Ticket #1325: canonical-xsdouble.patch

FUStringBuilder.hpp

@@ -26 +26 @@
 #define SAFE_DELETE_ARRAY(ptr) if (ptr != NULL) { delete [] ptr; ptr = NULL; }
 #endif
 
-template <class Char, class FloatType>
-void FloatToString(FloatType f, Char* sz)
-{
-    Char* buffer = sz + 1;
-    static const int digitCount = 6;
-    int decimal, sign;
-
-    // ecvt rounds the string for us: http://www.datafocus.com/docs/man3/ecvt.3.asp
-    char* end = ecvt(f, digitCount, &decimal, &sign);
-
-    if (sign != 0) (*buffer++) = '-';
-    int count = digitCount;
-    if (decimal > digitCount)
-    {
-        // We use the scientific notation: P.MeX
-        (*buffer++) = (*end++); // P is one character.
-        (*buffer++) = '.';
-
-        // Mantissa (cleaned for zeroes)
-        for (--count; count > 0; --count) if (end[count - 1] != '0') break;
-        for (int i = 0; i < count; ++i) (*buffer++) = (*end++);
-        if (buffer[-1] == '.') --buffer;
-
-        // Exponent
-        (*buffer++) = 'e';
-        uint32 exponent = decimal - 1; // X
-        if (exponent >= 10) (*buffer++) = (Char) ('0' + (exponent / 10));
-        (*buffer++) = (Char) ('0' + (exponent % 10));
-        (*buffer) = 0;
-        return;
-    }
-    else if (decimal > 0)
-    {
-        // Simple number: A.B
-        for (int i = 0; i < decimal; ++i) (*buffer++) = (*end++);
-        if (decimal < digitCount) (*buffer++) = '.';
-        count = digitCount - decimal;
-    }
-    else if (decimal < -digitCount)
-    {
-        // What case is this?
-        decimal = count = 0;
-    }
-    else if (decimal < 0 || (decimal == 0 && *end != '0'))
-    {
-        // Tiny number: 0.Me-X
-        (*buffer++) = '0'; (*buffer++) = '.';
-        for (int i = 0; i < -decimal; ++i) (*buffer++) = '0';
-        count = digitCount + decimal;
-    }
-    for (; count > 0; --count) if (end[count - 1] != '0') break;
-    for (int i = 0; i < count; ++i) (*buffer++) = (*end++);
-    if (decimal == 0 && count == 0) (*buffer++) = '0';
-    if (buffer[-1] == '.') --buffer;
-    (*buffer) = 0;
-}
-
 template <class Char>
 FUStringBuilderT<Char>::FUStringBuilderT(const String& sz)
 {
@@ -234 +177 @@
 template <class Char>
 void FUStringBuilderT<Char>::append(float f)
 {
-#ifdef WIN32
-    // use <float.h> _isnan method to detect the 1.#IND00 NaN.
-    if (f != std::numeric_limits<float>::infinity() && f != -std::numeric_limits<float>::infinity() && f != std::numeric_limits<float>::quiet_NaN() && f != std::numeric_limits<float>::signaling_NaN() && !_isnan((double)f))
-#else
-    if (f != std::numeric_limits<float>::infinity() && f != -std::numeric_limits<float>::infinity() && f != std::numeric_limits<float>::quiet_NaN() && f != std::numeric_limits<float>::signaling_NaN())
-#endif
-    {
-        if (IsEquivalent(f, 0.0f, std::numeric_limits<float>::epsilon())) append((Char)'0');
-        else
-        {
-            Char sz[128];
-            FloatToString(f, sz);
-            append(sz + 1);
-        }
-    }
-    else if (f == std::numeric_limits<float>::infinity())
-    { append((Char)'I'); append((Char)'N'); append((Char)'F'); }
-    else if (f == -std::numeric_limits<float>::infinity())
-    { append((Char)'-'); append((Char)'I'); append((Char)'N'); append((Char)'F'); }
-    else
-    { append((Char)'N'); append((Char)'a'); append((Char)'N'); }
+    append((double)f);
 }
 
 template <class Char>
 void FUStringBuilderT<Char>::append(double f)
 {
-#ifdef WIN32
-    // use <float.h> _isnan method to detect the .#IND00 NaN.
-    if (f != std::numeric_limits<float>::infinity() && f != -std::numeric_limits<float>::infinity() && f != std::numeric_limits<float>::quiet_NaN() && f != std::numeric_limits<float>::signaling_NaN() && !_isnan(f))
-#else
-    if (f != std::numeric_limits<float>::infinity() && f != -std::numeric_limits<float>::infinity() && f != std::numeric_limits<float>::quiet_NaN() && f != std::numeric_limits<float>::signaling_NaN())
-#endif
-    {
-        if (IsEquivalent(f, 0.0, std::numeric_limits<double>::epsilon())) append((Char)'0');
-        else
-        {
-            Char sz[128];
-            FloatToString(f, sz);
-            append(sz + 1);
-        }
+    if (f == -std::numeric_limits<double>::infinity()) {
+        append("-INF");
+        return;
+    } else if (f == std::numeric_limits<double>::infinity()) {
+        append("INF");
+        return;
+    } else if (f != f) {
+        append("NaN");
+        return;
+    } else if (-std::numeric_limits<double>::epsilon() < f && f < std::numeric_limits<double>::epsilon()) {
+        append("0.0E0");
+        return;
+    }
+
+    if (f < 0.0) {
+        f = -f;
+        append('-');
     }
-    else if (f == std::numeric_limits<double>::infinity())
-    { append((Char)'I'); append((Char)'N'); append((Char)'F'); }
-    else if (f == -std::numeric_limits<double>::infinity())
-    { append((Char)'-'); append((Char)'I'); append((Char)'N'); append((Char)'F'); }
+
+    int e = 0;
+//  e = floor(log10(f));
+//  f = f / pow(10.0, e);
+
+    if (f < 1.0)
+        for (; f < 1.0; f *= 10.0)
+            e--;
     else
-    { append((Char)'N'); append((Char)'a'); append((Char)'N'); }
+        for (; f >= 10.0; f /= 10.0)
+            e++;
+
+    char tmp[10];
+    sprintf(tmp, "%.6g", f);
+    append(tmp);
+    if (tmp[1] == 0) // only one digit, add missing part according canonical representation
+        append(".0");
+
+    sprintf(tmp, "E%d", e);
+    append(tmp);
 }
 
 template <class Char>