Hi everyone,
I am new to the D programming language and decided to use it for
simple assignment. The idea is to compute the product of an
arbitrary number of numbers and print the result in a specific
way. The program needs to handle underflow/overflow, thus I
decided to use ieeeFlags. The program is found below.
Basically, the flags are not getting set. Changing the the
if-statements to check whether the resulting value is infinity or
0 (to test respectively for overflow/underflow) and it works. So
I am starting to think either I don't understand how this work,
or there is a bug.
Damien
/**********/
import std.stdio, std.exception, std.string, std.conv,
std.math;
void printProduct(in float[] numberList)
{
float tmp = 1.0f, product = 1.0f;
int exponent = 0;
foreach (number; numberList) {
resetIeeeFlags();
tmp *= number; // The variable tmp is used to
recover from errors.
if (ieeeFlags.overflow) {
writeln("lol");
while (product >= 1.0f) {
product /= 10.0f;
++exponent;
}
product *= number; // Impossible to
overflow anymore.
tmp = product;
} else if (ieeeFlags.underflow) {
while (product <= 1.0f) {
product *= 10.0f;
--exponent;
}
product *= number; // Impossible to
underflow anymore.
tmp = product;
} else {
product = tmp;
}
}
writeln(product, " times 10 to the power ", exponent,
".");
}
void main(string args[])
{
float[] numberList;
foreach (number; args[1..$]) {
enforce(isNumeric(number), "Only numeric
value are allowed as input.");
numberList ~= to!float(number);
}
writeln("The product is:");
printProduct(numberList);
}
