3 ms·

> If either string has a space or other invalid character, it's invalid Nope, could have a quoted string which can contain whitespace. addr-spec = l

> If either string has a space or other invalid character, it's invalid Nope, could have a quoted string which can contain whitespace. addr-spec = local-part "@" domain local-part = dot-atom / quoted-string / obs-local-part qtext = %d33 / ; Printable US-ASCII %d35-91 / ; characters not including %d93-126 / ; "\" or the quote character obs-qtext qcontent = qtext / quoted-pair quoted-string = [CFWS] DQUOTE *([FWS] qcontent) [FWS] DQUOTE [CFWS] > If the second string doesn't have a dot in it, it's invalid. Nope, domain names dont require a dot. <domain> ::= <subdomain> | " " <subdomain> ::= <label> | <subdomain> "." <label> > Split the second string by dot. If the last string of that array is not a valid TLD, it's invalid. (I realize new TLD's are popping up these days, so this step may not be strictly needed) Doesnt need to be a "valid TLD" to be a valid domain

RajT88 5y ago
Sure. Fine. Skip that part then. The larger point I was trying to make still stands.
- supermatt 5y ago
  Sorry, I added more issues as I copied the corresponding snippets from the RFC. Your suggestion is to not use a regexp, but is less valid, and likely less efficient than a regexp that checks for the presence of an @ anywhere than at the start.
  - RajT88 5y ago
    > Your suggestion is to not use a regexp, but is less valid, and likely less efficient than a regexp that checks for the presence of an @ anywhere than at the start. This is actually the whole point of what I wrote. Making the maintenance of the code low-effort, and having it be more permissive (i.e. less valid) and relying for the corner cases to be taken care of via email bounce. See: explainer on "Now you have 2 problems" https://arstechnica.com/information-technology/2014/05/what-is-meant-by-now-you-have-two-problems/ https://arstechnica.com/information-technology/2014/05/what-... If you read this whole comment thread you can see where this leads: increasingly complex regex in order to handle all the corner cases. Forget the corner cases, just make it "good enough" and relegate those corner cases to email bounce. Now - I don't have a case study to prove that this way of going about it is more valid than the strict regex validation you're suggesting. But I wanted to represent it as a middle ground between "just rely on email bounce" and "write a big long regex".
    - supermatt 5y ago
      I like the first comment on that article: Some people, when trying to explain something, think "I know, I'll use a Jamie Zawinski quote." Now they have two things to explain.

RajT88 5y ago

Sure. Fine. Skip that part then. The larger point I was trying to make still stands.

supermatt 5y ago
Sorry, I added more issues as I copied the corresponding snippets from the RFC. Your suggestion is to not use a regexp, but is less valid, and likely less efficient than a regexp that checks for the presence of an @ anywhere than at the start.
- RajT88 5y ago
  > Your suggestion is to not use a regexp, but is less valid, and likely less efficient than a regexp that checks for the presence of an @ anywhere than at the start. This is actually the whole point of what I wrote. Making the maintenance of the code low-effort, and having it be more permissive (i.e. less valid) and relying for the corner cases to be taken care of via email bounce. See: explainer on "Now you have 2 problems" https://arstechnica.com/information-technology/2014/05/what-is-meant-by-now-you-have-two-problems/ https://arstechnica.com/information-technology/2014/05/what-... If you read this whole comment thread you can see where this leads: increasingly complex regex in order to handle all the corner cases. Forget the corner cases, just make it "good enough" and relegate those corner cases to email bounce. Now - I don't have a case study to prove that this way of going about it is more valid than the strict regex validation you're suggesting. But I wanted to represent it as a middle ground between "just rely on email bounce" and "write a big long regex".
  - supermatt 5y ago
    I like the first comment on that article: Some people, when trying to explain something, think "I know, I'll use a Jamie Zawinski quote." Now they have two things to explain.