mirror of
https://github.com/fmtlib/fmt.git
synced 2024-12-24 03:17:53 +00:00
Support named arguments
This commit is contained in:
jamboree
parent
ed2dfe5124
commit
7487bde587
@ -72,6 +72,10 @@ Write API
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Utilities
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=========
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.. doxygenfunction:: fmt::arg(StringRef, const T&)
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.. doxygendefine:: FMT_CAPTURE
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.. doxygendefine:: FMT_VARIADIC
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.. doxygenclass:: fmt::ArgList
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@ -15,13 +15,15 @@ literal text, it can be escaped by doubling: ``{{`` and ``}}``.
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The grammar for a replacement field is as follows:
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.. productionlist:: sf
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replacement_field: "{" [`arg_index`] [":" `format_spec`] "}"
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replacement_field: "{" [`arg_field`] [":" `format_spec`] "}"
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arg_field: `arg_index` | `arg_name`
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arg_index: `integer`
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arg_name: \^[a-zA-Z_][a-zA-Z0-9_]*$\
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In less formal terms, the replacement field can start with an *arg_index*
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In less formal terms, the replacement field can start with an *arg_field*
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that specifies the argument whose value is to be formatted and inserted into
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the output instead of the replacement field.
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The *arg_index* is optionally followed by a *format_spec*, which is preceded
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The *arg_field* is optionally followed by a *format_spec*, which is preceded
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by a colon ``':'``. These specify a non-default format for the replacement value.
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See also the :ref:`formatspec` section.
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@ -73,8 +75,8 @@ The general form of a *standard format specifier* is:
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fill: <a character other than '{' or '}'>
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align: "<" | ">" | "=" | "^"
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sign: "+" | "-" | " "
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width: `integer` | "{" `arg_index` "}"
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precision: `integer` | "{" `arg_index` "}"
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width: `integer` | "{" `arg_field` "}"
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precision: `integer` | "{" `arg_field` "}"
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type: `int_type` | "c" | "e" | "E" | "f" | "F" | "g" | "G" | "p" | "s"
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int_type: "b" | "B" | "d" | "o" | "x" | "X"
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103
format.cc
103
format.cc
@ -265,6 +265,11 @@ int parse_nonnegative_int(const Char *&s) {
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return value;
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}
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template <typename Char>
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inline bool is_name_start(Char c) {
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return ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') || '_' == c;
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}
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inline void require_numeric_argument(const Arg &arg, char spec) {
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if (arg.type > Arg::LAST_NUMERIC_TYPE) {
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std::string message =
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@ -580,6 +585,49 @@ FMT_FUNC void fmt::internal::format_windows_error(
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}
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#endif
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template <typename Char>
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void fmt::ArgList::Map<Char>::init(const ArgList &args) {
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if (!map_.empty())
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return;
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const internal::NamedArg<Char>* named_arg;
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bool use_values = args.type(MAX_PACKED_ARGS - 1) == internal::Arg::NONE;
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if (use_values) {
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for (unsigned i = 0;/*nothing*/; ++i) {
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internal::Arg::Type arg_type = args.type(i);
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switch (arg_type) {
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case internal::Arg::NONE:
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return;
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case internal::Arg::NAMED_ARG:
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named_arg = static_cast<const internal::NamedArg<Char>*>(args.values_[i].pointer);
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map_.insert(Pair(named_arg->name, *named_arg));
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break;
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default:
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/*nothing*/;
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}
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}
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return;
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}
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for (unsigned i = 0; i != MAX_PACKED_ARGS; ++i) {
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internal::Arg::Type arg_type = args.type(i);
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if (arg_type == internal::Arg::NAMED_ARG) {
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named_arg = static_cast<const internal::NamedArg<Char>*>(args.args_[i].pointer);
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map_.insert(Pair(named_arg->name, *named_arg));
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}
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}
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for (unsigned i = MAX_PACKED_ARGS;/*nothing*/; ++i) {
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switch (args.args_[i].type) {
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case internal::Arg::NONE:
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return;
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case internal::Arg::NAMED_ARG:
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named_arg = static_cast<const internal::NamedArg<Char>*>(args.args_[i].pointer);
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map_.insert(Pair(named_arg->name, *named_arg));
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break;
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default:
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/*nothing*/;
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}
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}
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}
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// An argument formatter.
