X-Git-Url: http://git.tdb.fi/?p=libs%2Fcore.git;a=blobdiff_plain;f=source%2Fstrings%2Flexicalcast.cpp;fp=source%2Fstrings%2Flexicalcast.cpp;h=5903bb1197d6364382714dd4f1772b477844b919;hp=0000000000000000000000000000000000000000;hb=b42ed73a1b241c0e93ee03c43c4584b41c549bac;hpb=5b1368cb791cab043f0435628cacbaff36e39b7b

diff --git a/source/strings/lexicalcast.cpp b/source/strings/lexicalcast.cpp
new file mode 100644
index 0000000..5903bb1
--- /dev/null
+++ b/source/strings/lexicalcast.cpp
@@ -0,0 +1,623 @@
+/* $Id$
+
+This file is part of libmspstrings
+Copyright © 2006-2008 Mikko Rasa
+Distributed under the LGPL
+*/
+
+#include <cmath>
+#include <limits>
+#include "lexicalcast.h"
+
+using namespace std;
+
+namespace {
+
+using namespace Msp;
+
+template<typename T>
+struct IsSigned
+{ enum { result = !(static_cast<T>(-1)>0) }; };
+
+template<typename T, bool f = (sizeof(T)>sizeof(unsigned long))>
+struct Temporary
+{ typedef unsigned long Type; };
+
+template<typename T>
+struct Temporary<T, true>
+{
+#ifdef WIN32
+	typedef __int64 Type;
+#else
+	typedef unsigned long long Type;
+#endif
+};
+
+/* Helper to avoid warnings about an unsigned type never being < 0 */
+template<typename T, bool f = IsSigned<T>::result>
+struct IsNegative
+{ static bool eval(T v) { return v<0; } };
+
+template<typename T>
+struct IsNegative<T, false>
+{ static bool eval(T) { return false; } };
+
+/* Helper to avoid errors about ambiguous function calls since there are no
+overloads of abs for unsigned types */
+template<typename T, bool f = IsSigned<T>::result>
+struct Absolute
+{ static T eval(T v) { return v<0 ? -v : v; } };
+
+template<typename T>
+struct Absolute<T, false>
+{ static T eval(T v) { return v; } };
+
+
+/*** Integer conversions ***/
+
+const char udigits[] = "0123456789ABCDEF";
+const char ldigits[] = "0123456789abcdef";
+
+template<typename T>
+char *int_to_str(T v, const Fmt &f, char *end)
+{
+	if(f.get_type()==Fmt::CHAR)
+	{
+		*--end = v;
+		return end;
+	}
+
+	char *ptr = end;
+
+	// Find out the base to use
+	unsigned base = f.get_base();
+	if(!base)
+		base = 10;
+
+	// Format the number, starting from the least significant digit
+	const char *digits = (f.get_uppercase() ? udigits : ldigits);
+	if(v)
+	{
+		typename Temporary<T>::Type w = Absolute<T>::eval(v);
+		while(w)
+		{
+			*--ptr = digits[w%base];
+			w /= base;
+		}
+	}
+	else
+		*--ptr = digits[0];
+
+	char sign = (IsNegative<T>::eval(v) ? '-' : f.get_showpos() ? '+' : 0);
+	if(f.get_fill()=='0')
+	{
+		/* Zero-fill, taking base/sign size into account.  The expression is a
+		bit ugly, but saves having to write code for creating the prefix both
+		ways. */
+		unsigned pfxsize = ((f.get_showbase() && base!=10) ? base==8 ? 1 : 2 : 0) + (sign!=0);
+		for(unsigned i=(end-ptr)+pfxsize; i<f.get_width(); ++i)
+			*--ptr = '0';
+	}
+
+	if(f.get_showbase() && v!=0)
+	{
+		// Add base indicator
+		if(base==2)
+			*--ptr = (f.get_uppercase() ? 'B' : 'b');
+		else if(base==16)
+			*--ptr = (f.get_uppercase() ? 'X' : 'x');
+		if(base!=10)
+			*--ptr = '0';
+	}
+
+	if(sign)
+		*--ptr = sign;
+
+	return ptr;
+}
+
+template<typename T>
+string int_to_str(T v, const Fmt &f)
+{
+	unsigned size = max(f.get_width(), max<unsigned>(f.get_precision(), sizeof(T)*8+3));
+	char *buf = new char[size];
+	string result(int_to_str(v, f, buf+size), buf+size);
+	delete[] buf;
+	return result;
+}
+
+template<typename T>
+T str_to_int(const std::string &s, const Fmt &f)
+{
+	if(s.empty())
+		throw LexicalError("Empty input in integer conversion");
+
+	std::string::const_iterator i = s.begin();
+
