[Haskell-cafe] What to call Occult Effects

[Sergey Goncharov]

Dear Olaf and everyone,

the law do {_ <- b; a} = a is equivalent to do {_ <- b; return ()} = return (), for, assuming the latter,

	  do {_ <- b; a}
  	= do {_ <- do {_ <- b; return ()}; a}
  	= do {_ <- return (); a}
	= a

and it does actually have some history. It was dubbed 'discardability' by Thielecke [1] and explored by 
Führmann in [2] together with some other important properties of effects, such as 'centrality' and 
'commutativity'. Combinations of these properties and examples are explored in the conventional 
Haskell-like style in [3] (where 'discardability' is called 'side-effect freeness' though).

Cheers,
Sergey

[1] H. Thielecke, Categorical structure of continuation passing style, Ph.D. Thesis, University of 
Edinburgh, 1997.

[2] C. Führmann, Varieties of effects, in: M. Nielsen, U. Engberg (Eds.), Foundations of Software 
Science and Computation Structures, FOSSACS 2002, in: Lect. Notes Comput. Sci., vol. 2303, Springer, 
2002, pp. 144–158.

[3] L. Schröder, T. Mossakowski, Monad-independent dynamic logic in HasCasl, J. Logic Comput. 14 (2004) 
571–619

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 5384 bytes
Desc: S/MIME Cryptographic Signature
URL: <http://mail.haskell.org/pipermail/haskell-cafe/attachments/20201113/259695ba/attachment.bin>