X-Git-Url: https://mattmccutchen.net/bigint/bigint.git/blobdiff_plain/e257a1b25b880dc6246189e7ede1d0ea3db6337d..refs/heads/no-explicit-template-args:/BigUnsignedInABase.cc

diff --git a/BigUnsignedInABase.cc b/BigUnsignedInABase.cc
index 22fca51..c849014 100644
--- a/BigUnsignedInABase.cc
+++ b/BigUnsignedInABase.cc
@@ -1,19 +1,19 @@
-/*
-* Matt McCutchen's Big Integer Library
-* http://mysite.verizon.net/mccutchen/bigint/
-*/
+#include "BigUnsignedInABase.hh"
 
-/*
-* Milan Tomic had trouble compiling this file on Microsoft
-* Visual C++ 6 because, in the libraries that come with
-* Visual C++ 6, the `std::string::push_back' method apparently
-* does not exist.  To get around the problem, I rewrote
-* `BigUnsignedInABase::operator std::string' (at the bottom
-* of this file) so it doesn't use `push_back'.
-*/
+BigUnsignedInABase::BigUnsignedInABase(const Digit *d, Index l, Base base)
+	: NumberlikeArray<Digit>(d, l), base(base) {
+	// Check the base
+	if (base < 2)
+		throw "BigUnsignedInABase::BigUnsignedInABase(const Digit *, Index, Base): The base must be at least 2";
 
-#include "BigUnsignedInABase.hh"
-#include <iostream>
+	// Validate the digits.
+	for (Index i = 0; i < l; i++)
+		if (blk[i] >= base)
+			throw "BigUnsignedInABase::BigUnsignedInABase(const Digit *, Index, Base): A digit is too large for the specified base";
+
+	// Eliminate any leading zeros we may have been passed.
+	zapLeadingZeros();
+}
 
 namespace {
 	unsigned int bitLen(unsigned int x) {
@@ -28,41 +28,35 @@ namespace {
 		return (a + b - 1) / b;
 	}
 }
-	/*std::cout << "((( BigUnsigned ==> BigUnsignedInABase\n";
-	std::cout << "[ Parameter BigUnsigned @ " << (void *)(NumberlikeArray<BigUnsigned::Blk> *)(&x)
-		<< ",\nresulting BigUnsignedInABase @ " << (void *)(NumberlikeArray<Digit> *)(this) << "]" << std::endl;*/
-BigUnsignedInABase::BigUnsignedInABase(const BigUnsigned &x, Base base) {
 
+BigUnsignedInABase::BigUnsignedInABase(const BigUnsigned &x, Base base) {
 	// Check the base
 	if (base < 2)
 		throw "BigUnsignedInABase(BigUnsigned, Base): The base must be at least 2";
-	// Save the base.
-	// This pattern is seldom seen in C++, but the analogous ``this.'' is common in Java.
 	this->base = base;
-	
+
 	// Get an upper bound on how much space we need
 	int maxBitLenOfX = x.getLength() * BigUnsigned::N;
 	int minBitsPerDigit = bitLen(base) - 1;
 	int maxDigitLenOfX = ceilingDiv(maxBitLenOfX, minBitsPerDigit);
-	len = maxDigitLenOfX; // Another change to comply with `staying in bounds'; see `BigUnsigned::divideWithRemainder'.
+	len = maxDigitLenOfX; // Another change to comply with `staying in bounds'.
 	allocate(len); // Get the space
-	
+
 	BigUnsigned x2(x), buBase(base);
 	Index digitNum = 0;
-	
+
 	while (!x2.isZero()) {
 		// Get last digit.  This is like `lastDigit = x2 % buBase, x2 /= buBase'.
 		BigUnsigned lastDigit(x2);
 		lastDigit.divideWithRemainder(buBase, x2);
 		// Save the digit.
-		blk[digitNum] = Digit(lastDigit); // invokes `BigUnsigned ==> unsigned short' converter
+		blk[digitNum] = lastDigit.toUnsignedShort();
 		// Move on.  We can't run out of room: we figured it out above.
 		digitNum++;
 	}
-	
+
 	// Save the actual length.
 	len = digitNum;
-	/*std::cout << "BigUnsigned ==> BigUnsignedInABase )))\n";*/
 }
 
 BigUnsignedInABase::operator BigUnsigned() const {
@@ -83,10 +77,12 @@ BigUnsignedInABase::BigUnsignedInABase(const std::string &s, Base base) {
 	// Save the base.
 	// This pattern is seldom seen in C++, but the analogous ``this.'' is common in Java.
 	this->base = base;
-	
-	len = s.length();
+
+	// `s.length()' is a `size_t', while `len' is a `NumberlikeArray::Index',
+	// also known as an `unsigned int'.  Some compilers warn without this cast.
+	len = Index(s.length());
 	allocate(len);
-	
+
 	Index digitNum, symbolNumInString;
 	for (digitNum = 0; digitNum < len; digitNum++) {
 		symbolNumInString = len - 1 - digitNum;
@@ -104,11 +100,11 @@ BigUnsignedInABase::BigUnsignedInABase(const std::string &s, Base base) {
 }
 
 BigUnsignedInABase::operator std::string() const {
-	//std::cout << "((( BigUnsignedInABase ==> std::string\n";
 	if (base > 36)
 		throw "BigUnsignedInABase ==> std::string: The default string conversion routines use the symbol set 0-9, A-Z and therefore support only up to base 36.  You tried a conversion with a base over 36; write your own string conversion routine.";
 	if (len == 0)
 		return std::string("0");
+	// Some compilers don't have push_back, so use a char * buffer instead.
 	char *s = new char[len + 1];
 	s[len] = '\0';
 	Index digitNum, symbolNumInString;
@@ -121,7 +117,6 @@ BigUnsignedInABase::operator std::string() const {
 			s[symbolNumInString] = char('A' + theDigit - 10);
 	}
 	std::string s2(s);
-	delete s;
-	//std::cout << "BigUnsignedInABase ==> std::string )))\n";
+	delete [] s;
 	return s2;
 }