* One bug with the implementation of Real.fromDecimal (which also affects Real.scan and Real.fromString) in PolyML 5.2. The string_buffer[30] in Real_convc in <src>/libpolyml/reals.cpp limits the length of the string seen by strtod to 29 characters. However, the construction of the ML string at <src>/basis/Real.sml:359 can construct an arbitrarily large string. In particular, the "E" and exponent can be pushed beyond the end of the string seen by strtod:
Poly/ML 5.2 Release
Real.fromString "1234567890.12345678901234";
val it = SOME 1234567890.0 : Real.real option
Real.fromString "1234567890.123456789012345";
val it = SOME 1.23456789 : Real.real option
Real.fromString "1234567890.1234567890123456";
val it = NONE : Real.real option
Real.fromString "1234567890.1234567890123456789";
val it = SOME 0.123456789 : Real.real option * Real.~ doesn't properly flip the sign bit on zero: Poly/ML 5.2 Release
Real.signBit 0.0;
val it = false : bool
Real.signBit (Real.~ 0.0);
val it = false : bool
Real.signBit 1.0;
val it = false : bool
Real.signBit (Real.~ 1.0);
val it = true : bool This, in turn, makes 'Real.fromString "~0.0"' get the sign bit wrong:
Real.signBit (valOf (Real.fromString "~0.0"));
val it = false : bool _______________________________________________ polyml mailing list polyml@inf.ed.ac.uk http://lists.inf.ed.ac.uk/mailman/listinfo/polyml