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template <typename Char>
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class fmt::internal::ArgFormatter :
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@ -681,6 +729,20 @@ void fmt::BasicWriter<Char>::write_str(
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write_str(str_value, str_size, spec);
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}
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template <typename Char>
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inline Arg fmt::BasicFormatter<Char>::get_arg(
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const BasicStringRef<Char>& arg_name, const char *&error) {
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if (check_no_auto_index(error)) {
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next_arg_index_ = -1;
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map_.init(args_);
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const Arg* arg = map_.find(arg_name);
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if (arg)
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return *arg;
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error = "argument not found";
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}
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return Arg();
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}
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template <typename Char>
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inline Arg fmt::BasicFormatter<Char>::parse_arg_index(const Char *&s) {
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const char *error = 0;
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@ -693,11 +755,33 @@ inline Arg fmt::BasicFormatter<Char>::parse_arg_index(const Char *&s) {
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return arg;
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}
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template <typename Char>
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inline Arg fmt::BasicFormatter<Char>::parse_arg_name(const Char *&s) {
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assert(is_name_start(*s));
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const Char *start = s;
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Char c;
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do {
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c = *++s;
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} while (('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') || ('0' <= c && c <= '9'));
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const char *error = 0;
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Arg arg = get_arg(fmt::BasicStringRef<Char>(start, s - start), error);
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if (error)
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FMT_THROW(fmt::FormatError(error));
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return arg;
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}
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FMT_FUNC Arg fmt::internal::FormatterBase::do_get_arg(
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unsigned arg_index, const char *&error) {
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Arg arg = args_[arg_index];
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if (arg.type == Arg::NONE)
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switch (arg.type) {
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case Arg::NONE:
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error = "argument index out of range";
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break;
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case Arg::NAMED_ARG:
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arg = *static_cast<const internal::Arg*>(arg.pointer);
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default:
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/*nothing*/;
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}
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return arg;
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}
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@ -708,13 +792,20 @@ inline Arg fmt::internal::FormatterBase::next_arg(const char *&error) {
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return Arg();
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}
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inline bool fmt::internal::FormatterBase::check_no_auto_index(const char *&error) {
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if (next_arg_index_ > 0) {
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error = "cannot switch from automatic to manual argument indexing";
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return false;
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}
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return true;
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}
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inline Arg fmt::internal::FormatterBase::get_arg(
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unsigned arg_index, const char *&error) {
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if (next_arg_index_ <= 0) {
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if (check_no_auto_index(error)) {
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next_arg_index_ = -1;
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return do_get_arg(arg_index, error);
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}
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error = "cannot switch from automatic to manual argument indexing";
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return Arg();
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}
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@ -1038,7 +1129,7 @@ const Char *fmt::BasicFormatter<Char>::format(
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spec.width_ = parse_nonnegative_int(s);
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} else if (*s == '{') {
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++s;
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const Arg &width_arg = parse_arg_index(s);
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const Arg &width_arg = is_name_start(*s) ? parse_arg_name(s) : parse_arg_index(s);
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if (*s++ != '}')
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FMT_THROW(FormatError("invalid format string"));
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ULongLong value = 0;
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@ -1075,7 +1166,7 @@ const Char *fmt::BasicFormatter<Char>::format(
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spec.precision_ = parse_nonnegative_int(s);
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} else if (*s == '{') {
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++s;
