RosettaCodeData/Task/Non-decimal-radices-Convert/D/non-decimal-radices-convert-2.d
Ingy döt Net 776bba907c Sync
2013-10-27 22:24:23 +00:00

62 lines
1.7 KiB
D

import std.stdio, std.array, std.ascii;
immutable string mDigits = digits ~ lowercase;
ulong atoiRadix(in string str, in uint radix=10, int* consumed=null)
nothrow {
static int dtoi(in char dc, in uint radix) nothrow {
static int[immutable char] digit;
immutable char d = dc.toLower;
if (digit.length == 0) // Not init yet.
foreach (i, c; mDigits)
digit[c] = i;
if (radix > 1 && radix <= digit.length &&
d in digit && digit[d] < radix)
return digit[d];
return int.min; // A negative for error.
}
ulong result;
int sp;
for (; sp < str.length; sp++) {
immutable int d = dtoi(str[sp], radix);
if (d >= 0) // Valid digit char.
result = radix * result + d;
else
break;
}
if (sp != str.length) // Some char in str not converted.
sp = -sp;
if (consumed !is null) // Signal error if not positive.
*consumed = sp;
return result;
}
string itoaRadix(ulong num, in uint radix=10) pure nothrow
in {
assert(radix > 1 && radix <= mDigits.length);
} body {
string result;
while (num > 0) {
immutable uint d = num % radix;
result = mDigits[d] ~ result;
num = (num - d) / radix;
}
return result.empty ? "0" : result;
}
void main() {
immutable string numStr = "1ABcdxyz???";
int ate;
writef("'%s' (base %d) = %d", numStr, 16,
atoiRadix(numStr, 16, &ate));
if (ate <= 0)
writefln("\tConverted only: '%s'", numStr[0 .. -ate]);
else
writeln();
writeln(itoaRadix(60_272_032_366, 36), " ",
itoaRadix(591_458, 36));
}