Put real formatting code into a separate function

This commit is contained in:
Eugen Wissner 2017-12-09 10:02:54 +01:00
parent 907f7a4e61
commit 2a68048fc1
1 changed files with 197 additions and 194 deletions

View File

@ -505,6 +505,202 @@ if (T.sizeof == U.sizeof)
copy((&src)[0 .. 1], (&dest)[0 .. 1]);
}
private void formatReal(T)(ref T arg ,ref String result)
if (isFloatingPoint!T)
{
char[512] buffer; // Big enough for e+308 or e-307.
char[8] tail = 0;
char[] bufferSlice = buffer[64 .. $];
uint precision = 6;
bool negative;
int decimalPoint;
// Read the double into a string.
auto realString = real2String(arg, buffer, decimalPoint, negative);
auto length = cast(uint) realString.length;
// Clamp the precision and delete extra zeros after clamp.
uint n = precision;
if (length > precision)
{
length = precision;
}
while ((length > 1) && (precision != 0) && (realString[length - 1] == '0'))
{
--precision;
--length;
}
if (negative)
{
result.insertBack('-');
}
if (decimalPoint == special)
{
result.insertBack(realString);
return;
}
// Should we use sceintific notation?
if ((decimalPoint <= -4) || (decimalPoint > cast(int) n))
{
if (precision > length)
{
precision = length - 1;
}
else if (precision > 0)
{
// When using scientific notation, there is one digit before the
// decimal.
--precision;
}
// Handle leading chars.
bufferSlice.front = realString[0];
bufferSlice.popFront();
if (precision != 0)
{
bufferSlice.front = period;
bufferSlice.popFront();
}
// Handle after decimal.
if ((length - 1) > precision)
{
length = precision + 1;
}
realString[1 .. length].copy(bufferSlice);
bufferSlice.popFrontExactly(length - 1);
// Dump the exponent.
tail[1] = 'e';
--decimalPoint;
if (decimalPoint < 0)
{
tail[2] = '-';
decimalPoint = -decimalPoint;
}
else
{
tail[2] = '+';
}
n = decimalPoint >= 100 ? 5 : 4;
tail[0] = cast(char) n;
while (true)
{
tail[n] = '0' + decimalPoint % 10;
if (n <= 3)
{
break;
}
--n;
decimalPoint /= 10;
}
}
else
{
if (decimalPoint > 0)
{
precision = decimalPoint < (cast(int) length)
? length - decimalPoint
: 0;
}
else
{
precision = -decimalPoint
+ (precision > length ? length : precision);
}
// Handle the three decimal varieties.
if (decimalPoint <= 0)
{
// Handle 0.000*000xxxx.
bufferSlice.front = '0';
bufferSlice.popFront();
if (precision != 0)
{
bufferSlice.front = period;
bufferSlice.popFront();
}
n = -decimalPoint;
if (n > precision)
{
n = precision;
}
fill!'0'(bufferSlice[0 .. n]);
bufferSlice.popFrontExactly(n);
if ((length + n) > precision)
{
length = precision - n;
}
realString[0 .. length].copy(bufferSlice);
bufferSlice.popFrontExactly(length);
}
else if (cast(uint) decimalPoint >= length)
{
// Handle xxxx000*000.0.
n = 0;
do
{
bufferSlice.front = realString[n];
bufferSlice.popFront();
++n;
}
while (n < length);
if (n < cast(uint) decimalPoint)
{
n = decimalPoint - n;
fill!'0'(bufferSlice[0 .. n]);
bufferSlice.popFrontExactly(n);
}
if (precision != 0)
{
bufferSlice.front = period;
bufferSlice.popFront();
}
}
else
{
// Handle xxxxx.xxxx000*000.
n = 0;
do
{
bufferSlice.front = realString[n];
bufferSlice.popFront();
++n;
}
while (n < cast(uint) decimalPoint);
if (precision > 0)
{
bufferSlice.front = period;
bufferSlice.popFront();
}
if ((length - decimalPoint) > precision)
{
length = precision + decimalPoint;
}
realString[n .. length].copy(bufferSlice);
bufferSlice.popFrontExactly(length - n);
}
}
// Get the length that we've copied.
length = cast(uint) (buffer.length - bufferSlice.length);
result.insertBack(buffer[64 .. length]); // Number.
result.insertBack(tail[1 .. tail[0] + 1]); // Tail.
}
private ref String printToString(string fmt, Args...)(return ref String result,
