[llvm] r282502 - Add llvm::join_items to StringExtras.
Zachary Turner via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 27 09:37:30 PDT 2016
Author: zturner
Date: Tue Sep 27 11:37:30 2016
New Revision: 282502
URL: http://llvm.org/viewvc/llvm-project?rev=282502&view=rev
Log:
Add llvm::join_items to StringExtras.
llvm::join_items is similar to llvm::join, which produces a string
by concatenating a sequence of values together separated by a
given separator. But it differs in that the arguments to
llvm::join() are same-type members of a container, whereas the
arguments to llvm::join_items are arbitrary types passed into
a variadic template. The only requirement on parameters to
llvm::join_items (including for the separator themselves) is
that they be implicitly convertible to std::string or have
an overload of std::string::operator+
Differential Revision: https://reviews.llvm.org/D24880
Added:
llvm/trunk/unittests/ADT/StringExtrasTest.cpp
Modified:
llvm/trunk/include/llvm/ADT/StringExtras.h
llvm/trunk/unittests/ADT/CMakeLists.txt
Modified: llvm/trunk/include/llvm/ADT/StringExtras.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/StringExtras.h?rev=282502&r1=282501&r2=282502&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/StringExtras.h (original)
+++ llvm/trunk/include/llvm/ADT/StringExtras.h Tue Sep 27 11:37:30 2016
@@ -155,6 +155,8 @@ static inline StringRef getOrdinalSuffix
/// it if it is not printable or if it is an escape char.
void PrintEscapedString(StringRef Name, raw_ostream &Out);
+namespace detail {
+
template <typename IteratorT>
inline std::string join_impl(IteratorT Begin, IteratorT End,
StringRef Separator, std::input_iterator_tag) {
@@ -189,12 +191,64 @@ inline std::string join_impl(IteratorT B
return S;
}
+template <typename Sep>
+inline void join_items_impl(std::string &Result, Sep Separator) {}
+
+template <typename Sep, typename Arg>
+inline void join_items_impl(std::string &Result, Sep Separator,
+ const Arg &Item) {
+ Result += Item;
+}
+
+template <typename Sep, typename Arg1, typename... Args>
+inline void join_items_impl(std::string &Result, Sep Separator, const Arg1 &A1,
+ Args &&... Items) {
+ Result += A1;
+ Result += Separator;
+ join_items_impl(Result, Separator, std::forward<Args>(Items)...);
+}
+
+inline size_t join_one_item_size(char C) { return 1; }
+inline size_t join_one_item_size(const char *S) { return S ? ::strlen(S) : 0; }
+
+template <typename T> inline size_t join_one_item_size(const T &Str) {
+ return Str.size();
+}
+
+inline size_t join_items_size() { return 0; }
+
+template <typename A1> inline size_t join_items_size(const A1 &A) {
+ return join_one_item_size(A);
+}
+template <typename A1, typename... Args>
+inline size_t join_items_size(const A1 &A, Args &&... Items) {
+ return join_one_item_size(A) + join_items_size(std::forward<Args>(Items)...);
+}
+}
+
/// Joins the strings in the range [Begin, End), adding Separator between
/// the elements.
template <typename IteratorT>
inline std::string join(IteratorT Begin, IteratorT End, StringRef Separator) {
typedef typename std::iterator_traits<IteratorT>::iterator_category tag;
- return join_impl(Begin, End, Separator, tag());
+ return detail::join_impl(Begin, End, Separator, tag());
+}
+
+/// Joins the strings in the parameter pack \p Items, adding \p Separator
+/// between the elements. All arguments must be implicitly convertible to
+/// std::string, or there should be an overload of std::string::operator+=()
+/// that accepts the argument explicitly.
+template <typename Sep, typename... Args>
+inline std::string join_items(Sep Separator, Args &&... Items) {
+ std::string Result;
+ if (sizeof...(Items) == 0)
+ return Result;
+
+ size_t NS = detail::join_one_item_size(Separator);
+ size_t NI = detail::join_items_size(std::forward<Args>(Items)...);
+ Result.reserve(NI + (sizeof...(Items) - 1) * NS + 1);
+ detail::join_items_impl(Result, Separator, std::forward<Args>(Items)...);
+ return Result;
}
} // End llvm namespace
Modified: llvm/trunk/unittests/ADT/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/CMakeLists.txt?rev=282502&r1=282501&r2=282502&view=diff
==============================================================================
--- llvm/trunk/unittests/ADT/CMakeLists.txt (original)
+++ llvm/trunk/unittests/ADT/CMakeLists.txt Tue Sep 27 11:37:30 2016
@@ -53,6 +53,7 @@ set(ADTSources
SparseBitVectorTest.cpp
SparseMultiSetTest.cpp
SparseSetTest.cpp
+ StringExtrasTest.cpp
StringMapTest.cpp
StringRefTest.cpp
TinyPtrVectorTest.cpp
Added: llvm/trunk/unittests/ADT/StringExtrasTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/StringExtrasTest.cpp?rev=282502&view=auto
==============================================================================
--- llvm/trunk/unittests/ADT/StringExtrasTest.cpp (added)
+++ llvm/trunk/unittests/ADT/StringExtrasTest.cpp Tue Sep 27 11:37:30 2016
@@ -0,0 +1,52 @@
+//===- StringExtrasTest.cpp - Unit tests for String extras ----------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/StringExtras.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+TEST(StringExtrasTest, Join) {
+ std::vector<std::string> Items;
+ EXPECT_EQ("", join(Items.begin(), Items.end(), " <sep> "));
+
+ Items = {"foo"};
+ EXPECT_EQ("foo", join(Items.begin(), Items.end(), " <sep> "));
+
+ Items = {"foo", "bar"};
+ EXPECT_EQ("foo <sep> bar", join(Items.begin(), Items.end(), " <sep> "));
+
+ Items = {"foo", "bar", "baz"};
+ EXPECT_EQ("foo <sep> bar <sep> baz",
+ join(Items.begin(), Items.end(), " <sep> "));
+}
+
+TEST(StringExtrasTest, JoinItems) {
+ const char *Foo = "foo";
+ std::string Bar = "bar";
+ llvm::StringRef Baz = "baz";
+ char X = 'x';
+
+ EXPECT_EQ("", join_items(" <sep> "));
+ EXPECT_EQ("", join_items('/'));
+
+ EXPECT_EQ("foo", join_items(" <sep> ", Foo));
+ EXPECT_EQ("foo", join_items('/', Foo));
+
+ EXPECT_EQ("foo <sep> bar", join_items(" <sep> ", Foo, Bar));
+ EXPECT_EQ("foo/bar", join_items('/', Foo, Bar));
+
+ EXPECT_EQ("foo <sep> bar <sep> baz", join_items(" <sep> ", Foo, Bar, Baz));
+ EXPECT_EQ("foo/bar/baz", join_items('/', Foo, Bar, Baz));
+
+ EXPECT_EQ("foo <sep> bar <sep> baz <sep> x",
+ join_items(" <sep> ", Foo, Bar, Baz, X));
+
+ EXPECT_EQ("foo/bar/baz/x", join_items('/', Foo, Bar, Baz, X));
+}
More information about the llvm-commits
mailing list