+	// See if the input starts with a sign
+	bool neg = false;
+	if(*i=='-')
+	{
+		if(!IsSigned<T>::result)
+			throw LexicalError("Negative sign in unsigned integer conversion");
+		neg = true;
+		++i;
+	}
+	else if(*i=='+')
+		++i;
+
+	// Must have some digits to convert
+	if(i==s.end())
+		throw LexicalError("Missing digits in integer conversion");
+
+	T base = f.get_base();
+	if(!base && i!=s.end())
+	{
+		// Automatic base detection requested, figure it out
+		if(*i=='0' && ++i!=s.end())
+		{
+			if(*i=='x' || *i=='X')
+			{
+				base = 16;
+				++i;
+			}
+			else if(*i=='b' || *i=='B')
+			{
+				base = 2;
+				++i;
+			}
+			else
+				base = 8;
+		}
+		else
+			base = 10;
+	}
+
+	// Parse the digits
+	T result = 0;
+	for(; i!=s.end(); ++i)
+	{
+		T digit = base;
+		if(*i>='0' && *i<='9')
+			digit = *i-'0';
+		else if(*i>='A' && *i<='F')
+			digit = *i-'A'+10;
+		else if(*i>='a' && *i<='f')
+			digit = *i-'a'+10;
+		if(digit>=base)
+			throw LexicalError("Invalid digit in integer conversion");
+		T next = result*base+digit;
+		if(next/base!=result)
+			throw LexicalError("Overflow in integer conversion");
+		result = next;
+	}
+
+	if(neg)
+		result = -result;
+
+	return result;
+}
+
+
+/*** Boolean conversions ***/
+
+string bool_to_str(bool b, const Fmt &f)
+{
+	if(f.get_type()==Fmt::STR)
+		return b ? "true" : "false";
+	else
+		return b ? "1" : "0";
+}
+
+bool str_to_bool(const string &s)
+{
+	if(s.empty())
+		throw LexicalError("Empty input in boolean conversion");
+
+	if(s=="1" || s=="true" || s=="yes" || s=="on")
+		return true;
+	else if(s=="0" || s=="false" || s=="no" || s=="off")
+		return false;
+
+	throw LexicalError("Invalid input in boolean conversion");
+}
+
+
+/*** Floating-point conversions ***/
+
+template<typename T>
+string flt_to_str(T v, const Fmt &f)
+{
+	if(f.get_type()==Fmt::CHAR)
+		throw LexicalError("Character format in floating-point conversion");
+
+	Fmt::FloatMode mode = f.get_floatmode();
+	long double w = abs(v);
+	char sign = (v<0 ? '-' : f.get_showpos() ? '+' : 0);
+
+	// Handle infinity and not-a-number as special cases
+	if(!(w+w>w) && w!=0)
+	{
+		string result;
+		if(sign)
+			result += sign;
+		if(!(w>=0))
+			result += (f.get_uppercase() ? "NAN" : "nan");
+		else
+			result += (f.get_uppercase() ? "INF" : "inf");
+		if(result.size()<f.get_width())
+			result = string(f.get_width()-result.size(), ' ')+result;
+		return result;
+	}
+
+	/* Find out the base-10 exponent.  Building up the multiplier / divisor
+	first helps with accuracy in some cases. */
+	int exp = 0;
+	if(w>=10)
+	{
+		long double div = 1;
+		while(div*10<w)
+		{
+			++exp;
+			div *= 10;
+		}
+		w /= div;
+	}
+	else if(mode!=Fmt::FIXED && w<1 && w!=0)
+	{
+		long double mul = 1;
+		while(w*mul<1)
+		{
+			--exp;
+			mul *= 10;
+		}
+		w *= mul;
+	}
+
+	// Decide how to format the number
+	unsigned digits;
+	unsigned point = 1;
+	bool showexp = false;
+	if(mode==Fmt::FIXED)
+	{
+		point = exp+1;
+		digits = point+f.get_precision();
+	}
+	else if(mode==Fmt::SCI)
+	{
+		digits = f.get_precision()+1;
+		showexp = true;
+	}
+	else
+	{
+		digits = max(f.get_precision(), 1U);
+		if(exp<-4 || exp>=static_cast<int>(digits))
+		{
+			point = 1;
+			showexp = true;
+		}
+		else
+		{
+			point = max(exp, 0)+1;
+			if(exp<0)
+				digits += -exp;
+		}
+	}
+
+	// Apply rounding
+	w += 5.0l/pow(10.0l, static_cast<long double>(digits));
+	if(w>10)
+	{
+		// Rounding bumped us to the next exponent, deal with it
+		w /= 10;
+		if(mode==Fmt::AUTOFLT && exp+1==static_cast<int>(digits))
+		{
+			point = 1;
+			showexp = true;
+		}
+		if(!showexp)
