/*
- * Copyright 2013 Facebook, Inc.
+ * Copyright 2016 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* limitations under the License.
*/
-#ifndef FOLLY_FORMAT_H_
+#pragma once
#define FOLLY_FORMAT_H_
-#include <array>
#include <cstdio>
#include <tuple>
#include <type_traits>
-#include <vector>
-#include <deque>
-#include <map>
-#include <unordered_map>
-
-#include <double-conversion.h>
-
-#include "folly/FBVector.h"
-#include "folly/Conv.h"
-#include "folly/Range.h"
-#include "folly/Traits.h"
-#include "folly/Likely.h"
-#include "folly/String.h"
-#include "folly/small_vector.h"
-#include "folly/FormatArg.h"
+
+#include <folly/Conv.h>
+#include <folly/Range.h>
+#include <folly/Traits.h>
+#include <folly/String.h>
+#include <folly/FormatArg.h>
// Ignore shadowing warnings within this file, so includers can use -Wshadow.
#pragma GCC diagnostic push
Formatter<true, C> vformat(StringPiece fmt, C&& container);
template <class T, class Enable=void> class FormatValue;
+// meta-attribute to identify formatters in this sea of template weirdness
+namespace detail {
+class FormatterTag {};
+};
+
/**
* Formatter class.
*
* this directly, you have to use format(...) below.
*/
-template <bool containerMode, class... Args>
-class Formatter {
- template <class... A>
- friend Formatter<false, A...> format(StringPiece fmt, A&&... arg);
- template <class C>
- friend Formatter<true, C> vformat(StringPiece fmt, C&& container);
+/* BaseFormatter class. Currently, the only behavior that can be
+ * overridden is the actual formatting of positional parameters in
+ * `doFormatArg`. The Formatter class provides the default implementation.
+ */
+template <class Derived, bool containerMode, class... Args>
+class BaseFormatter {
public:
/**
* Append to output. out(StringPiece sp) may be called (more than once)
* Append to a string.
*/
template <class Str>
- typename std::enable_if<detail::IsSomeString<Str>::value>::type
+ typename std::enable_if<IsSomeString<Str>::value>::type
appendTo(Str& str) const {
auto appender = [&str] (StringPiece s) { str.append(s.data(), s.size()); };
(*this)(appender);
return s;
}
- private:
- explicit Formatter(StringPiece str, Args&&... args);
-
- // Not copyable
- Formatter(const Formatter&) = delete;
- Formatter& operator=(const Formatter&) = delete;
-
- // Movable, but the move constructor and assignment operator are private,
- // for the exclusive use of format() (below). This way, you can't create
- // a Formatter object, but can handle references to it (for streaming,
- // conversion to string, etc) -- which is good, as Formatter objects are
- // dangerous (they hold references, possibly to temporaries)
- Formatter(Formatter&&) = default;
- Formatter& operator=(Formatter&&) = default;
+ /**
+ * metadata to identify generated children of BaseFormatter
+ */
+ typedef detail::FormatterTag IsFormatter;
+ typedef BaseFormatter BaseType;
+ private:
typedef std::tuple<FormatValue<
typename std::decay<Args>::type>...> ValueTuple;
static constexpr size_t valueCount = std::tuple_size<ValueTuple>::value;
template <size_t K, class Callback>
typename std::enable_if<K == valueCount>::type
- doFormatFrom(size_t i, FormatArg& arg, Callback& cb) const {
- LOG(FATAL) << arg.errorStr("argument index out of range, max=", i);
+ doFormatFrom(size_t i, FormatArg& arg, Callback& /*cb*/) const {
+ arg.error("argument index out of range, max=", i);
}
template <size_t K, class Callback>
typename std::enable_if<(K < valueCount)>::type
doFormatFrom(size_t i, FormatArg& arg, Callback& cb) const {
if (i == K) {
- std::get<K>(values_).format(arg, cb);
+ static_cast<const Derived*>(this)->template doFormatArg<K>(arg, cb);
} else {
doFormatFrom<K+1>(i, arg, cb);
}
return doFormatFrom<0>(i, arg, cb);
}
+ template <size_t K>
