519 lines
17 KiB
C++
519 lines
17 KiB
C++
// Formatting library for C++ - experimental format string compilation
|
|
//
|
|
// Copyright (c) 2012 - present, Victor Zverovich and fmt contributors
|
|
// All rights reserved.
|
|
//
|
|
// For the license information refer to format.h.
|
|
|
|
#ifndef FMT_COMPILE_H_
|
|
#define FMT_COMPILE_H_
|
|
|
|
#include <vector>
|
|
#include "format.h"
|
|
|
|
FMT_BEGIN_NAMESPACE
|
|
namespace internal {
|
|
|
|
// Part of a compiled format string. It can be either literal text or a
|
|
// replacement field.
|
|
template <typename Char> struct format_part {
|
|
enum class kind { arg_index, arg_name, text, replacement };
|
|
|
|
struct replacement {
|
|
arg_ref<Char> arg_id;
|
|
dynamic_format_specs<Char> specs;
|
|
};
|
|
|
|
kind part_kind;
|
|
union value {
|
|
unsigned arg_index;
|
|
basic_string_view<Char> str;
|
|
replacement repl;
|
|
|
|
FMT_CONSTEXPR value(unsigned index = 0) : arg_index(index) {}
|
|
FMT_CONSTEXPR value(basic_string_view<Char> s) : str(s) {}
|
|
FMT_CONSTEXPR value(replacement r) : repl(r) {}
|
|
} val;
|
|
// Position past the end of the argument id.
|
|
const Char* arg_id_end = nullptr;
|
|
|
|
FMT_CONSTEXPR format_part(kind k = kind::arg_index, value v = {})
|
|
: part_kind(k), val(v) {}
|
|
|
|
static FMT_CONSTEXPR format_part make_arg_index(unsigned index) {
|
|
return format_part(kind::arg_index, index);
|
|
}
|
|
static FMT_CONSTEXPR format_part make_arg_name(basic_string_view<Char> name) {
|
|
return format_part(kind::arg_name, name);
|
|
}
|
|
static FMT_CONSTEXPR format_part make_text(basic_string_view<Char> text) {
|
|
return format_part(kind::text, text);
|
|
}
|
|
static FMT_CONSTEXPR format_part make_replacement(replacement repl) {
|
|
return format_part(kind::replacement, repl);
|
|
}
|
|
};
|
|
|
|
template <typename Char> struct part_counter {
|
|
unsigned num_parts = 0;
|
|
|
|
FMT_CONSTEXPR void on_text(const Char* begin, const Char* end) {
|
|
if (begin != end) ++num_parts;
|
|
}
|
|
|
|
FMT_CONSTEXPR void on_arg_id() { ++num_parts; }
|
|
FMT_CONSTEXPR void on_arg_id(unsigned) { ++num_parts; }
|
|
FMT_CONSTEXPR void on_arg_id(basic_string_view<Char>) { ++num_parts; }
|
|
|
|
FMT_CONSTEXPR void on_replacement_field(const Char*) {}
|
|
|
|
FMT_CONSTEXPR const Char* on_format_specs(const Char* begin,
|
|
const Char* end) {
|
|
// Find the matching brace.
|
|
unsigned brace_counter = 0;
|
|
for (; begin != end; ++begin) {
|
|
if (*begin == '{') {
|
|
++brace_counter;
|
|
} else if (*begin == '}') {
|
|
if (brace_counter == 0u) break;
|
|
--brace_counter;
|
|
}
|
|
}
|
|
return begin;
|
|
}
|
|
|
|
FMT_CONSTEXPR void on_error(const char*) {}
|
|
};
|
|
|
|
// Counts the number of parts in a format string.
