RosettaCodeData/Task/Detect-division-by-zero/D/detect-division-by-zero.d

54 lines
1.9 KiB
D

import std.stdio, std.string, std.math, std.traits;
string divCheck(T)(in T numer, in T denom)
if (isIntegral!T || isFloatingPoint!T) {
Unqual!(typeof(numer / denom)) result;
string msg;
static if (isIntegral!T) {
try {
result = numer / denom;
} catch(Error e) {
msg = "| " ~ e.msg ~ " (by Error)";
result = T.max;
}
} else { // Floating Point Type.
result = numer / denom;
if (numer.isNormal && result.isInfinity) {
msg = "| Division by Zero";
} else if (result != 0 && !result.isNormal) {
if (numer.isNaN)
msg = "| NaN numerator";
else if (denom.isNaN)
msg = "| NaN denominator";
else if (numer.isInfinity)
msg = "| Inf numerator";
else
msg = "| NaN (Zero Division by Zero)";
}
}
return format("%5s %s", format("%1.1g", real(result)), msg);
}
void main() {
writeln("Division with check:");
writefln("int 1/ 0: %s", divCheck(1, 0));
writefln("ubyte 1/ 0: %s", divCheck(ubyte(1), ubyte(0)));
writefln("real 1/ 0: %s", divCheck(1.0L, 0.0L));
writefln("real -1/ 0: %s", divCheck(-1.0L, 0.0L));
writefln("real 0/ 0: %s", divCheck(0.0L, 0.0L));
writeln;
writefln("real -4/-2: %s", divCheck(-4.0L,-2.0L));
writefln("real 2/-inf: %s", divCheck(2.0L, -real.infinity));
writeln;
writefln("real -inf/-2: %s", divCheck(-real.infinity, -2.0L));
writefln("real +inf/-2: %s", divCheck(real.infinity, -2.0L));
writefln("real nan/-2: %s", divCheck(real.nan, -2.0L));
writefln("real -2/ nan: %s", divCheck(-2.0L, real.nan));
writefln("real nan/ 0: %s", divCheck(real.nan, 0.0L));
writefln("real inf/ inf: %s",
divCheck(real.infinity, real.infinity));
writefln("real nan/ nan: %s", divCheck(real.nan, real.nan));
}