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asl/asl/formatting/format.hpp

115 lines
2.4 KiB
C++

// Copyright 2025 Steven Le Rouzic
//
// SPDX-License-Identifier: BSD-3-Clause
#pragma once
#include "asl/base/integers.hpp"
#include "asl/base/float.hpp"
#include "asl/base/meta.hpp"
#include "asl/io/writer.hpp"
#include "asl/types/span.hpp"
#include "asl/strings/string_view.hpp"
namespace asl
{
class Formatter;
template<typename T>
concept formattable = requires (Formatter& f, const T& value)
{
AslFormat(f, value);
};
namespace format_internals
{
struct type_erased_arg
{
const void* data;
void (*fn)(Formatter&, const void*);
template<formattable T>
static constexpr void erased_fn(Formatter& f, const void* data)
{
AslFormat(f, *static_cast<const T*>(data));
}
template<formattable T>
explicit constexpr type_erased_arg(const T& arg)
: data{&arg}
, fn{erased_fn<T>}
{}
};
void format(Writer*, string_view fmt, span<const type_erased_arg> args);
} // namespace format_internals
class Formatter
{
Writer* m_writer;
public:
explicit constexpr Formatter(Writer* writer)
: m_writer{writer}
{}
constexpr void write(string_view s)
{
m_writer->write(as_bytes(s.as_span()));
}
[[nodiscard]] constexpr Writer* writer() const { return m_writer; }
};
template<formattable... Args>
void format(Writer* w, string_view fmt, const Args&... args)
{
if constexpr (types_count<Args...> > 0)
{
const format_internals::type_erased_arg type_erased_args[] = {
format_internals::type_erased_arg(args)...
};
format_internals::format(w, fmt, type_erased_args);
}
else
{
format_internals::format(w, fmt, {});
}
}
template<isize_t N>
void AslFormat(Formatter& f, const char (&str)[N])
{
f.write(string_view(str, N - 1));
}
void AslFormat(Formatter& f, const char* str);
inline void AslFormat(Formatter& f, string_view sv)
{
f.write(sv);
}
void AslFormat(Formatter& f, float32_t);
void AslFormat(Formatter& f, float64_t);
void AslFormat(Formatter& f, bool);
void AslFormat(Formatter& f, uint8_t);
void AslFormat(Formatter& f, uint16_t);
void AslFormat(Formatter& f, uint32_t);
void AslFormat(Formatter& f, uint64_t);
void AslFormat(Formatter& f, int8_t);
void AslFormat(Formatter& f, int16_t);
void AslFormat(Formatter& f, int32_t);
void AslFormat(Formatter& f, int64_t);
string_view format_uint64(uint64_t value, span<char, 20> buffer);
} // namespace asl