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Commit a0d685c7 authored by Victor Zverovich's avatar Victor Zverovich
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Implement fill.

parent 30ab3491
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Showing with 126 additions and 79 deletions
format.cc
View file @ a0d685c7
......@@ -104,8 +104,8 @@ void Formatter::ReportError(const char *s, const std::string &message) const {
}
template <typename T>
void Formatter::FormatInt(T value, unsigned flags, int width, char type) {
int size = 0;
void Formatter::FormatInt(T value, const FormatSpec &spec) {
unsigned size = 0;
char sign = 0;
typedef typename IntTraits<T>::UnsignedType UnsignedType;
UnsignedType abs_value = value;
......@@ -113,20 +113,19 @@ void Formatter::FormatInt(T value, unsigned flags, int width, char type) {
sign = '-';
++size;
abs_value = -value;
} else if ((flags & PLUS_FLAG) != 0) {
} else if ((spec.flags & PLUS_FLAG) != 0) {
sign = '+';
++size;
}
char fill = (flags & ZERO_FLAG) != 0 ? '0' : ' ';
size_t start = buffer_.size();
char *p = 0;
switch (type) {
switch (spec.type) {
case 0: case 'd': {
UnsignedType n = abs_value;
do {
++size;
} while ((n /= 10) != 0);
width = std::max(width, size);
unsigned width = std::max(spec.width, size);
p = GrowBuffer(width) + width - 1;
n = abs_value;
do {
......@@ -136,20 +135,21 @@ void Formatter::FormatInt(T value, unsigned flags, int width, char type) {
}
case 'x': case 'X': {
UnsignedType n = abs_value;
bool print_prefix = (flags & HEX_PREFIX_FLAG) != 0;
bool print_prefix = (spec.flags & HEX_PREFIX_FLAG) != 0;
if (print_prefix) size += 2;
do {
++size;
} while ((n >>= 4) != 0);
width = std::max(width, size);
unsigned width = std::max(spec.width, size);
p = GrowBuffer(width) + width - 1;
n = abs_value;
const char *digits = type == 'x' ? "0123456789abcdef" : "0123456789ABCDEF";
const char *digits = spec.type == 'x' ?
"0123456789abcdef" : "0123456789ABCDEF";
do {
*p-- = digits[n & 0xf];
} while ((n >>= 4) != 0);
if (print_prefix) {
*p-- = type;
*p-- = spec.type;
*p-- = '0';
}
break;
......@@ -159,7 +159,7 @@ void Formatter::FormatInt(T value, unsigned flags, int width, char type) {
do {
++size;
} while ((n >>= 3) != 0);
width = std::max(width, size);
unsigned width = std::max(spec.width, size);
p = GrowBuffer(width) + width - 1;
n = abs_value;
do {
......@@ -168,22 +168,22 @@ void Formatter::FormatInt(T value, unsigned flags, int width, char type) {
break;
}
default:
ReportUnknownType(type, "integer");
ReportUnknownType(spec.type, "integer");
break;
}
if (sign) {
if ((flags & ZERO_FLAG) != 0)
if ((spec.flags & ZERO_FLAG) != 0)
buffer_[start++] = sign;
else
*p-- = sign;
}
std::fill(&buffer_[start], p + 1, fill);
std::fill(&buffer_[start], p + 1, spec.fill);
}
template <typename T>
void Formatter::FormatDouble(
T value, unsigned flags, int width, int precision, char type) {
void Formatter::FormatDouble(T value, const FormatSpec &spec, int precision) {
// Check type.
char type = spec.type;
switch (type) {
case 0:
type = 'g';
......@@ -205,12 +205,13 @@ void Formatter::FormatDouble(
enum { MAX_FORMAT_SIZE = 9}; // longest format: %+0*.*Lg
char format[MAX_FORMAT_SIZE];
char *format_ptr = format;
unsigned width = spec.width;
*format_ptr++ = '%';
if ((flags & PLUS_FLAG) != 0)
if ((spec.flags & PLUS_FLAG) != 0)
*format_ptr++ = '+';
if ((flags & ZERO_FLAG) != 0)
if ((spec.flags & ZERO_FLAG) != 0)
*format_ptr++ = '0';
if (width > 0)
if (width != 0)
*format_ptr++ = '*';
if (precision >= 0) {
*format_ptr++ = '.';
......@@ -226,16 +227,19 @@ void Formatter::FormatDouble(
for (;;) {
size_t size = buffer_.capacity() - offset;
int n = 0;
if (width <= 0) {
char *start = &buffer_[offset];
if (width == 0) {
n = precision < 0 ?
