Atze Dijkstra schrieb:
Hi,
I prefer the simplicity of http://hackage.haskell.org/trac/haskell-prime/wiki/NegationBindsTightly over the more involved proposal.
It's a simple design choice but hard to put into practice for compatibility reasons. It is an old design choice between fortran and C style (earlier taken for Haskell) http://www.obliquity.com/computer/fortran/operate.html
I'd gladly pay the price of adding some parenthesis to force "- x ^ 2" to "- (x ^ 2)".
fortran and python have infix power operators that bind more tightly than unary minus. The mathematical unusual silent interpretation of "- x ^ 2" as "(- x) ^ 2" is the problem (and not that I better should write "- (x ^ 2)"). Other languages i.e. C do not have a power operator! Does "- pow x 2" read better? Leave it to users to define "^" and "**" as they like? Cheers Christian This is also much more clearer, less dependent on context info (i.e. the fixity of other operators), thus understandable without inspecting the definition of ^ in some other module, and thus also easier to explain (to students), and thus lessening the steepness of Haskells learning curve somewhat.
cheers,
On 13 Jul, 2010, at 18:38 , Christian Maeder wrote:
Hi,
I'm asking for support of:
http://hackage.haskell.org/trac/haskell-prime/wiki/PrefixMinusResolution
Cheers Christian
Simon Marlow schrieb:
BTW, here's a related proposal made by Simon PJ earlier this year:
http://hackage.haskell.org/trac/haskell-prime/wiki/NegationBindsTightly
please consider merging the proposals, or at least clearly identifying the differences, if any.
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- Atze -
Atze Dijkstra, Department of Information and Computing Sciences. /|\ Utrecht University, PO Box 80089, 3508 TB Utrecht, Netherlands. / | \ Tel.: +31-30-2534118/1454 | WWW : http://www.cs.uu.nl/~atze . /--| \ Fax : +31-30-2513971 .... | Email: atze@cs.uu.nl ............ / |___\