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const Arg &precision_arg = parse_arg_index(s);
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const Arg &precision_arg = is_name_start(*s) ? parse_arg_name(s) : parse_arg_index(s);
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if (*s++ != '}')
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FMT_THROW(FormatError("invalid format string"));
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ULongLong value = 0;
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@ -1142,7 +1233,7 @@ void fmt::BasicFormatter<Char>::format(
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if (c == '}')
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FMT_THROW(FormatError("unmatched '}' in format string"));
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write(writer_, start_, s - 1);
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Arg arg = parse_arg_index(s);
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Arg arg = is_name_start(*s) ? parse_arg_name(s) : parse_arg_index(s);
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s = format(s, arg);
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}
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write(writer_, start_, s);
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113
format.h
113
format.h
@ -39,6 +39,7 @@
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#include <stdexcept>
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#include <string>
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#include <sstream>
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#include <map>
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#if _SECURE_SCL
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# include <iterator>
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@ -163,10 +164,12 @@ inline uint32_t clzll(uint64_t x) {
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// This should be used in the private: declarations for a class
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#if FMT_USE_DELETED_FUNCTIONS || FMT_HAS_FEATURE(cxx_deleted_functions) || \
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(FMT_GCC_VERSION >= 404 && FMT_HAS_GXX_CXX11) || _MSC_VER >= 1800
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# define FMT_DELETED_OR_UNDEFINED = delete
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# define FMT_DISALLOW_COPY_AND_ASSIGN(TypeName) \
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TypeName(const TypeName&) = delete; \
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TypeName& operator=(const TypeName&) = delete
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#else
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# define FMT_DELETED_OR_UNDEFINED
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# define FMT_DISALLOW_COPY_AND_ASSIGN(TypeName) \
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TypeName(const TypeName&); \
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TypeName& operator=(const TypeName&)
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@ -274,6 +277,9 @@ class BasicStringRef {
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friend bool operator!=(BasicStringRef lhs, BasicStringRef rhs) {
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return lhs.data_ != rhs.data_;
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}
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friend bool operator<(BasicStringRef lhs, BasicStringRef rhs) {
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return std::lexicographical_compare(lhs.data_, lhs.data_ + lhs.size_, rhs.data_, rhs.data_ + rhs.size_);
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}
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};
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typedef BasicStringRef<char> StringRef;
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@ -752,7 +758,7 @@ struct Value {
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};
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enum Type {
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NONE,
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NONE, NAMED_ARG,
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// Integer types should go first,
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INT, UINT, LONG_LONG, ULONG_LONG, CHAR, LAST_INTEGER_TYPE = CHAR,
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// followed by floating-point types.
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@ -767,6 +773,9 @@ struct Arg : Value {
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Type type;
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};
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template <typename Char>
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struct NamedArg;
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template <typename T = void>
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struct None {};
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@ -962,6 +971,24 @@ class MakeValue : public Arg {
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static uint64_t type(const T &) {
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return IsConvertibleToInt<T>::value ? Arg::INT : Arg::CUSTOM;
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}
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// Additional template param `Char_` is needed here because make_type always uses MakeValue<char>.
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template <typename Char_>
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MakeValue(const NamedArg<Char_> &value) { pointer = &value; }
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template <typename Char_>
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static uint64_t type(const NamedArg<Char_> &) { return Arg::NAMED_ARG; }
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};
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template <typename Char>
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struct NamedArg : Arg {
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BasicStringRef<Char> name;
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template <typename T>
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NamedArg(BasicStringRef<Char> name, const T &value)
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: name(name), Arg(MakeValue<Char>(value)) {
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type = static_cast<internal::Arg::Type>(MakeValue<Char>::type(value));
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}
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};
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#define FMT_DISPATCH(call) static_cast<Impl*>(this)->call
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@ -1112,6 +1139,9 @@ class ArgList {
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// Maximum number of arguments with packed types.