snprintf(&buffer_[offset], size, format, value) :
snprintf(&buffer_[offset], size, format, precision, value);
snprintf(start, size, format, value) :
snprintf(start, size, format, precision, value);
} else {
n = precision < 0 ?
snprintf(&buffer_[offset], size, format, width, value) :
snprintf(&buffer_[offset], size, format, width, precision, value);
snprintf(start, size, format, width, value) :
snprintf(start, size, format, width, precision, value);
}
if (n >= 0 && offset + n < buffer_.capacity()) {
while (*start == ' ')
*start++ = spec.fill;
GrowBuffer(n);
return;
}
......@@ -285,12 +289,21 @@ void Formatter::DoFormat() {
const Arg &arg = ParseArgIndex(s);
unsigned flags = 0;
int width = 0;
FormatSpec spec = {};
spec.fill = ' ';
int precision = -1;
char type = 0;
if (*s == ':') {
++s;
if (char c = *s) {
switch (s[1]) {
case '<': case '>': case '=': case '^':
if (c != '{' && c != '}') {
s += 2;
spec.fill = c;
}
break;
}
}
if (*s == '+') {
++s;
if (arg.type > LAST_NUMERIC_TYPE)
......@@ -299,13 +312,14 @@ void Formatter::DoFormat() {
ReportError(s,
"format specifier '+' requires signed argument");
}
flags |= PLUS_FLAG;
spec.flags |= PLUS_FLAG;
}
if (*s == '0') {
++s;
if (arg.type > LAST_NUMERIC_TYPE)
ReportError(s, "format specifier '0' requires numeric argument");
flags |= ZERO_FLAG;
spec.flags |= ZERO_FLAG;
spec.fill = '0';
}
// Parse width.
......@@ -313,7 +327,7 @@ void Formatter::DoFormat() {
unsigned value = ParseUInt(s);
if (value > INT_MAX)
ReportError(s, "number is too big in format");
width = value;
spec.width = value;
}
// Parse precision.
......@@ -367,7 +381,7 @@ void Formatter::DoFormat() {
// Parse type.
if (*s != '}' && *s)
type = *s++;
spec.type = *s++;
}
if (*s++ != '}')
......@@ -377,35 +391,35 @@ void Formatter::DoFormat() {
// Format argument.
switch (arg.type) {
case INT:
FormatInt(arg.int_value, flags, width, type);
FormatInt(arg.int_value, spec);
break;
case UINT:
FormatInt(arg.uint_value, flags, width, type);
FormatInt(arg.uint_value, spec);
break;
case LONG:
FormatInt(arg.long_value, flags, width, type);
FormatInt(arg.long_value, spec);
break;
case ULONG:
FormatInt(arg.ulong_value, flags, width, type);
FormatInt(arg.ulong_value, spec);
break;
case DOUBLE:
FormatDouble(arg.double_value, flags, width, precision, type);
FormatDouble(arg.double_value, spec, precision);
break;
case LONG_DOUBLE:
FormatDouble(arg.long_double_value, flags, width, precision, type);
FormatDouble(arg.long_double_value, spec, precision);
break;
case CHAR: {
if (type && type != 'c')
ReportUnknownType(type, "char");
char *out = GrowBuffer(std::max(width, 1));
if (spec.type && spec.type != 'c')
ReportUnknownType(spec.type, "char");
char *out = GrowBuffer(std::max(spec.width, 1u));
*out++ = arg.int_value;
if (width > 1)
std::fill_n(out, width - 1, ' ');
if (spec.width > 1)
std::fill_n(out, spec.width - 1, spec.fill);
break;
}
case STRING: {
if (type && type != 's')
ReportUnknownType(type, "string");
if (spec.type && spec.type != 's')
ReportUnknownType(spec.type, "string");
const char *str = arg.string.value;
size_t size = arg.string.size;
if (size == 0) {
......@@ -414,22 +428,23 @@ void Formatter::DoFormat() {
if (*str)
size = std::strlen(str);
}
char *out = GrowBuffer(std::max<size_t>(width, size));
char *out = GrowBuffer(std::max<size_t>(spec.width, size));
out = std::copy(str, str + size, out);
