update

Task/Non-decimal-radices-Convert/D/non-decimal-radices-convert-3.d

@@ -0,0 +1,36 @@
+import std.stdio, std.conv, std.algorithm, std.exception, std.ascii,
+       std.array;
+
+alias Digits = ubyte[];
+
+Digits toBase(ulong number, in ubyte base) pure nothrow {
+    Digits result;
+    while (number) {
+        result = number % base ~ result;
+        number /= base;
+    }
+    return result;
+}
+
+ulong fromBase(in Digits digits, in ubyte base) pure nothrow {
+    return reduce!((n, k) => n * base + k)(0, digits);
+}
+
+string fromDigits(in Digits digits) pure nothrow {
+    return digits
+           .map!(d => cast(char)(d < 10 ? d + '0' : d + 'a' - 10))
+           .array;
+}
+
+Digits toDigits(in string number) pure /*nothrow*/ {
+    static ubyte convert(in dchar d) pure nothrow {
+        if (d.isDigit) return cast(typeof(return))(d - '0');
+        if (d.isUpper) return cast(typeof(return))(d - 'A' + 10);
+        else           return cast(typeof(return))(d - 'a' + 10);
+    }
+    return number.map!convert.array;
+}
+
+void main() {
+    "1ABcd".toDigits.fromBase(16).writeln;
+}