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Clean up after making formating floating point numbers @nogc.

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berni44 2021-04-24 14:08:50 +02:00 • committed by The Dlang Bot
parent afc2df6ef2
commit 3206e52aae
4 changed files with 976 additions and 1023 deletions
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8
changelog/formatting_floats_nogc.dd Normal file
View file

@ -0,0 +1,8 @@
Floating point numbers don't allocate with the GC anymore.
The implementation of formatting floating point numbers has been
reworked. We made sure that working examples never allocate with the
GC, however, we are still using exceptions which are GC managed.
Therefore, code that uses formatting correctly will never allocate,
but in the case of exceptions, the GC will be used to allocate the
exception. We are working on DIP 1008 to solve this issue.

1847
std/format/internal/floats.d
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File diff suppressed because it is too large Load diff

142
std/format/internal/write.d
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@ -506,9 +506,7 @@ if (is(FloatingPointTypeOf!T) && !is(T == enum) && !hasToString!(T, Char))
}
fs.spec = spec2;
buf = printFloat(buf2[], w, val, fs, mode);
len = buf.length;
if (len == 0) return;
printFloat(w, val, fs, mode);
}
else
{
@ -561,87 +559,87 @@ if (is(FloatingPointTypeOf!T) && !is(T == enum) && !hasToString!(T, Char))
len = min(n, buf2.length-1);
buf = buf2;
}
if (fs.flSeparator && !inf && !nan)
{
ptrdiff_t indexOfRemovable()
if (fs.flSeparator && !inf && !nan)
{
if (len < 2)
return -1;
size_t start = (buf[0 .. 1].indexOfAny(" 0123456789") == -1) ? 1 : 0;
if (len < 2 + start)
return -1;
if ((buf[start] == ' ') || (buf[start] == '0' && buf[start + 1] != '.'))
return start;
return -1;
}
ptrdiff_t dot, firstDigit, ePos, dotIdx, firstLen;
size_t separatorScoreCnt;
while (true)
{
dot = buf[0 .. len].indexOf('.');
firstDigit = buf[0 .. len].indexOfAny("0123456789");
ePos = buf[0 .. len].indexOf('e');
dotIdx = dot == -1 ? ePos == -1 ? len : ePos : dot;
firstLen = dotIdx - firstDigit;
separatorScoreCnt = (firstLen > 0) ? (firstLen - 1) / fs.separators : 0;
ptrdiff_t removableIdx = (len + separatorScoreCnt > fs.width) ? indexOfRemovable() : -1;
if ((removableIdx != -1) &&
((firstLen - (buf[removableIdx] == '0' ? 2 : 1)) / fs.separators + len - 1 >= fs.width))
ptrdiff_t indexOfRemovable()
{
buf[removableIdx .. $ - 1] = buf.dup[removableIdx + 1 .. $];
len--;
if (len < 2)
return -1;
size_t start = (buf[0 .. 1].indexOfAny(" 0123456789") == -1) ? 1 : 0;
if (len < 2 + start)
return -1;
if ((buf[start] == ' ') || (buf[start] == '0' && buf[start + 1] != '.'))
return start;
return -1;
}
else
break;
}
immutable afterDotIdx = (ePos != -1) ? ePos : len;
ptrdiff_t dot, firstDigit, ePos, dotIdx, firstLen;
size_t separatorScoreCnt;
// plus, minus, prefix
if (firstDigit > 0)
{
put(w, buf[0 .. firstDigit]);
}
// digits until dot with separator
for (auto j = 0; j < firstLen; ++j)
{
if (j > 0 && (firstLen - j) % fs.separators == 0)
while (true)
{
put(w, fs.separatorChar);
dot = buf[0 .. len].indexOf('.');
firstDigit = buf[0 .. len].indexOfAny("0123456789");
ePos = buf[0 .. len].indexOf('e');
dotIdx = dot == -1 ? ePos == -1 ? len : ePos : dot;
firstLen = dotIdx - firstDigit;
separatorScoreCnt = (firstLen > 0) ? (firstLen - 1) / fs.separators : 0;
ptrdiff_t removableIdx = (len + separatorScoreCnt > fs.width) ? indexOfRemovable() : -1;
if ((removableIdx != -1) &&
((firstLen - (buf[removableIdx] == '0' ? 2 : 1)) / fs.separators + len - 1 >= fs.width))
{
buf[removableIdx .. $ - 1] = buf.dup[removableIdx + 1 .. $];
len--;
}
else
break;
}
put(w, buf[j + firstDigit]);
}
// print dot for decimal numbers only or with '#' format specifier
if (dot != -1 || fs.flHash)
{
put(w, '.');
}
immutable afterDotIdx = (ePos != -1) ? ePos : len;
// digits after dot
for (auto j = dotIdx + 1; j < afterDotIdx; ++j)
{
put(w, buf[j]);
}
// plus, minus, prefix
if (firstDigit > 0)
{
put(w, buf[0 .. firstDigit]);
}
// rest
if (ePos != -1)
{
put(w, buf[afterDotIdx .. len]);
// digits until dot with separator
for (auto j = 0; j < firstLen; ++j)
{
if (j > 0 && (firstLen - j) % fs.separators == 0)
{
put(w, fs.separatorChar);
}
put(w, buf[j + firstDigit]);
}
// print dot for decimal numbers only or with '#' format specifier
if (dot != -1 || fs.flHash)
{
put(w, '.');
}
// digits after dot
for (auto j = dotIdx + 1; j < afterDotIdx; ++j)
{
put(w, buf[j]);
}
// rest
if (ePos != -1)
{
put(w, buf[afterDotIdx .. len]);
}
}
else
{
put(w, buf[0 .. len]);
}
}
else
{
put(w, buf[0 .. len]);
}
}

2
std/format/package.d
View file

@ -1511,8 +1511,6 @@ Note:
$(UL
$(LI An exception is thrown.)
$(LI A floating point number of type `real` is formatted.)
$(LI The representation of a floating point number exceeds 500 characters.)
$(LI A custom `toString` function of a compound type allocates.))
*/
char[] sformat(Char, Args...)(return scope char[] buf, scope const(Char)[] fmt, Args args)