+ typename std::enable_if<K == valueCount, int>::type
+ getSizeArgFrom(size_t i, const FormatArg& arg) const {
+ arg.error("argument index out of range, max=", i);
+ }
+
+ template <class T>
+ typename std::enable_if<std::is_integral<T>::value &&
+ !std::is_same<T, bool>::value, int>::type
+ getValue(const FormatValue<T>& format, const FormatArg&) const {
+ return static_cast<int>(format.getValue());
+ }
+
+ template <class T>
+ typename std::enable_if<!std::is_integral<T>::value ||
+ std::is_same<T, bool>::value, int>::type
+ getValue(const FormatValue<T>&, const FormatArg& arg) const {
+ arg.error("dynamic field width argument must be integral");
+ }
+
+ template <size_t K>
+ typename std::enable_if<K < valueCount, int>::type
+ getSizeArgFrom(size_t i, const FormatArg& arg) const {
+ if (i == K) {
+ return getValue(std::get<K>(values_), arg);
+ }
+ return getSizeArgFrom<K+1>(i, arg);
+ }
+
+ int getSizeArg(size_t i, const FormatArg& arg) const {
+ return getSizeArgFrom<0>(i, arg);
+ }
+
StringPiece str_;
+
+ protected:
+ explicit BaseFormatter(StringPiece str, Args&&... args);
+
+ // Not copyable
+ BaseFormatter(const BaseFormatter&) = delete;
+ BaseFormatter& operator=(const BaseFormatter&) = delete;
+
+ // Movable, but the move constructor and assignment operator are private,
+ // for the exclusive use of format() (below). This way, you can't create
+ // a Formatter object, but can handle references to it (for streaming,
+ // conversion to string, etc) -- which is good, as Formatter objects are
+ // dangerous (they hold references, possibly to temporaries)
+ BaseFormatter(BaseFormatter&&) = default;
+ BaseFormatter& operator=(BaseFormatter&&) = default;
+
ValueTuple values_;
};
+template <bool containerMode, class... Args>
+class Formatter : public BaseFormatter<Formatter<containerMode, Args...>,
+ containerMode,
+ Args...> {
+ private:
+ explicit Formatter(StringPiece& str, Args&&... args)
+ : BaseFormatter<Formatter<containerMode, Args...>,
+ containerMode,
+ Args...>(str, std::forward<Args>(args)...) {}
+
+ template <size_t K, class Callback>
+ void doFormatArg(FormatArg& arg, Callback& cb) const {
+ std::get<K>(this->values_).format(arg, cb);
+ }
+
+ friend class BaseFormatter<Formatter<containerMode, Args...>,
+ containerMode,
+ Args...>;
+
+ template <class... A>
+ friend Formatter<false, A...> format(StringPiece fmt, A&&... arg);
+ template <class C>
+ friend Formatter<true, C> vformat(StringPiece fmt, C&& container);
+};
+
/**
* Formatter objects can be written to streams.
*/
/**
* Formatter objects can be written to stdio FILEs.
*/
-template<bool containerMode, class... Args>
-void writeTo(FILE* fp, const Formatter<containerMode, Args...>& formatter);
+template <class Derived, bool containerMode, class... Args>
+void writeTo(FILE* fp,
+ const BaseFormatter<Derived, containerMode, Args...>& formatter);
/**
* Create a formatter object.
fmt, std::forward<Args>(args)...);
}
+/**
+ * Like format(), but immediately returns the formatted string instead of an
+ * intermediate format object.
+ */
+template <class... Args>
+inline std::string sformat(StringPiece fmt, Args&&... args) {
+ return format(fmt, std::forward<Args>(args)...).str();
+}
+
/**
* Create a formatter object that takes one argument (of container type)
* and uses that container to get argument values from.
fmt, std::forward<Container>(container));
}
+/**
+ * Like vformat(), but immediately returns the formatted string instead of an
+ * intermediate format object.
+ */
+template <class Container>
+inline std::string svformat(StringPiece fmt, Container&& container) {
+ return vformat(fmt, std::forward<Container>(container)).str();
+}
+
+/**
+ * Wrap a sequence or associative container so that out-of-range lookups
+ * return a default value rather than throwing an exception.