if (static_cast<unsigned>(width) > size)
std::fill_n(out, width - size, ' ');
if (spec.width > size)
std::fill_n(out, spec.width - size, spec.fill);
break;
}
case POINTER:
if (type && type != 'p')
ReportUnknownType(type, "pointer");
FormatInt(reinterpret_cast<uintptr_t>(
arg.pointer_value), HEX_PREFIX_FLAG, width, 'x');
if (spec.type && spec.type != 'p')
ReportUnknownType(spec.type, "pointer");
spec.flags = HEX_PREFIX_FLAG;
spec.type = 'x';
FormatInt(reinterpret_cast<uintptr_t>(arg.pointer_value), spec);
break;
case CUSTOM:
if (type)
ReportUnknownType(type, "object");
(this->*arg.custom.format)(arg.custom.value, width);
if (spec.type)
ReportUnknownType(spec.type, "object");
(this->*arg.custom.format)(arg.custom.value, spec);
break;
default:
assert(false);
......@@ -440,9 +455,9 @@ void Formatter::DoFormat() {
buffer_.resize(buffer_.size() - 1); // Don't count the terminating zero.
}
void Formatter::Write(const std::string &s, unsigned width) {
char *out = GrowBuffer(std::max<std::size_t>(width, s.size()));
void Formatter::Write(const std::string &s, const FormatSpec &spec) {
char *out = GrowBuffer(std::max<std::size_t>(spec.width, s.size()));
std::copy(s.begin(), s.end(), out);
if (width > s.size())
std::fill_n(out + s.size(), width - s.size(), ' ');
if (spec.width > s.size())
std::fill_n(out + s.size(), spec.width - s.size(), spec.fill);
}
format.h
View file @ a0d685c7
......@@ -123,6 +123,13 @@ class FormatError : public std::runtime_error {
: std::runtime_error(message) {}
};
struct FormatSpec {
unsigned flags;
unsigned width;
char type;
char fill;
};
// Formatter provides string formatting functionality similar to Python's
// str.format. The output is stored in a memory buffer that grows dynamically.
// Usage:
......@@ -149,7 +156,8 @@ class Formatter {
CHAR, STRING, WSTRING, POINTER, CUSTOM
};
typedef void (Formatter::*FormatFunc)(const void *arg, unsigned width);
typedef void (Formatter::*FormatFunc)(
const void *arg, const FormatSpec &spec);
// A format argument.
class Arg {
......@@ -258,16 +266,15 @@ class Formatter {
// Formats an integer.
template <typename T>
void FormatInt(T value, unsigned flags, int width, char type);
void FormatInt(T value, const FormatSpec &spec);
// Formats a floating point number (double or long double).
template <typename T>
void FormatDouble(
T value, unsigned flags, int width, int precision, char type);
void FormatDouble(T value, const FormatSpec &spec, int precision);
// Formats an argument of a custom type, such as a user-defined class.
template <typename T>
void FormatCustomArg(const void *arg, unsigned width);
void FormatCustomArg(const void *arg, const FormatSpec &spec);
unsigned ParseUInt(const char *&s) const;
......@@ -306,7 +313,7 @@ class Formatter {
// Writes a string to the output buffer padding with spaces if
// necessary to achieve the desired width.
void Write(const std::string &s, unsigned width);
void Write(const std::string &s, const FormatSpec &spec);
};
// A reference to a string. It can be constructed from a C string,
......@@ -443,23 +450,23 @@ class ArgFormatter {
public:
explicit ArgFormatter(Formatter &f) : formatter_(f) {}
void Write(const std::string &s, unsigned width) {
formatter_.Write(s, width);
void Write(const std::string &s, const FormatSpec &spec) {
formatter_.Write(s, spec);
}
};
// The default formatting function.
