive side, because C++ files
can have 100k+ (or millions?) of lines after preprocessing, so one
translation unit really can go up to million identifiers in practice.
[I don't know if that actually happens but I don't think it's safe
to assume it doesn't.]

In the 10 years since, people may have changed from standard Levenshtein
as you mention.

But then, maybe compilation speed for erroneous input isn't really
important.  rustc is slow for a short input file in both cases [which
could be the startup cost.]

--
Johann | email: invalid -> com | www.myrkraverk.com/blog/
I'm not from the Internet, I just work there. | twitter: @myrkraverk