|
|
template <typename Char>
|
|
FMT_CONSTEXPR unsigned count_parts(basic_string_view<Char> format_str) {
|
|
part_counter<Char> counter;
|
|
parse_format_string<true>(format_str, counter);
|
|
return counter.num_parts;
|
|
}
|
|
|
|
template <typename Char, typename PartHandler>
|
|
class format_string_compiler : public error_handler {
|
|
private:
|
|
using part = format_part<Char>;
|
|
|
|
PartHandler handler_;
|
|
part part_;
|
|
basic_string_view<Char> format_str_;
|
|
basic_parse_context<Char> parse_context_;
|
|
|
|
public:
|
|
FMT_CONSTEXPR format_string_compiler(basic_string_view<Char> format_str,
|
|
PartHandler handler)
|
|
: handler_(handler),
|
|
format_str_(format_str),
|
|
parse_context_(format_str) {}
|
|
|
|
FMT_CONSTEXPR void on_text(const Char* begin, const Char* end) {
|
|
if (begin != end)
|
|
handler_(part::make_text({begin, to_unsigned(end - begin)}));
|
|
}
|
|
|
|
FMT_CONSTEXPR void on_arg_id() {
|
|
part_ = part::make_arg_index(parse_context_.next_arg_id());
|
|
}
|
|
|
|
FMT_CONSTEXPR void on_arg_id(unsigned id) {
|
|
parse_context_.check_arg_id(id);
|
|
part_ = part::make_arg_index(id);
|
|
}
|
|
|
|
FMT_CONSTEXPR void on_arg_id(basic_string_view<Char> id) {
|
|
part_ = part::make_arg_name(id);
|
|
}
|
|
|
|
FMT_CONSTEXPR void on_replacement_field(const Char* ptr) {
|
|
part_.arg_id_end = ptr;
|
|
handler_(part_);
|
|
}
|
|
|
|
FMT_CONSTEXPR const Char* on_format_specs(const Char* begin,
|
|
const Char* end) {
|
|
auto repl = typename part::replacement();
|
|
dynamic_specs_handler<basic_parse_context<Char>> handler(repl.specs,
|
|
parse_context_);
|
|
auto it = parse_format_specs(begin, end, handler);
|
|
if (*it != '}') on_error("missing '}' in format string");
|
|
repl.arg_id = part_.part_kind == part::kind::arg_index
|
|
? arg_ref<Char>(part_.val.arg_index)
|
|
: arg_ref<Char>(part_.val.str);
|
|
auto part = part::make_replacement(repl);
|
|
part.arg_id_end = begin;
|
|
handler_(part);
|
|
return it;
|
|
}
|
|
};
|
|
|
|
// Compiles a format string and invokes handler(part) for each parsed part.
|
|
template <bool IS_CONSTEXPR, typename Char, typename PartHandler>
|
|
FMT_CONSTEXPR void compile_format_string(basic_string_view<Char> format_str,
|
|
PartHandler handler) {
|
|
parse_format_string<IS_CONSTEXPR>(
|
|
format_str,
|
|
format_string_compiler<Char, PartHandler>(format_str, handler));
|
|
}
|
|
|
|
template <typename Range, typename Context, typename Id>
|
|
void format_arg(basic_parse_context<typename Range::value_type>& parse_ctx,
|
|
Context& ctx, Id arg_id) {
|
|
ctx.advance_to(
|
|
visit_format_arg(arg_formatter<Range>(ctx, &parse_ctx), ctx.arg(arg_id)));
|
|
}
|
|
|
|
// vformat_to is defined in a subnamespace to prevent ADL.
|
|
namespace cf {
|
|
template <typename Context, typename Range, typename CompiledFormat>
|
|
auto vformat_to(Range out, CompiledFormat& cf, basic_format_args<Context> args)
|
|
-> typename Context::iterator {
|
|
using char_type = typename Context::char_type;
|
|
basic_parse_context<char_type> parse_ctx(to_string_view(cf.format_str_));
|
|
Context ctx(out.begin(), args);
|
|
|
|
const auto& parts = cf.parts();
|
|
for (auto part_it = std::begin(parts); part_it != std::end(parts);
|
|
++part_it) {
|
|
const auto& part = *part_it;
|
|
const auto& value = part.val;
|
|
|
|
using format_part_t = format_part<char_type>;
|
|
switch (part.part_kind) {
|
|
case format_part_t::kind::text: {
|
|
const auto text = value.str;
|
|
auto output = ctx.out();
|
|
auto&& it = reserve(output, text.size());
|
|
it = std::copy_n(text.begin(), text.size(), it);
|
|
ctx.advance_to(output);
|
|
break;
|
|
}
|
|
|
|
case format_part_t::kind::arg_index:
|
|
advance_to(parse_ctx, part.arg_id_end);
|
|
internal::format_arg<Range>(parse_ctx, ctx, value.arg_index);
|
|
break;
|
|
|
|
case format_part_t::kind::arg_name:
|
|
advance_to(parse_ctx, part.arg_id_end);
|
|
internal::format_arg<Range>(parse_ctx, ctx, value.str);
|
|
break;
|
|
|
|
case format_part_t::kind::replacement: {
|
|
const auto& arg_id_value = value.repl.arg_id.val;
|
|