template <typename T>
void Format(ArgFormatter &af, unsigned width, const T &value) {
void Format(ArgFormatter &af, const FormatSpec &spec, const T &value) {
std::ostringstream os;
os << value;
af.Write(os.str(), width);
af.Write(os.str(), spec);
}
template <typename T>
void Formatter::FormatCustomArg(const void *arg, unsigned width) {
void Formatter::FormatCustomArg(const void *arg, const FormatSpec &spec) {
ArgFormatter af(*this);
Format(af, width, *static_cast<const T*>(arg));
Format(af, spec, *static_cast<const T*>(arg));
}
inline internal::ArgInserter Formatter::operator()(const char *format) {
......
format_test.cc
View file @ a0d685c7
......@@ -257,6 +257,21 @@ TEST(FormatterTest, EmptySpecs) {
EXPECT_EQ("42", str(Format("{0:}") << 42));
}
TEST(FormatterTest, Fill) {
EXPECT_EQ("**42", str(Format("{0:*>4}") << 42));
EXPECT_EQ("**-42", str(Format("{0:*>5}") << -42));
EXPECT_EQ("***42", str(Format("{0:*>5}") << 42u));
EXPECT_EQ("**-42", str(Format("{0:*>5}") << -42l));
EXPECT_EQ("***42", str(Format("{0:*>5}") << 42ul));
EXPECT_EQ("**-42", str(Format("{0:*>5}") << -42.0));
EXPECT_EQ("**-42", str(Format("{0:*>5}") << -42.0l));
EXPECT_EQ("c****", str(Format("{0:*<5}") << 'c'));
EXPECT_EQ("abc**", str(Format("{0:*<5}") << "abc"));
EXPECT_EQ("**0xface", str(Format("{0:*>8}")
<< reinterpret_cast<void*>(0xface)));
EXPECT_EQ("def**", str(Format("{0:*<5}") << TestString("def")));
}
TEST(FormatterTest, PlusFlag) {
EXPECT_EQ("+42", str(Format("{0:+}") << 42));
EXPECT_EQ("-42", str(Format("{0:+}") << -42));
......@@ -484,7 +499,7 @@ void CheckUnknownTypes(
for (int i = CHAR_MIN; i <= CHAR_MAX; ++i) {
char c = i;
if (std::strchr(types, c) || std::strchr(special, c) || !c) continue;
sprintf(format, "{0:1%c}", c);
sprintf(format, "{0:10%c}", c);
if (std::isprint(static_cast<unsigned char>(c)))
sprintf(message, "unknown format code '%c' for %s", c, type_name);
else
......@@ -629,22 +644,32 @@ TEST(FormatterTest, FormatString) {
TEST(FormatterTest, Write) {
Formatter format;
format.Write("12", 2);
fmt::FormatSpec spec = {};
spec.fill = ' ';
spec.width = 2;
format.Write("12", spec);
EXPECT_EQ("12", format.str());
format.Write("34", 4);
spec.width = 4;
format.Write("34", spec);
EXPECT_EQ("1234 ", format.str());
format.Write("56", 0);
spec.width = 0;
format.Write("56", spec);
EXPECT_EQ("1234 56", format.str());
}
TEST(ArgFormatterTest, Write) {
Formatter formatter;
fmt::ArgFormatter format(formatter);
format.Write("12", 2);
fmt::FormatSpec spec = {};
spec.fill = ' ';
spec.width = 2;
format.Write("12", spec);
EXPECT_EQ("12", formatter.str());
format.Write("34", 4);
spec.width = 4;
format.Write("34", spec);
EXPECT_EQ("1234 ", formatter.str());
format.Write("56", 0);
spec.width = 0;
format.Write("56", spec);
EXPECT_EQ("1234 56", formatter.str());
}
......@@ -669,8 +694,8 @@ TEST(FormatterTest, FormatUsingIOStreams) {
class Answer {};
void Format(fmt::ArgFormatter &af, unsigned width, Answer) {
af.Write("42", width);
void Format(fmt::ArgFormatter &af, const fmt::FormatSpec &spec, Answer) {
af.Write("42", spec);
}
TEST(FormatterTest, CustomFormat) {
......
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