/*
- * Copyright 2013 Facebook, Inc.
+ * Copyright 2014 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <stdexcept>
#include <type_traits>
#include <boost/operators.hpp>
+
+// libc++ doesn't provide this header
+#if !FOLLY_USE_LIBCPP
+// This file appears in two locations: inside fbcode and in the
+// libstdc++ source code (when embedding fbstring as std::string).
+// To aid in this schizophrenic use, two macros are defined in
+// c++config.h:
+// _LIBSTDCXX_FBSTRING - Set inside libstdc++. This is useful to
+// gate use inside fbcode v. libstdc++
#include <bits/c++config.h>
+#endif
+
#include "folly/CpuId.h"
#include "folly/Traits.h"
#include "folly/Likely.h"
Range(Iter start, size_t size)
: b_(start), e_(start + size) { }
+#if FOLLY_HAVE_CONSTEXPR_STRLEN
// Works only for Range<const char*>
/* implicit */ constexpr Range(Iter str)
: b_(str), e_(str + strlen(str)) {}
+#else
+ // Works only for Range<const char*>
+ /* implicit */ Range(Iter str)
+ : b_(str), e_(str + strlen(str)) {}
+#endif
// Works only for Range<const char*>
/* implicit */ Range(const std::string& str)
: b_(str.data()), e_(b_ + str.size()) {}
// direction.
template <class OtherIter, typename std::enable_if<
(std::is_same<Iter, const unsigned char*>::value &&
- std::is_same<OtherIter, const char*>::value), int>::type = 0>
+ (std::is_same<OtherIter, const char*>::value ||
+ std::is_same<OtherIter, char*>::value)), int>::type = 0>
/* implicit */ Range(const Range<OtherIter>& other)
: b_(reinterpret_cast<const unsigned char*>(other.begin())),
e_(reinterpret_cast<const unsigned char*>(other.end())) {
}
+ template <class OtherIter, typename std::enable_if<
+ (std::is_same<Iter, unsigned char*>::value &&
+ std::is_same<OtherIter, char*>::value), int>::type = 0>
+ /* implicit */ Range(const Range<OtherIter>& other)
+ : b_(reinterpret_cast<unsigned char*>(other.begin())),
+ e_(reinterpret_cast<unsigned char*>(other.end())) {
+ }
+
template <class OtherIter, typename std::enable_if<
(std::is_same<Iter, const char*>::value &&
- std::is_same<OtherIter, const unsigned char*>::value), int>::type = 0>
+ (std::is_same<OtherIter, const unsigned char*>::value ||
+ std::is_same<OtherIter, unsigned char*>::value)), int>::type = 0>
explicit Range(const Range<OtherIter>& other)
: b_(reinterpret_cast<const char*>(other.begin())),
e_(reinterpret_cast<const char*>(other.end())) {
}
+ template <class OtherIter, typename std::enable_if<
+ (std::is_same<Iter, char*>::value &&
+ std::is_same<OtherIter, unsigned char*>::value), int>::type = 0>
+ explicit Range(const Range<OtherIter>& other)
+ : b_(reinterpret_cast<char*>(other.begin())),
+ e_(reinterpret_cast<char*>(other.end())) {
+ }
+
+ // Allow implicit conversion from Range<From> to Range<To> if From is
+ // implicitly convertible to To.
+ template <class OtherIter, typename std::enable_if<
+ (!std::is_same<Iter, OtherIter>::value &&
+ std::is_convertible<OtherIter, Iter>::value), int>::type = 0>
+ /* implicit */ Range(const Range<OtherIter>& other)
+ : b_(other.begin()),
+ e_(other.end()) {
+ }
+
+ // Allow explicit conversion from Range<From> to Range<To> if From is
+ // explicitly convertible to To.
+ template <class OtherIter, typename std::enable_if<
+ (!std::is_same<Iter, OtherIter>::value &&
+ !std::is_convertible<OtherIter, Iter>::value &&
+ std::is_constructible<Iter, const OtherIter&>::value), int>::type = 0>
+ explicit Range(const Range<OtherIter>& other)
+ : b_(other.begin()),
+ e_(other.end()) {
+ }
+
void clear() {
b_ = Iter();
e_ = Iter();
}
value_type& operator[](size_t i) {
- CHECK_GT(size(), i);
+ DCHECK_GT(size(), i);
return b_[i];
}
const value_type& operator[](size_t i) const {
- CHECK_GT(size(), i);
+ DCHECK_GT(size(), i);
return b_[i];
}
std::swap(e_, rhs.e_);
}
+ /**
+ * Does this Range start with another range?
