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#pragma once
#include "format_string.h"
#include "string_builder.h"
#include <util/generic/string.h>
namespace NYT {
////////////////////////////////////////////////////////////////////////////////
/*
* Format: a type-safe and fast formatting utility.
*
* Basically works as a type-safe analogue of |sprintf| and is expected to
* be backwards-compatible with the latter.
*
* Like Go's |Sprintf|, supports the ultimate format specifier |v|
* causing arguments to be emitted in default format.
* This is the default and preferred way of formatting things,
* which should be used in newer code.
*
* |Format| may currently invoke |sprintf| internally for emitting numeric and some other
* types. You can always write your own optimized implementation, if you wish :)
*
* In additional to the usual |sprintf|, supports a number of non-standard flags:
*
* |q| Causes the argument to be surrounded with single quotes (|'|).
* Applies to all types.
*
* |Q| Causes the argument to be surrounded with double quotes (|"|).
* Applies to all types.
*
* |l| The argument is emitted in "lowercase" style.
* Only applies to enums and bools.
*
* The following argument types are supported:
*
* Strings (including |const char*|, |TStringBuf|, and |TString|) and chars:
* Emitted as is. Fast.
*
* Numerics and pointers:
* Emitted using |sprintf|. Maybe not that fast.
*
* |bool|:
* Emitted either as |True| and |False| or |true| and |false| (if lowercase mode is ON).
*
* Enums:
* Emitted in either camel (|SomeName|) or in lowercase-with-underscores style
* (|some_name|, if lowercase mode is ON).
*
* Nullables:
* |std::nullopt| is emitted as |<null>|.
*
* All others:
* Emitted as strings by calling |ToString|.
*
*/
template <class... TArgs>
TString Format(TFormatString<TArgs...> format, TArgs&&... args);
////////////////////////////////////////////////////////////////////////////////
template <class... TArgs>
void Format(TStringBuilderBase* builder, TFormatString<TArgs...> format, TArgs&&... args);
////////////////////////////////////////////////////////////////////////////////
template <class T>
TString ToStringViaBuilder(const T& value, TStringBuf spec = TStringBuf("v"));
////////////////////////////////////////////////////////////////////////////////
template <class TRange, class TFormatter>
struct TFormattableView
{
using TBegin = std::decay_t<decltype(std::declval<const TRange>().begin())>;
using TEnd = std::decay_t<decltype(std::declval<const TRange>().end())>;
TBegin RangeBegin;
TEnd RangeEnd;
TFormatter Formatter;
size_t Limit = std::numeric_limits<size_t>::max();
TBegin begin() const;
TEnd end() const;
};
//! Annotates a given #range with #formatter to be applied to each item.
template <class TRange, class TFormatter>
TFormattableView<TRange, TFormatter> MakeFormattableView(
const TRange& range,
TFormatter&& formatter);
template <class TRange, class TFormatter>
TFormattableView<TRange, TFormatter> MakeShrunkFormattableView(
const TRange& range,
TFormatter&& formatter,
size_t limit);
////////////////////////////////////////////////////////////////////////////////
template <class TFormatter>
struct TFormatterWrapper
{
TFormatter Formatter;
};
// Allows insertion of text conditionally.
// Usage:
/*
NYT::Format(
"Value is %v%v",
42,
MakeFormatterWrapper([&] (auto* builder) {
if (PossiblyMissingInfo_) {
builder->AppendString(", PossiblyMissingInfo: ");
FormatValue(builder, PossiblyMissingInfo_, "v");
}
}));
*/
template <class TFormatter>
TFormatterWrapper<TFormatter> MakeFormatterWrapper(
TFormatter&& formatter);
////////////////////////////////////////////////////////////////////////////////
template <class... TArgs>
class TLazyMultiValueFormatter;
template <class... TArgs>
void FormatValue(
TStringBuilderBase* builder,
const TLazyMultiValueFormatter<TArgs...>& value,
TStringBuf /*spec*/);
//! A wrapper for a bunch of values that formats them lazily on demand.
/*!
* The intended use of this class is when you need to use the same formatted string
* in several places in the function (e.g. log message tags) and want both to avoid
* code duplication and premature formatting of the values until necessary.
*
* NB: lvalues are captured by reference without lifetime extension.
*/
template <class... TArgs>
class TLazyMultiValueFormatter
: private TNonCopyable
{
public:
TLazyMultiValueFormatter(TStringBuf format, TArgs&&... args);
// NB(arkady-e1ppa): We actually have to
// forward declare this method as above
// and friend-declare it as specialization
// here because clang is stupid and would
// treat this friend declartion as a hidden friend
// declaration which in turn is treated as a separate symbol
// causing linker to not find the actual definition.
friend void FormatValue<>(
TStringBuilderBase* builder,
const TLazyMultiValueFormatter& value,
TStringBuf /*spec*/);
private:
const TStringBuf Format_;
const std::tuple<TArgs...> Args_;
};
template <class ... Args>
auto MakeLazyMultiValueFormatter(TStringBuf format, Args&&... args);
////////////////////////////////////////////////////////////////////////////////
/*
Example:
FormatVector("One: %v, Two: %v, Three: %v", {1, 2, 3})
=> "One: 1, Two: 2, Three: 3"
*/
template <size_t Length, class TVector>
void FormatVector(
TStringBuilderBase* builder,
const char (&format)[Length],
const TVector& vec);
template <class TVector>
void FormatVector(
TStringBuilderBase* builder,
TStringBuf format,
const TVector& vec);
template <size_t Length, class TVector>
TString FormatVector(
const char (&format)[Length],
const TVector& vec);
template <class TVector>
TString FormatVector(
TStringBuf format,
const TVector& vec);
////////////////////////////////////////////////////////////////////////////////
} // namespace NYT
#define FORMAT_INL_H_
#include "format-inl.h"
#undef FORMAT_INL_H_
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