auto ref Args args)
{
@ -549,199 +745,7 @@ private ref String printToString(string fmt, Args...)(return ref String result,
}
else static if (isFloatingPoint!(Args[0])) // Float
{
char[512] buffer; // Big enough for e+308 or e-307.
char[8] tail = 0;
char[] bufferSlice = buffer[64 .. $];
uint precision = 6;
bool negative;
int decimalPoint;
// Read the double into a string.
auto realString = real2String(args[0], buffer, decimalPoint, negative);
auto length = cast(uint) realString.length;
// Clamp the precision and delete extra zeros after clamp.
uint n = precision;
if (length > precision)
{
length = precision;
}
while ((length > 1)
&& (precision != 0)
&& (realString[length - 1] == '0'))
{
--precision;
--length;
}
if (negative)
{
result.insertBack('-');
}
if (decimalPoint == special)
{
result.insertBack(realString);
goto ParamEnd;
}
// Should we use sceintific notation?
if ((decimalPoint <= -4) || (decimalPoint > cast(int) n))
{
if (precision > length)
{
precision = length - 1;
}
else if (precision > 0)
{
// When using scientific notation, there is one digit before the
// decimal.
--precision;
}
// Handle leading chars.
bufferSlice.front = realString[0];
bufferSlice.popFront();
if (precision != 0)
{
bufferSlice.front = period;
bufferSlice.popFront();
}
// Handle after decimal.
if ((length - 1) > precision)
{
length = precision + 1;
}
realString[1 .. length].copy(bufferSlice);
bufferSlice.popFrontExactly(length - 1);
// Dump the exponent.
tail[1] = 'e';
--decimalPoint;
if (decimalPoint < 0)
{
tail[2] = '-';
decimalPoint = -decimalPoint;
}
else
{
tail[2] = '+';
}
n = decimalPoint >= 100 ? 5 : 4;
tail[0] = cast(char) n;
while (true)
{
tail[n] = '0' + decimalPoint % 10;
if (n <= 3)
{
break;
}
--n;
decimalPoint /= 10;
}
}
else
{
if (decimalPoint > 0)
{
precision = decimalPoint < (cast(int) length)
? length - decimalPoint
: 0;
}
else
{
precision = -decimalPoint
+ (precision > length ? length : precision);
}
// Handle the three decimal varieties.
if (decimalPoint <= 0)
{
// Handle 0.000*000xxxx.
bufferSlice.front = '0';
bufferSlice.popFront();
if (precision != 0)
{
bufferSlice.front = period;
bufferSlice.popFront();
}
n = -decimalPoint;
if (n > precision)
{
n = precision;
}
fill!'0'(bufferSlice[0 .. n]);
bufferSlice.popFrontExactly(n);
if ((length + n) > precision)
{
length = precision - n;
}
realString[0 .. length].copy(bufferSlice);
bufferSlice.popFrontExactly(length);
}
else if (cast(uint) decimalPoint >= length)
{
// Handle xxxx000*000.0.
n = 0;
do
{
bufferSlice.front = realString[n];
bufferSlice.popFront();
++n;
}
while (n < length);
if (n < cast(uint) decimalPoint)
{
n = decimalPoint - n;
fill!'0'(bufferSlice[0 .. n]);
bufferSlice.popFrontExactly(n);
}
if (precision != 0)
{
bufferSlice.front = period;
bufferSlice.popFront();
}
}
else
{
// Handle xxxxx.xxxx000*000.
n = 0;
do
{
bufferSlice.front = realString[n];
bufferSlice.popFront();
++n;
}
while (n < cast(uint) decimalPoint);
if (precision > 0)
{
bufferSlice.front = period;
bufferSlice.popFront();
}
if ((length - decimalPoint) > precision)
{
length = precision + decimalPoint;
}
realString[n .. length].copy(bufferSlice);
bufferSlice.popFrontExactly(length - n);
}
}
// Get the length that we've copied.
length = cast(uint) (buffer.length - bufferSlice.length);
result.insertBack(buffer[64 .. length]); // Number.
result.insertBack(tail[1 .. tail[0] + 1]); // Tail.
formatReal(args[0], result);
}
else static if (isPointer!(Args[0])) // Pointer
{
@ -768,7 +772,6 @@ private ref String printToString(string fmt, Args...)(return ref String result,
{
result.insertBack(Args[0].stringof);
}
ParamEnd:
return result;
}