Christian Maeder schrieb: [...] > Without this restriction polynomials like > "- a + - b * x + - c * - x ^ 2" > would uniquely resolve to > "((- a) + (- (b * x))) + (- (c * (- (x ^ 2))))" > > I think hugs handles this correctly!
yes it does this case. > > Let us assume a user-defined (non- or) right-associative operator "#" > with the same precedence as "+" and "-" (infix[r] 6 #). > > 3.c) both "- a # b" and "a # - b" are rejected, > because "#" is not left-associative (like "-"). hugs rejects only the case "- a # b": ERROR - Ambiguous use of unary minus with "(#)" So hugs still considers associativity for "-" (but does not consider the operator to the left of an unary minus.) C. > This unnecessary restriction rules out a (user-defined) polynomial like > "- a # - b * x" _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime
