X-Git-Url: http://plrg.eecs.uci.edu/git/?p=folly.git;a=blobdiff_plain;f=folly%2FString.h;h=ef153bd20b69f30f15afa89b91ac6d0f37f161c3;hp=563f5313ecc04a63c4fb739763a819a93026c1c6;hb=20808864dfde991fd740e6caefe632d4bf244d69;hpb=db66e2f4b93dee8c8834dede216e068a3a3e40af

diff --git a/folly/String.h b/folly/String.h
index 563f5313..ef153bd2 100644
--- a/folly/String.h
+++ b/folly/String.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 Facebook, Inc.
+ * Copyright 2011-present Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,30 +14,27 @@
  * limitations under the License.
  */
 
-#ifndef FOLLY_BASE_STRING_H_
-#define FOLLY_BASE_STRING_H_
+#pragma once
+#define FOLLY_STRING_H_
 
+#include <cstdarg>
 #include <exception>
 #include <string>
-#include <boost/type_traits.hpp>
-
-#ifdef FOLLY_HAVE_DEPRECATED_ASSOC
-#ifdef _GLIBCXX_SYMVER
-#include <ext/hash_set>
-#include <ext/hash_map>
-#endif
-#endif
-
-#include <unordered_set>
 #include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+#include <boost/regex/pending/unicode_iterator.hpp>
+#include <boost/type_traits.hpp>
 
 #include <folly/Conv.h>
-#include <folly/Demangle.h>
+#include <folly/ExceptionString.h>
 #include <folly/FBString.h>
 #include <folly/FBVector.h>
 #include <folly/Portability.h>
 #include <folly/Range.h>
 #include <folly/ScopeGuard.h>
+#include <folly/Traits.h>
 
 // Compatibility function, to make sure toStdString(s) can be called
 // to convert a std::string or fbstring variable s into type std::string
@@ -186,6 +183,16 @@ std::string& stringAppendf(std::string* output,
                           FOLLY_PRINTF_FORMAT const char* format, ...)
   FOLLY_PRINTF_FORMAT_ATTR(2, 3);
 
+/**
+ * Similar to stringPrintf, but accepts a va_list argument.
+ *
+ * As with vsnprintf() itself, the value of ap is undefined after the call.
+ * These functions do not call va_end() on ap.
+ */
+std::string stringVPrintf(const char* format, va_list ap);
+void stringVPrintf(std::string* out, const char* format, va_list ap);
+std::string& stringVAppendf(std::string* out, const char* format, va_list ap);
+
 /**
  * Backslashify a string, that is, replace non-printable characters
  * with C-style (but NOT C compliant) "\xHH" encoding.  If hex_style
@@ -205,12 +212,15 @@ std::string& stringAppendf(std::string* output,
  * C++, use cEscape instead.  This function is for display purposes
  * only.
  */
-template <class String1, class String2>
-void backslashify(const String1& input, String2& output, bool hex_style=false);
-
-template <class String>
-String backslashify(const String& input, bool hex_style=false) {
-  String output;
+template <class OutputString>
+void backslashify(
+    folly::StringPiece input,
+    OutputString& output,
+    bool hex_style = false);
+
+template <class OutputString = std::string>
+OutputString backslashify(StringPiece input, bool hex_style = false) {
+  OutputString output;
   backslashify(input, output, hex_style);
   return output;
 }
@@ -243,17 +253,43 @@ String humanify(const String& input) {
  * If append_output is true, append data to the output rather than
  * replace it.
  */
-template<class InputString, class OutputString>
+template <class InputString, class OutputString>
 bool hexlify(const InputString& input, OutputString& output,
              bool append=false);
 
+template <class OutputString = std::string>
+OutputString hexlify(ByteRange input) {
+  OutputString output;
+  if (!hexlify(input, output)) {
+    // hexlify() currently always returns true, so this can't really happen
+    throw std::runtime_error("hexlify failed");
+  }
+  return output;
+}
+
+template <class OutputString = std::string>
+OutputString hexlify(StringPiece input) {
+  return hexlify<OutputString>(ByteRange{input});
+}
+
 /**
  * Same functionality as Python's binascii.unhexlify.  Returns true
  * on successful conversion.
  */
-template<class InputString, class OutputString>
+template <class InputString, class OutputString>
 bool unhexlify(const InputString& input, OutputString& output);
 
+template <class OutputString = std::string>
+OutputString unhexlify(StringPiece input) {
+  OutputString output;
+  if (!unhexlify(input, output)) {
+    // unhexlify() fails if the input has non-hexidecimal characters,
+    // or if it doesn't consist of a whole number of bytes
+    throw std::domain_error("unhexlify() called with non-hex input");
+  }
+  return output;
+}
+
 /*
  * A pretty-printer for numbers that appends suffixes of units of the
  * given type.  It prints 4 sig-figs of value with the most
@@ -348,23 +384,6 @@ std::string hexDump(const void* ptr, size_t size);
  */
 fbstring errnoStr(int err);
 
-/**
- * Debug string for an exception: include type and what().
- */
-inline fbstring exceptionStr(const std::exception& e) {
-  return folly::to<fbstring>(demangle(typeid(e)), ": ", e.what());
-}
-
-inline fbstring exceptionStr(std::exception_ptr ep) {
-  try {
-    std::rethrow_exception(ep);
-  } catch (const std::exception& e) {
-    return exceptionStr(e);
-  } catch (...) {
-    return "<unknown exception>";
-  }
-}
-
 /*
  * Split a string into a list of tokens by delimiter.
  *
@@ -394,30 +413,35 @@ inline fbstring exceptionStr(std::exception_ptr ep) {
  * or not (generating empty tokens).
  */
 
-template<class Delim, class String, class OutputType>
+template <class Delim, class String, class OutputType>
 void split(const Delim& delimiter,
            const String& input,
            std::vector<OutputType>& out,
-           bool ignoreEmpty = false);
+           const bool ignoreEmpty = false);
 
-template<class Delim, class String, class OutputType>
+template <class Delim, class String, class OutputType>
 void split(const Delim& delimiter,
            const String& input,
            folly::fbvector<OutputType>& out,
-           bool ignoreEmpty = false);
+           const bool ignoreEmpty = false);
 
-template<class OutputValueType, class Delim, class String,
-         class OutputIterator>
+template <
+    class OutputValueType,
+    class Delim,
+    class String,
+    class OutputIterator>
 void splitTo(const Delim& delimiter,
              const String& input,
              OutputIterator out,
-             bool ignoreEmpty = false);
+             const bool ignoreEmpty = false);
 
 /*
  * Split a string into a fixed number of string pieces and/or numeric types
- * by delimiter. Any numeric type that folly::to<> can convert to from a
- * string piece is supported as a target. Returns 'true' if the fields were
- * all successfully populated.
+ * by delimiter. Conversions are supported for any type which folly:to<> can
+ * target, including all overloads of parseTo(). Returns 'true' if the fields
+ * were all successfully populated.  Returns 'false' if there were too few
+ * fields in the input, or too many fields if exact=true.  Casting exceptions
+ * will not be caught.
  *
  * Examples:
  *
@@ -445,20 +469,24 @@ void splitTo(const Delim& delimiter,
  * Note that this will likely not work if the last field's target is of numeric
  * type, in which case folly::to<> will throw an exception.
  */
-template <class T>
-using IsSplitTargetType = std::integral_constant<bool,
-  std::is_arithmetic<T>::value ||
-  std::is_same<T, StringPiece>::value>;
-
-template<bool exact = true,
-         class Delim,
-         class OutputType,
-         class... OutputTypes>
-typename std::enable_if<IsSplitTargetType<OutputType>::value, bool>::type
-split(const Delim& delimiter,
-      StringPiece input,
-      OutputType& outHead,
-      OutputTypes&... outTail);
+namespace detail {
+template <typename Void, typename OutputType>
+struct IsConvertible : std::false_type {};
+
+template <typename OutputType>
+struct IsConvertible<
+    void_t<decltype(parseTo(StringPiece{}, std::declval<OutputType&>()))>,
+    OutputType> : std::true_type {};
+} // namespace detail
+template <typename OutputType>
+struct IsConvertible : detail::IsConvertible<void, OutputType> {};
+
+template <bool exact = true, class Delim, class... OutputTypes>
+typename std::enable_if<
+    StrictConjunction<IsConvertible<OutputTypes>...>::value &&
+        sizeof...(OutputTypes) >= 1,
+    bool>::type
+split(const Delim& delimiter, StringPiece input, OutputTypes&... outputs);
 
 /*
  * Join list of tokens.
@@ -503,18 +531,64 @@ std::string join(const Delim& delimiter,
   return output;
 }
 
+template <
+    class Delim,
+    class Iterator,
+    typename std::enable_if<std::is_same<
+        typename std::iterator_traits<Iterator>::iterator_category,
+        std::random_access_iterator_tag>::value>::type* = nullptr>
+std::string join(const Delim& delimiter, Iterator begin, Iterator end) {
+  std::string output;
+  join(delimiter, begin, end, output);
+  return output;
+}
+
 /**
  * Returns a subpiece with all whitespace removed from the front of @sp.
  * Whitespace means any of [' ', '\n', '\r', '\t'].
  */
-StringPiece skipWhitespace(StringPiece sp);
+StringPiece ltrimWhitespace(StringPiece sp);
+
+/**
+ * Returns a subpiece with all whitespace removed from the back of @sp.
+ * Whitespace means any of [' ', '\n', '\r', '\t'].
+ */
+StringPiece rtrimWhitespace(StringPiece sp);
+
+/**
+ * Returns a subpiece with all whitespace removed from the back and front of @sp.
+ * Whitespace means any of [' ', '\n', '\r', '\t'].
+ */
+inline StringPiece trimWhitespace(StringPiece sp) {
+  return ltrimWhitespace(rtrimWhitespace(sp));
+}
+
+/**
+ * Returns a subpiece with all whitespace removed from the front of @sp.
+ * Whitespace means any of [' ', '\n', '\r', '\t'].
+ * DEPRECATED: @see ltrimWhitespace @see rtrimWhitespace
+ */
+inline StringPiece skipWhitespace(StringPiece sp) {
+  return ltrimWhitespace(sp);
+}
+
+/**
+ *  Strips the leading and the trailing whitespace-only lines. Then looks for
+ *  the least indented non-whitespace-only line and removes its amount of
+ *  leading whitespace from every line. Assumes leading whitespace is either all
+ *  spaces or all tabs.
+ *
+ *  Purpose: including a multiline string literal in source code, indented to
+ *  the level expected from context.
+ */
+std::string stripLeftMargin(std::string s);
 
 /**
  * Fast, in-place lowercasing of ASCII alphabetic characters in strings.
  * Leaves all other characters unchanged, including those with the 0x80
  * bit set.
  * @param str String to convert
- * @param len Length of str, in bytes
+ * @param length Length of str, in bytes
  */
 void toLowerAscii(char* str, size_t length);
 
@@ -522,46 +596,27 @@ inline void toLowerAscii(MutableStringPiece str) {
   toLowerAscii(str.begin(), str.size());
 }
 
-} // namespace folly
-
-// Hash functions to make std::string usable with e.g. hash_map
-//
-// Handle interaction with different C++ standard libraries, which
-// expect these types to be in different namespaces.
-namespace std {
-
-template <class C>
-struct hash<std::basic_string<C> > : private hash<const C*> {
-  size_t operator()(const std::basic_string<C> & s) const {
-    return hash<const C*>::operator()(s.c_str());
-  }
-};
-
+inline void toLowerAscii(std::string& str) {
+  // str[0] is legal also if the string is empty.
+  toLowerAscii(&str[0], str.size());
 }
 
-#if FOLLY_HAVE_DEPRECATED_ASSOC
-#if defined(_GLIBCXX_SYMVER) && !defined(__BIONIC__)
-namespace __gnu_cxx {
-
-template <class C>
-struct hash<std::basic_string<C> > : private hash<const C*> {
-  size_t operator()(const std::basic_string<C> & s) const {
-    return hash<const C*>::operator()(s.c_str());
-  }
+template <
+    class Iterator = const char*,
+    class Base = folly::Range<boost::u8_to_u32_iterator<Iterator>>>
+class UTF8Range : public Base {
+ public:
+  /* implicit */ UTF8Range(const folly::Range<Iterator> baseRange)
+      : Base(boost::u8_to_u32_iterator<Iterator>(
+                 baseRange.begin(), baseRange.begin(), baseRange.end()),
+             boost::u8_to_u32_iterator<Iterator>(
+                 baseRange.end(), baseRange.begin(), baseRange.end())) {}
+  /* implicit */ UTF8Range(const std::string& baseString)
+      : Base(folly::Range<Iterator>(baseString)) {}
 };
 
-}
-#endif
-#endif
-
-// Hook into boost's type traits
-namespace boost {
-template <class T>
-struct has_nothrow_constructor<folly::basic_fbstring<T> > : true_type {
-  enum { value = true };
-};
-} // namespace boost
+using UTF8StringPiece = UTF8Range<const char*>;
 
-#include <folly/String-inl.h>
+} // namespace folly
 
-#endif
+#include <folly/String-inl.h>