7 ms·

f :: String -> () f g' = case (eval g' :: Maybe (String -> ())) of Just g -> g g' Nothing -> () loop :: () loop = f (quote f)

by Kutta 9y ago

mietek 9y ago
Your sketch of a proof does not appear substantially different from the proof given in section 3.1 of the linked paper. Section 3.2 explains that this result does not apply to strongly normalising languages. See also the slides titled “So what about, e.g. Fω instead of ℕ ⇒ ℕ?” in Gergo Erdi’s talk on the subject of the linked paper: https://gergo.erdi.hu/talks/2015-11-fomega/FOmegaUnquote.pdf https://gergo.erdi.hu/talks/2015-11-fomega/FOmegaUnquote.pdf Note that your sketch is one particular variation of a folklore argument, best recalled by Conor McBride in 2003: https://mail.haskell.org/pipermail/haskell-cafe/2003-May/004343.html https://mail.haskell.org/pipermail/haskell-cafe/2003-May/004... Here’s what Conor McBride has to say on the subject in 2015: https://www.reddit.com/r/haskell/comments/38wels/conor_mcbride_hasochistic_containers/cs11ppm/?context=3 https://www.reddit.com/r/haskell/comments/38wels/conor_mcbri... If you are interested in discussing this further, please feel free to contact me privately.
- Kutta 9y ago
  I am familiar with all of your listed sources (even attended one incarnation of the Érdi Gergő talk). Section 3.2 of the paper absolutely does not say that the result does not hold. The main point of the construction is that typed quoted representations can preserve totality by disallowing diagonal application. Interpreting untyped quoted representations is impossible all the same, which is what I said in grandparent post. I know Conor's views on total programming and share them, but the 2015 comment is not particularly relevant to the current topic, nor does it reflect on the folklore self-interpreter argument.
  - mietek 9y ago
    It is great that you are interested in the subject. Please consider joining ##dependent on Freenode IRC.

f :: String -> () f g' = case (eval g' :: Maybe (String -> ())) of Just g -> g g' Nothing -> () loop :: () loop = f (quote f)

by Kutta 9y ago

f :: String -> () f g' = case (eval g' :: Maybe (String -> ())) of Just g -> g g' Nothing -> () loop :: () loop = f (quote f)

mietek 9y ago

Your sketch of a proof does not appear substantially different from the proof given in section 3.1 of the linked paper. Section 3.2 explains that this result does not apply to strongly normalising languages. See also the slides titled “So what about, e.g. Fω instead of ℕ ⇒ ℕ?” in Gergo Erdi’s talk on the subject of the linked paper: https://gergo.erdi.hu/talks/2015-11-fomega/FOmegaUnquote.pdf https://gergo.erdi.hu/talks/2015-11-fomega/FOmegaUnquote.pdf Note that your sketch is one particular variation of a folklore argument, best recalled by Conor McBride in 2003: https://mail.haskell.org/pipermail/haskell-cafe/2003-May/004343.html https://mail.haskell.org/pipermail/haskell-cafe/2003-May/004... Here’s what Conor McBride has to say on the subject in 2015: https://www.reddit.com/r/haskell/comments/38wels/conor_mcbride_hasochistic_containers/cs11ppm/?context=3 https://www.reddit.com/r/haskell/comments/38wels/conor_mcbri... If you are interested in discussing this further, please feel free to contact me privately.

Kutta 9y ago
I am familiar with all of your listed sources (even attended one incarnation of the Érdi Gergő talk). Section 3.2 of the paper absolutely does not say that the result does not hold. The main point of the construction is that typed quoted representations can preserve totality by disallowing diagonal application. Interpreting untyped quoted representations is impossible all the same, which is what I said in grandparent post. I know Conor's views on total programming and share them, but the 2015 comment is not particularly relevant to the current topic, nor does it reflect on the folklore self-interpreter argument.
- mietek 9y ago
  It is great that you are interested in the subject. Please consider joining ##dependent on Freenode IRC.