const auto arg = value.repl.arg_id.kind == arg_id_kind::index
|
|
? ctx.arg(arg_id_value.index)
|
|
: ctx.arg(arg_id_value.name);
|
|
|
|
auto specs = value.repl.specs;
|
|
|
|
handle_dynamic_spec<width_checker>(specs.width, specs.width_ref, ctx);
|
|
handle_dynamic_spec<precision_checker>(specs.precision,
|
|
specs.precision_ref, ctx);
|
|
|
|
error_handler h;
|
|
numeric_specs_checker<error_handler> checker(h, arg.type());
|
|
if (specs.align == align::numeric) checker.require_numeric_argument();
|
|
if (specs.sign != sign::none) checker.check_sign();
|
|
if (specs.alt) checker.require_numeric_argument();
|
|
if (specs.precision >= 0) checker.check_precision();
|
|
|
|
advance_to(parse_ctx, part.arg_id_end);
|
|
ctx.advance_to(
|
|
visit_format_arg(arg_formatter<Range>(ctx, nullptr, &specs), arg));
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
return ctx.out();
|
|
}
|
|
} // namespace cf
|
|
|
|
template <typename S, typename = void> struct compiled_format_base {
|
|
using char_type = char_t<S>;
|
|
using parts_container = std::vector<internal::format_part<char_type>>;
|
|
|
|
parts_container compiled_parts;
|
|
|
|
explicit compiled_format_base(basic_string_view<char_type> format_str) {
|
|
compile_format_string<false>(format_str,
|
|
[this](const format_part<char_type>& part) {
|
|
compiled_parts.push_back(part);
|
|
});
|
|
}
|
|
|
|
const parts_container& parts() const { return compiled_parts; }
|
|
};
|
|
|
|
template <typename Char, unsigned N> struct format_part_array {
|
|
format_part<Char> data[N] = {};
|
|
FMT_CONSTEXPR format_part_array() = default;
|
|
};
|
|
|
|
template <typename Char, unsigned N>
|
|
FMT_CONSTEXPR format_part_array<Char, N> compile_to_parts(
|
|
basic_string_view<Char> format_str) {
|
|
format_part_array<Char, N> parts;
|
|
unsigned counter = 0;
|
|
// This is not a lambda for compatibility with older compilers.
|
|
struct {
|
|
format_part<Char>* parts;
|
|
unsigned* counter;
|
|
FMT_CONSTEXPR void operator()(const format_part<Char>& part) {
|
|
parts[(*counter)++] = part;
|
|
}
|
|
} collector{parts.data, &counter};
|
|
compile_format_string<true>(format_str, collector);
|
|
if (counter < N) {
|
|
parts.data[counter] =
|
|
format_part<Char>::make_text(basic_string_view<Char>());
|
|
}
|
|
return parts;
|
|
}
|
|
|
|
template <typename T> constexpr const T& constexpr_max(const T& a, const T& b) {
|
|
return (a < b) ? b : a;
|
|
}
|
|
|
|
template <typename S>
|
|
struct compiled_format_base<S, enable_if_t<is_compile_string<S>::value>> {
|
|
using char_type = char_t<S>;
|
|
|
|
FMT_CONSTEXPR explicit compiled_format_base(basic_string_view<char_type>) {}
|
|
|
|
// Workaround for old compilers. Format string compilation will not be
|
|
// performed there anyway.
|
|
#if FMT_USE_CONSTEXPR
|
|
static FMT_CONSTEXPR_DECL const unsigned num_format_parts =
|
|
constexpr_max(count_parts(to_string_view(S())), 1u);
|
|
#else
|
|
static const unsigned num_format_parts = 1;
|
|
#endif
|
|
|
|
using parts_container = format_part<char_type>[num_format_parts];
|
|
|
|
const parts_container& parts() const {
|
|
static FMT_CONSTEXPR_DECL const auto compiled_parts =
|
|
compile_to_parts<char_type, num_format_parts>(
|
|
internal::to_string_view(S()));
|
|
return compiled_parts.data;
|
|
}
|
|
};
|
|
|
|
template <typename S, typename... Args>
|
|
class compiled_format : private compiled_format_base<S> {
|
|
public:
|
|
using typename compiled_format_base<S>::char_type;
|
|
|
|
private:
|
|
basic_string_view<char_type> format_str_;
|
|
|
|
template <typename Context, typename Range, typename CompiledFormat>
|
|
friend auto cf::vformat_to(Range out, CompiledFormat& cf,
|
|
basic_format_args<Context> args) ->
|
|
typename Context::iterator;
|
|
|
|
public:
|
|
compiled_format() = delete;
|
|
explicit constexpr compiled_format(basic_string_view<char_type> format_str)
|
|
: compiled_format_base<S>(format_str), format_str_(format_str) {}
|
|
};
|
|
|
|
#ifdef __cpp_if_constexpr
|
|
template <typename... Args> struct type_list {};
|
|
|
|
// Returns a reference to the argument at index N from [first, rest...].