+		{
+			++digits;
+			++point;
+		}
+		else
+			++exp;
+	}
+
+	// Create a buffer and start from the end
+	unsigned size = max(f.get_width(), digits+8);
+	char *buf = new char[size];
+	char *end = buf+size;
+	char *ptr = end;
+
+	// Format exponent
+	if(showexp)
+	{
+		ptr = int_to_str(exp, Fmt().showpos().fill('0').width(3), ptr);
+		*--ptr = (f.get_uppercase() ? 'E' : 'e');
+	}
+
+	// Format mantissa left-to-right
+	char *eptr = ptr;
+	ptr -= digits+(point<digits || f.get_showpoint());
+	char *mptr = ptr;
+	for(unsigned i=0; i<digits; ++i)
+	{
+		if(i==point)
+			*mptr++ = '.';
+		if(showexp || static_cast<int>(i)>=-exp)
+		{
+			int digit = static_cast<int>(w);
+			*mptr++ = '0'+digit;
+			w = (w-digit)*10;
+		}
+		else
+			*mptr++ = '0';
+	}
+
+	if(f.get_showpoint())
+	{
+		// Radix point requested but not displayed yet, add it
+		if(digits<=point)
+			*mptr++ = '.';
+	}
+	else if(mode==Fmt::AUTOFLT && digits>point)
+	{
+		// Remove trailing zeroes from fraction and a lone radix point
+		while(mptr[-1]=='0')
+			--mptr;
+		if(mptr[-1]=='.')
+			--mptr;
+		if(mptr!=eptr)
+		{
+			while(mptr!=ptr)
+				*--eptr = *--mptr;
+			ptr = eptr;
+		}
+	}
+
+	// Add filling and sign
+	if(f.get_fill()=='0')
+	{
+		unsigned pfxlen = (sign!=0);
+		while(end-ptr+pfxlen<f.get_width())
+			*--ptr = '0';
+	}
+	if(sign)
+		*--ptr = sign;
+
+	string result(ptr, end);
+	delete[] buf;
+	return result;
+}
+
+template<typename T>
+T str_to_flt(const string &s, const Fmt &)
+{
+	if(s.empty())
+		throw LexicalError("Empty input in floating-point conversion");
+
+	std::string::const_iterator i = s.begin();
+
+	// See if the input starts with a sign
+	bool neg = false;
+	if(*i=='-')
+	{
+		neg = true;
+		++i;
+	}
+	else if(*i=='+')
+		++i;
+
+	// Must have some digits to convert
+	if(i==s.end())
+		throw LexicalError("Missing digits in floating-point conversion");
+
+	long double v = 0;
+	int exp = 0;
+
+	// Parse mantissa
+	bool point_seen = false;
+	for(; i!=s.end(); ++i)
+	{
+		if(*i=='.')
+		{
+			if(point_seen)
+				throw LexicalError("Extra point in floating-point conversion");
+			point_seen = true;
+		}
+		else if(*i>='0' && *i<='9')
+		{
+			v = v*10+(*i-'0');
+			if(point_seen)
+				--exp;
+		}
+		else if(*i=='e' || *i=='E')
+		{
+			// We have an exponent
+			++i;
+
+			exp += str_to_int<int>(string(i, s.end()), Fmt());
+			// str_to_int has eaten the rest of the input or thrown
+			break;
+		}
+		else
+			throw LexicalError("Invalid digit in floating-point conversion");
+	}
+
+	// Scale and negate the result as needed
+	while(exp>0)
+	{
+		v *= 10;
+		--exp;
+	}
+	while(exp<0)
+	{
+		v /= 10;
+		++exp;
+	}
+
+	if(neg)
+		v = -v;
+
+	return v;
+}
+
+
+/*** String conversions ***/
+
+string str_to_str(const string &s, const Fmt &f)
+{
+	if(f.get_type()==Fmt::NUM)
+		throw LexicalError("Numeric format in string conversion");
+	return s;
+}
+
+}
+
+namespace Msp {
+
+void LexicalConverter::result(const string &s)
+{
+	if(s.size()<fmt.get_width())
+	{
+		if(fmt.get_align()==Fmt::RIGHT)
+			buf = string(fmt.get_width()-s.size(), fmt.get_fill())+s;
+		else
+			buf = s+string(fmt.get_width()-s.size(), fmt.get_fill());
+	}
+	else
+		buf = s;
+}
+
+
+/*** operator<< ***/
+
+void operator<<(LexicalConverter &c, char v)
+{
+	Fmt::Type type = c.get_fmt().get_type();
+	if(type==Fmt::NUM)
+		c.result(int_to_str(v, c.get_fmt()));
+	else
+		c.result(string(1, v));
+}
+
+void operator<<(LexicalConverter &c, signed char v)
+{ c.result(int_to_str(v, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, short v)
+{ c.result(int_to_str(v, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, int v)