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enum { MAX_PACKED_ARGS = 16 };
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template <typename Char>
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struct Map;
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ArgList() : types_(0) {}
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ArgList(ULongLong types, const internal::Value *values)
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@ -1146,12 +1176,31 @@ class ArgList {
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}
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};
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template <typename Char>
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struct fmt::ArgList::Map {
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typedef std::map<fmt::BasicStringRef<Char>, internal::Arg> MapType;
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typedef typename MapType::value_type Pair;
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void init(const ArgList &args);
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const internal::Arg* find(const fmt::BasicStringRef<Char> &name) const {
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typename MapType::const_iterator it = map_.find(name);
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if (it != map_.end())
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return &it->second;
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return 0;
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}
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private:
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MapType map_;
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};
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struct FormatSpec;
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namespace internal {
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class FormatterBase {
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private:
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protected:
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ArgList args_;
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int next_arg_index_;
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@ -1171,6 +1220,8 @@ class FormatterBase {
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// specified index.
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Arg get_arg(unsigned arg_index, const char *&error);
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bool check_no_auto_index(const char *&error);
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template <typename Char>
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void write(BasicWriter<Char> &w, const Char *start, const Char *end) {
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if (start != end)
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@ -1204,12 +1255,22 @@ class BasicFormatter : private internal::FormatterBase {
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private:
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BasicWriter<Char> &writer_;
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const Char *start_;
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ArgList::Map<Char> map_;
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FMT_DISALLOW_COPY_AND_ASSIGN(BasicFormatter);
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using FormatterBase::get_arg;
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// Checks if manual indexing is used and returns the argument with
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// specified name.
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internal::Arg get_arg(const BasicStringRef<Char>& arg_name, const char *&error);
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// Parses argument index and returns corresponding argument.
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internal::Arg parse_arg_index(const Char *&s);
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// Parses argument name and returns corresponding argument.
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internal::Arg parse_arg_name(const Char *&s);
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public:
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explicit BasicFormatter(BasicWriter<Char> &w) : writer_(w) {}
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@ -2675,6 +2736,32 @@ inline void format_decimal(char *&buffer, T value) {
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internal::format_decimal(buffer, abs_value, num_digits);
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buffer += num_digits;
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}
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/**
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\rst
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Returns a named argument for formatting functions.
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**Example**::
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print("Elapsed time: {s:.2f} seconds", arg("s", 1.23));
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\endrst
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*/
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template <typename T>
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inline internal::NamedArg<char> arg(StringRef name, const T &arg) {
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return internal::NamedArg<char>(name, arg);
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}
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template <typename T>
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inline internal::NamedArg<wchar_t> arg(WStringRef name, const T &arg) {
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return internal::NamedArg<wchar_t>(name, arg);
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}
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template <typename Char>
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void arg(StringRef name, const internal::NamedArg<Char>&) FMT_DELETED_OR_UNDEFINED;
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template <typename Char>
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void arg(WStringRef name, const internal::NamedArg<Char>&) FMT_DELETED_OR_UNDEFINED;
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}
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#if FMT_GCC_VERSION
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@ -2779,6 +2866,28 @@ inline void format_decimal(char *&buffer, T value) {
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#define FMT_VARIADIC_W(ReturnType, func, ...) \
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FMT_VARIADIC_(wchar_t, ReturnType, func, return func, __VA_ARGS__)
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#define FMT_CAPTURE_ARG_(id, index) ::fmt::arg(#id, id)
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#define FMT_CAPTURE_ARG_W_(id, index) ::fmt::arg(L###id, id)
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/**
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\rst
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Convenient macro to capture the arguments' names and values into several
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`fmt::arg(name, value)`.