|
|
template <int N, typename T, typename... Args>
|
|
const auto& get(const T& first, const Args&... rest) {
|
|
if constexpr (sizeof...(Args) == 0)
|
|
return first;
|
|
else
|
|
return get(rest...);
|
|
}
|
|
|
|
template <int N, typename> struct get_type_impl;
|
|
|
|
template <int N, typename... Args> struct get_type_impl<N, type_list<Args...>> {
|
|
using type = remove_cvref_t<decltype(get<N>(std::declval<Args>()...))>;
|
|
};
|
|
|
|
template <int N, typename T>
|
|
using get_type = typename get_type_impl<N, T>::type;
|
|
|
|
template <typename Char> struct text {
|
|
basic_string_view<Char> data;
|
|
|
|
template <typename OutputIt, typename... Args>
|
|
OutputIt format(OutputIt out, const Args&...) {
|
|
// TODO: reserve
|
|
return copy_str<Char>(data.begin(), data.end(), out);
|
|
}
|
|
};
|
|
|
|
template <typename Char>
|
|
constexpr text<Char> make_text(basic_string_view<Char> s, size_t pos,
|
|
size_t size) {
|
|
return {{&s[pos], size}};
|
|
}
|
|
|
|
template <typename Char, typename OutputIt, typename T,
|
|
std::enable_if_t<std::is_integral_v<T>, int> = 0>
|
|
OutputIt format_default(OutputIt out, T value) {
|
|
// TODO: reserve
|
|
format_int fi(value);
|
|
return std::copy(fi.data(), fi.data() + fi.size(), out);
|
|
}
|
|
|
|
template <typename Char, typename OutputIt>
|
|
OutputIt format_default(OutputIt out, Char value) {
|
|
*out++ = value;
|
|
return out;
|
|
}
|
|
|
|
template <typename Char, typename OutputIt>
|
|
OutputIt format_default(OutputIt out, const Char* value) {
|
|
auto length = std::char_traits<Char>::length(value);
|
|
return copy_str<Char>(value, value + length, out);
|
|
}
|
|
|
|
// A replacement field that refers to argument N.
|
|
template <typename Char, typename T, int N> struct field {
|
|
template <typename OutputIt, typename... Args>
|
|
OutputIt format(OutputIt out, const Args&... args) {
|
|
// This ensures that the argument type is convertile to `const T&`.
|
|
const T& arg = get<N>(args...);
|
|
return format_default<Char>(out, arg);
|
|
}
|
|
};
|
|
|
|
template <typename L, typename R> struct concat {
|
|
L lhs;
|
|
R rhs;
|
|
|
|
template <typename OutputIt, typename... Args>
|
|
OutputIt format(OutputIt out, const Args&... args) {
|
|
out = lhs.format(out, args...);
|
|
return rhs.format(out, args...);
|
|
}
|
|
};
|
|
|
|
template <typename L, typename R>
|
|
constexpr concat<L, R> make_concat(L lhs, R rhs) {
|
|
return {lhs, rhs};
|
|
}
|
|
|
|
template <typename Char>
|
|
constexpr size_t parse_text(basic_string_view<Char> str, size_t pos) {
|
|
for (size_t size = str.size(); pos != size; ++pos) {
|
|
if (str[pos] == '{' || str[pos] == '}') break;
|
|
}
|
|
return pos;
|
|
}
|
|
|
|
template <typename Args, size_t POS, int ID, typename S>
|
|
constexpr auto compile_format_string(S format_str);
|
|
|
|
template <typename Args, size_t POS, int ID, typename T, typename S>
|
|
auto parse_tail(T head, S format_str) {
|
|
if constexpr (POS != to_string_view(format_str).size())
|
|
return make_concat(head, compile_format_string<Args, POS, ID>(format_str));
|
|
else
|
|
return head;
|
|
}
|
|
|
|
template <typename Args, size_t POS, int ID, typename S>
|
|
constexpr auto compile_format_string(S format_str) {
|
|
using char_type = char_t<S>;
|
|
constexpr basic_string_view<char_type> str = format_str;
|
|
if constexpr (str.size() == 0) {
|
|