+{ c.result(int_to_str(v, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, long v)
+{ c.result(int_to_str(v, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, unsigned char v)
+{ c.result(int_to_str(v, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, unsigned short v)
+{ c.result(int_to_str(v, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, unsigned v)
+{ c.result(int_to_str(v, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, unsigned long v)
+{ c.result(int_to_str(v, c.get_fmt())); }
+
+#ifdef __GNUC__
+void operator<<(LexicalConverter &c, long long v)
+{ c.result(int_to_str(v, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, unsigned long long v)
+{ c.result(int_to_str(v, c.get_fmt())); }
+#endif
+
+void operator<<(LexicalConverter &c, bool v)
+{ c.result(bool_to_str(v, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, float v)
+{ c.result(flt_to_str(v, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, double v)
+{ c.result(flt_to_str(v, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, long double v)
+{ c.result(flt_to_str(v, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, const string &s)
+{ c.result(str_to_str(s, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, const char *s)
+{ c.result(str_to_str(s, c.get_fmt())); }
+
+void operator<<(LexicalConverter &c, const void *p)
+{ c.result(int_to_str(reinterpret_cast<unsigned long>(p), c.get_fmt())); }
+
+
+/*** operator>> ***/
+
+void operator>>(const LexicalConverter &c, char &v)
+{
+	if(c.get_fmt().get_type()==Fmt::NUM)
+		v = str_to_int<char>(c.get(), c.get_fmt());
+	else
+	{
+		const std::string &s = c.get();
+		if(s.empty())
+			throw LexicalError("Empty input in character conversion");
+		if(s.size()>1)
+			throw LexicalError("Extra input in character conversion");
+		v = s[0];
+	}
+}
+
+void operator>>(const LexicalConverter &c, signed char &v)
+{ v = str_to_int<signed char>(c.get(), c.get_fmt()); }
+
+void operator>>(const LexicalConverter &c, short &v)
+{ v = str_to_int<short>(c.get(), c.get_fmt()); }
+
+void operator>>(const LexicalConverter &c, int &v)
+{ v = str_to_int<int>(c.get(), c.get_fmt()); }
+
+void operator>>(const LexicalConverter &c, long &v)
+{ v = str_to_int<long>(c.get(), c.get_fmt()); }
+
+void operator>>(const LexicalConverter &c, unsigned char &v)
+{ v = str_to_int<unsigned char>(c.get(), c.get_fmt()); }
+
+void operator>>(const LexicalConverter &c, unsigned short &v)
+{ v = str_to_int<unsigned short>(c.get(), c.get_fmt()); }
+
+void operator>>(const LexicalConverter &c, unsigned int &v)
+{ v = str_to_int<unsigned int>(c.get(), c.get_fmt()); }
+
+void operator>>(const LexicalConverter &c, unsigned long &v)
+{ v = str_to_int<unsigned long>(c.get(), c.get_fmt()); }
+
+#ifdef __GNUC__
+void operator>>(const LexicalConverter &c, long long &v)
+{ v = str_to_int<long long>(c.get(), c.get_fmt()); }
+
+void operator>>(const LexicalConverter &c, unsigned long long &v)
+{ v = str_to_int<unsigned long long>(c.get(), c.get_fmt()); }
+#endif
+
+void operator>>(const LexicalConverter &c, bool &v)
+{ v = str_to_bool(c.get()); }
+
+void operator>>(const LexicalConverter &c, float &v)
+{ v = str_to_flt<float>(c.get(), c.get_fmt()); }
+
+void operator>>(const LexicalConverter &c, double &v)
+{ v = str_to_flt<double>(c.get(), c.get_fmt()); }
+
+void operator>>(const LexicalConverter &c, long double &v)
+{ v = str_to_flt<long double>(c.get(), c.get_fmt()); }
+
+void operator>>(const LexicalConverter &c, string &s)
+{ s = str_to_str(c.get(), c.get_fmt()); }
+
+} // namespace Msp