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**Example**::
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int x = 1, y = 2;
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print("point: ({x}, {y})", FMT_CAPTURE(x, y));
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// same as:
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// print("point: ({x}, {y})", arg("x", x), arg("y", y));
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\endrst
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*/
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#define FMT_CAPTURE(...) FMT_FOR_EACH(FMT_CAPTURE_ARG_, __VA_ARGS__)
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#define FMT_CAPTURE_W(...) FMT_FOR_EACH(FMT_CAPTURE_ARG_W_, __VA_ARGS__)
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namespace fmt {
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FMT_VARIADIC(std::string, format, StringRef)
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FMT_VARIADIC_W(std::wstring, format, WStringRef)
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@ -562,7 +562,7 @@ TEST(FormatterTest, ArgsInDifferentPositions) {
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TEST(FormatterTest, ArgErrors) {
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EXPECT_THROW_MSG(format("{"), FormatError, "invalid format string");
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EXPECT_THROW_MSG(format("{x}"), FormatError, "invalid format string");
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EXPECT_THROW_MSG(format("{?}"), FormatError, "invalid format string");
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EXPECT_THROW_MSG(format("{0"), FormatError, "invalid format string");
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EXPECT_THROW_MSG(format("{0}"), FormatError, "argument index out of range");
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@ -609,6 +609,23 @@ TEST(FormatterTest, ManyArgs) {
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}
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#endif
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TEST(FormatterTest, NamedArg) {
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char a = 'A', b = 'B', c = 'C';
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EXPECT_EQ("BBAACC", format("{1}{b}{0}{a}{2}{c}", FMT_CAPTURE(a, b, c)));
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EXPECT_EQ(" A", format("{a:>2}", FMT_CAPTURE(a)));
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EXPECT_THROW_MSG(format("{a+}", FMT_CAPTURE(a)), FormatError, "missing '}' in format string");
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EXPECT_THROW_MSG(format("{a}"), FormatError, "argument not found");
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EXPECT_THROW_MSG(format("{d}", FMT_CAPTURE(a, b, c)), FormatError, "argument not found");
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EXPECT_THROW_MSG(format("{a}{}", FMT_CAPTURE(a)),
|
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FormatError, "cannot switch from manual to automatic argument indexing");
|
||||
EXPECT_THROW_MSG(format("{}{a}", FMT_CAPTURE(a)),
|
||||
FormatError, "cannot switch from automatic to manual argument indexing");
|
||||
EXPECT_EQ(" -42", format("{0:{width}}", -42, fmt::arg("width", 4)));
|
||||
EXPECT_EQ("st", format("{0:.{precision}}", "str", fmt::arg("precision", 2)));
|
||||
int n = 100;
|
||||
EXPECT_EQ(L"n=100", format(L"n={n}", FMT_CAPTURE_W(n)));
|
||||
}
|
||||
|
||||
TEST(FormatterTest, AutoArgIndex) {
|
||||
EXPECT_EQ("abc", format("{}{}{}", 'a', 'b', 'c'));
|
||||
EXPECT_THROW_MSG(format("{0}{}", 'a', 'b'),
|
||||
@ -920,7 +937,7 @@ TEST(FormatterTest, RuntimeWidth) {
|
||||
FormatError, "invalid format string");
|
||||
EXPECT_THROW_MSG(format("{0:{}", 0),
|
||||
FormatError, "cannot switch from manual to automatic argument indexing");
|
||||
EXPECT_THROW_MSG(format("{0:{x}}", 0),
|
||||
EXPECT_THROW_MSG(format("{0:{?}}", 0),
|
||||
FormatError, "invalid format string");
|
||||
EXPECT_THROW_MSG(format("{0:{1}}", 0),
|
||||
FormatError, "argument index out of range");
|
||||
@ -1037,7 +1054,7 @@ TEST(FormatterTest, RuntimePrecision) {
|
||||
FormatError, "invalid format string");
|
||||
EXPECT_THROW_MSG(format("{0:.{}", 0),
|
||||
FormatError, "cannot switch from manual to automatic argument indexing");
|
||||
EXPECT_THROW_MSG(format("{0:.{x}}", 0),
|
||||
EXPECT_THROW_MSG(format("{0:.{?}}", 0),
|
||||
FormatError, "invalid format string");
|
||||
EXPECT_THROW_MSG(format("{0:.{1}", 0, 0),
|
||||
FormatError, "precision not allowed in integer format specifier");
|
||||
|
||||
Loading…
Reference in New Issue
Block a user