+ */
+ bool startsWith(const Range& other) const {
+ return size() >= other.size() && subpiece(0, other.size()) == other;
+ }
+ bool startsWith(value_type c) const {
+ return !empty() && front() == c;
+ }
+
+ /**
+ * Does this Range end with another range?
+ */
+ bool endsWith(const Range& other) const {
+ return size() >= other.size() && subpiece(size() - other.size()) == other;
+ }
+ bool endsWith(value_type c) const {
+ return !empty() && back() == c;
+ }
+
+ /**
+ * Remove the given prefix and return true if the range starts with the given
+ * prefix; return false otherwise.
+ */
+ bool removePrefix(const Range& prefix) {
+ return startsWith(prefix) && (b_ += prefix.size(), true);
+ }
+ bool removePrefix(value_type prefix) {
+ return startsWith(prefix) && (++b_, true);
+ }
+
+ /**
+ * Remove the given suffix and return true if the range ends with the given
+ * suffix; return false otherwise.
+ */
+ bool removeSuffix(const Range& suffix) {
+ return endsWith(suffix) && (e_ -= suffix.size(), true);
+ }
+ bool removeSuffix(value_type suffix) {
+ return endsWith(suffix) && (--e_, true);
+ }
+
+ /**
+ * Splits this `Range` `[b, e)` in the position `i` dictated by the next
+ * occurence of `delimiter`.
+ *
+ * Returns a new `Range` `[b, i)` and adjusts this range to start right after
+ * the delimiter's position. This range will be empty if the delimiter is not
+ * found. If called on an empty `Range`, both this and the returned `Range`
+ * will be empty.
+ *
+ * Example:
+ *
+ * folly::StringPiece s("sample string for split_next");
+ * auto p = s.split_step(' ');
+ *
+ * // prints "sample"
+ * cout << s << endl;
+ *
+ * // prints "string for split_next"
+ * cout << p << endl;
+ *
+ * Example 2:
+ *
+ * void tokenize(StringPiece s, char delimiter) {
+ * while (!s.empty()) {
+ * cout << s.split_step(delimiter);
+ * }
+ * }
+ *
+ * @author: Marcelo Juchem <marcelo@fb.com>
+ */
+ Range split_step(value_type delimiter) {
+ auto i = std::find(b_, e_, delimiter);
+ Range result(b_, i);
+
+ b_ = i == e_ ? e_ : std::next(i);
+
+ return result;
+ }
+
+ Range split_step(Range delimiter) {
+ auto i = find(delimiter);
+ Range result(b_, i == std::string::npos ? size() : i);
+
+ b_ = result.end() == e_ ? e_ : std::next(result.end(), delimiter.size());
+
+ return result;
+ }
+
+ /**
+ * Convenience method that calls `split_step()` and passes the result to a
+ * functor, returning whatever the functor does.
+ *
+ * Say you have a functor with this signature:
+ *
+ * Foo fn(Range r) { }
+ *
+ * `split_step()`'s return type will be `Foo`. It works just like:
+ *
+ * auto result = fn(myRange.split_step(' '));
+ *
+ * A functor returning `void` is also supported.
+ *
+ * Example:
+ *
+ * void do_some_parsing(folly::StringPiece s) {
+ * auto version = s.split_step(' ', [&](folly::StringPiece x) {
+ * if (x.empty()) {
+ * throw std::invalid_argument("empty string");
+ * }
+ * return std::strtoull(x.begin(), x.end(), 16);
+ * });
+ *
+ * // ...
+ * }
+ *
+ * @author: Marcelo Juchem <marcelo@fb.com>
+ */
+ template <typename TProcess>
+ auto split_step(value_type delimiter, TProcess &&process)
+ -> decltype(process(std::declval<Range>()))
+ { return process(split_step(delimiter)); }
+
+ template <typename TProcess>
+ auto split_step(Range delimiter, TProcess &&process)
+ -> decltype(process(std::declval<Range>()))
+ { return process(split_step(delimiter)); }
+
private:
Iter b_, e_;
};
}
typedef Range<const char*> StringPiece;
+typedef Range<char*> MutableStringPiece;
typedef Range<const unsigned char*> ByteRange;
+typedef Range<unsigned char*> MutableByteRange;
std::ostream& operator<<(std::ostream& os, const StringPiece& piece);
projects / folly.git / blobdiff