+ *
+ * Usage:
+ * format("[no_such_key"], defaulted(map, 42)) -> 42
+ */
+namespace detail {
+template <class Container, class Value> struct DefaultValueWrapper {
+ DefaultValueWrapper(const Container& container, const Value& defaultValue)
+ : container(container),
+ defaultValue(defaultValue) {
+ }
+
+ const Container& container;
+ const Value& defaultValue;
+};
+} // namespace
+
+template <class Container, class Value>
+detail::DefaultValueWrapper<Container, Value>
+defaulted(const Container& c, const Value& v) {
+ return detail::DefaultValueWrapper<Container, Value>(c, v);
+}
+
/**
* Append formatted output to a string.
*
* Shortcut for toAppend(format(...), &foo);
*/
template <class Str, class... Args>
-typename std::enable_if<detail::IsSomeString<Str>::value>::type
+typename std::enable_if<IsSomeString<Str>::value>::type
format(Str* out, StringPiece fmt, Args&&... args) {
format(fmt, std::forward<Args>(args)...).appendTo(*out);
}
* Append vformatted output to a string.
*/
template <class Str, class Container>
-typename std::enable_if<detail::IsSomeString<Str>::value>::type
+typename std::enable_if<IsSomeString<Str>::value>::type
vformat(Str* out, StringPiece fmt, Container&& container) {
vformat(fmt, std::forward<Container>(container)).appendTo(*out);
}
* formatString(fmt.str(), arg, cb); but avoids creating a temporary
* string if possible.
*/
-template <class FormatCallback, bool containerMode, class... Args>
-void formatFormatter(const Formatter<containerMode, Args...>& formatter,
- FormatArg& arg,
- FormatCallback& cb);
+template <class FormatCallback,
+ class Derived,
+ bool containerMode,
+ class... Args>
+void formatFormatter(
+ const BaseFormatter<Derived, containerMode, Args...>& formatter,
+ FormatArg& arg,
+ FormatCallback& cb);
} // namespace format_value
* empty string)
*/
+namespace detail {
+
+template <class T, class Enable = void>
+struct IsFormatter : public std::false_type {};
+
+template <class T>
+struct IsFormatter<
+ T,
+ typename std::enable_if<
+ std::is_same<typename T::IsFormatter, detail::FormatterTag>::value>::
+ type> : public std::true_type {};
+} // folly::detail
+
+// Deprecated API. formatChecked() et. al. now behave identically to their
+// non-Checked counterparts.
+template <class... Args>
+Formatter<false, Args...> formatChecked(StringPiece fmt, Args&&... args) {
+ return format(fmt, std::forward<Args>(args)...);
+}
+template <class... Args>
+inline std::string sformatChecked(StringPiece fmt, Args&&... args) {
+ return formatChecked(fmt, std::forward<Args>(args)...).str();
+}
+template <class Container>
+Formatter<true, Container> vformatChecked(StringPiece fmt,
+ Container&& container) {
+ return vformat(fmt, std::forward<Container>(container));
+}
+template <class Container>
+inline std::string svformatChecked(StringPiece fmt, Container&& container) {
+ return vformatChecked(fmt, std::forward<Container>(container)).str();
+}
+template <class Str, class... Args>
+typename std::enable_if<IsSomeString<Str>::value>::type
+formatChecked(Str* out, StringPiece fmt, Args&&... args) {
+ formatChecked(fmt, std::forward<Args>(args)...).appendTo(*out);
+}
+template <class Str, class Container>
+typename std::enable_if<IsSomeString<Str>::value>::type
+vformatChecked(Str* out, StringPiece fmt, Container&& container) {
+ vformatChecked(fmt, std::forward<Container>(container)).appendTo(*out);
+}
+
} // namespace folly
-#include "folly/Format-inl.h"
+#include <folly/Format-inl.h>
#pragma GCC diagnostic pop
-
-#endif /* FOLLY_FORMAT_H_ */
projects / folly.git / blobdiff