return make_text(str, 0, 0);
|
|
} else if constexpr (str[POS] == '{') {
|
|
if (POS + 1 == str.size())
|
|
throw format_error("unmatched '{' in format string");
|
|
if constexpr (str[POS + 1] == '{') {
|
|
return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
|
|
} else if constexpr (str[POS + 1] == '}') {
|
|
return parse_tail<Args, POS + 2, ID + 1>(
|
|
field<char_type, get_type<ID, Args>, ID>(), format_str);
|
|
} else {
|
|
throw format_error("invalid format string");
|
|
}
|
|
} else if constexpr (str[POS] == '}') {
|
|
if (POS + 1 == str.size())
|
|
throw format_error("unmatched '}' in format string");
|
|
return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
|
|
} else {
|
|
constexpr auto end = parse_text(str, POS + 1);
|
|
return parse_tail<Args, end, ID>(make_text(str, POS, end - POS),
|
|
format_str);
|
|
}
|
|
}
|
|
template <typename... Args, typename S> constexpr auto compile(S format_str) {
|
|
return compile_format_string<type_list<Args...>, 0, 0>(format_str);
|
|
}
|
|
#endif // __cpp_if_constexpr
|
|
} // namespace internal
|
|
|
|
#if FMT_USE_CONSTEXPR
|
|
template <typename... Args, typename S,
|
|
FMT_ENABLE_IF(is_compile_string<S>::value)>
|
|
FMT_CONSTEXPR auto compile(S format_str)
|
|
-> internal::compiled_format<S, Args...> {
|
|
return internal::compiled_format<S, Args...>(to_string_view(format_str));
|
|
}
|
|
#endif
|
|
|
|
// Compiles the format string which must be a string literal.
|
|
template <typename... Args, typename Char, size_t N>
|
|
auto compile(const Char (&format_str)[N])
|
|
-> internal::compiled_format<const Char*, Args...> {
|
|
return internal::compiled_format<const Char*, Args...>(
|
|
basic_string_view<Char>(format_str, N - 1));
|
|
}
|
|
|
|
template <typename CompiledFormat, typename... Args,
|
|
typename Char = typename CompiledFormat::char_type>
|
|
std::basic_string<Char> format(const CompiledFormat& cf, const Args&... args) {
|
|
basic_memory_buffer<Char> buffer;
|
|
using range = buffer_range<Char>;
|
|
using context = buffer_context<Char>;
|
|
internal::cf::vformat_to<context>(range(buffer), cf,
|
|
{make_format_args<context>(args...)});
|
|
return to_string(buffer);
|
|
}
|
|
|
|
template <typename OutputIt, typename CompiledFormat, typename... Args>
|
|
OutputIt format_to(OutputIt out, const CompiledFormat& cf,
|
|
const Args&... args) {
|
|
using char_type = typename CompiledFormat::char_type;
|
|
using range = internal::output_range<OutputIt, char_type>;
|
|
using context = format_context_t<OutputIt, char_type>;
|
|
return internal::cf::vformat_to<context>(
|
|
range(out), cf, {make_format_args<context>(args...)});
|
|
}
|
|
|
|
template <typename OutputIt, typename CompiledFormat, typename... Args,
|
|
FMT_ENABLE_IF(internal::is_output_iterator<OutputIt>::value)>
|
|
format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n,
|
|
const CompiledFormat& cf,
|
|
const Args&... args) {
|
|
auto it =
|
|
format_to(internal::truncating_iterator<OutputIt>(out, n), cf, args...);
|
|
return {it.base(), it.count()};
|
|
}
|
|
|
|
template <typename CompiledFormat, typename... Args>
|
|
std::size_t formatted_size(const CompiledFormat& cf, const Args&... args) {
|
|
return format_to(
|
|
internal::counting_iterator<typename CompiledFormat::char_type>(),
|
|
cf, args...)
|
|
.count();
|
|
}
|
|
|
|
FMT_END_NAMESPACE
|
|
|
|
#endif // FMT_COMPILE_H_
|