Re: Preliminary Haskell 1.3 report now available

1996-03-08 Thread Fergus Henderson
Thomas Hallgren [EMAIL PROTECTED] writes: In the syntax for labeled fields (records) the symbol - is chosen as the operator used to associate a label with a value in constructions and patterns: [...] According to a committee member, there were no convincing reasons why - was chosen. Other

Re: Haskell 1.3

1996-03-08 Thread Philip Wadler
It looks ugly, but we could say that a data declaration does not have to have any constructors: data Empty = -- Lennart I agree that the best way to fix this is to have a form of data declaration with no constructors, but I'm not keen on the syntax you propose. How about if

Re: Haskell 1.3

1996-03-08 Thread Lennart Augustsson
Suggestion: Include among the basic types of Haskell a type `Empty' that contains no value except bottom. Absolutely! But I don't think it should be built in (unless absolutely necessary). It looks ugly, but we could say that a data declaration does not have to have any constructors:

Re: Haskell 1.3

1996-03-08 Thread Magnus Carlsson
Philip Wadler writes: It looks ugly, but we could say that a data declaration does not have to have any constructors: data Empty = -- Lennart I agree that the best way to fix this is to have a form of data declaration with no constructors, but I'm not keen on

Re: Haskell 1.3

1996-03-08 Thread Ron Wichers Schreur
Lennart Augustsson wrote: It looks ugly, but we could say that a data declaration does not have to have any constructors: data Empty = Philip Wadler responded: I'm not keen on the syntax you propose. How about if we allow the rhs of a data declaration to be just `empty', where

Haskell library proposal and constructor classes

1996-03-08 Thread Sven Panne
After browsing through the Standard Library Proposal for Haskell 1.3 (Version 3 from September 6, 1995), I have the following questions: 1) The proposal for collections (sec. 4.2) mentions four different _libraries_ which all define identical functions. IMHO, this should better

Haskell 1.3, monad expressions

1996-03-08 Thread smk
Suggestion: add another form of statement for monad expressions: stmts - ... if exp which is defined for MonadZero as follows: do {if exp ; stmts} = if exp then do {stmts} else zero Based on this, one can define list comprehensions by