Add `e_repeat` expression. Update version.

CMakeLists.txt

@@ -5,7 +5,7 @@ include(FetchContent)
 
 project(
     simstr
-    VERSION 1.2.8
+    VERSION 1.2.9
     DESCRIPTION "Yet another modern C++ string library"
     HOMEPAGE_URL "https://github.com/orefkov/simstr"
     LANGUAGES CXX
@@ -27,6 +27,7 @@ endif()
 
 option(SIMSTR_BUILD_TESTS "Build tests" ON)
 option(SIMSTR_BENCHMARKS "Build benchmarks" Off)
+option(USE_SYSTEM_DEPS "Use system dependencies" Off)
 cmake_dependent_option(SIMSTR_LINK_NATVIS "Link natvis file" On CAN_LINK_NATVIS Off)
 
 add_library(simstr_simstr
@@ -92,7 +93,11 @@ function(add_simdutf)
     FetchContent_MakeAvailable(simdutf)
 endfunction()
 
-add_simdutf()
+if (USE_SYSTEM_DEPS)
+    find_package(simdutf REQUIRED)
+else ()
+    add_simdutf()
+endif()
 
 target_link_libraries(simstr_simstr PUBLIC simdutf::simdutf)
 

docs/Doxyfile

@@ -48,7 +48,7 @@ PROJECT_NAME           = "simstr"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 1.2.8
+PROJECT_NUMBER         = 1.2.9
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewers a

docs/Doxyfile_ru

@@ -48,7 +48,7 @@ PROJECT_NAME           = "simstr"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 1.2.8
+PROJECT_NUMBER         = 1.2.9
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewers a

docs/overview.md

@@ -474,6 +474,11 @@ The number of characters and the symbol can be specified at runtime. Shorthand n
 
     e_c(NumberOfCharacters, Symbol)
 
+#### e_repeat{Str, count}
+Generates a repetition of a string literal or expression `Str` `count` times.
+
+    e_repeat("aa", 10);
+
 #### e_choice(bool Condition, StrExpr1, StrExpr2)
 If Condition == true, the result will be StrExpr1, otherwise StrExpr2.
 

docs/overview_ru.md

@@ -476,6 +476,11 @@
 
     e_c(КоличествоСимволов, Символ)
 
+#### e_repeat{Str, count}
+Генерирует повторение строкового литерала или выражения `Str` `count` раз.
+
+    e_repeat("aa", 10);
+
 #### e_choice(bool Condition, StrExpr1, StrExpr2)
 Если Condition == true, результат будет равен StrExpr1, иначе StrExpr2.
 

include/simstr/strexpr.h

@@ -814,6 +814,75 @@ constexpr inline auto e_c(size_t l, K s) {
     return expr_pad<K>{ l, s };
 }
 
+template<typename K, size_t N>
+struct expr_repeat_lit {
+    using symb_type = K;
+    size_t repeat_;
+    const K (&s)[N + 1];
+    constexpr size_t length() const noexcept {
+        return N * repeat_;
+    }
+    constexpr symb_type* place(symb_type* p) const noexcept {
+        for (size_t i = 0; i < repeat_; i++) {
+            std::char_traits<K>::copy(p, s, N);
+            p += N;
+        }
+        return p;
+    }
+};
+
+template<StrExpr A>
+struct expr_repeat_expr {
+    using symb_type = typename A::symb_type;
+    size_t repeat_;
+    const A& expr_;
+    constexpr size_t length() const noexcept {
+        return repeat_ * expr_.length();
+    }
+    constexpr symb_type* place(symb_type* p) const noexcept {
+        for (size_t i = 0; i < repeat_; i++) {
+            p = expr_.place(p);
+        }
+        return p;
+    }
+};
+
+/*!
+ * @ingroup StrExprs
+ * @ru @brief Генерирует строку из l строковых констант s типа K
+ * @tparam K - тип символа
+ * @param l - количество повторов
+ * @param s - строковый литерал
+ * @return строковое выражение, генерирующее строку из l строк s
+ * @en @brief Generate a string from l string constants s of type K
+ * @tparam K - character type
+ * @param l - number of repetitions
+ * @param s - string literal
+ * @return a string expression generating a string of l strings s
+ */
+template<typename T, typename K = const_lit<T>::symb_type, size_t M = const_lit<T>::Count> requires (M > 0)
+constexpr inline auto e_repeat(T&& s, size_t l) {
+    return expr_repeat_lit<K, M - 1>{ l, s };
+}
+
+/*!
+ * @ingroup StrExprs
+ * @ru @brief Генерирует строку из l строковых выражений s типа K
+ * @tparam K - тип символа
+ * @param l - количество повторов
+ * @param s - строковое выражение
+ * @return строковое выражение, генерирующее строку из l строковых выражений s
+ * @en @brief Generate a string from l string expressions s of type K
+ * @tparam K - character type
+ * @param l - number of repetitions
+ * @param s - string expression
+ * @return a string expression generating a string of l string expressions s
+ */
+template<StrExpr A>
+constexpr inline auto e_repeat(const A& s, size_t l) {
+    return expr_repeat_expr<A>{ l, s };
+}
+
 /*!
  * @ingroup StrExprs
  * @ru @brief Строковое выражение условного выбора.

readme.md

@@ -1,7 +1,7 @@
 # simstr - String object and function library
 [![CMake on multiple platforms](https://github.com/orefkov/simstr/actions/workflows/cmake-multi-platform.yml/badge.svg)](https://github.com/orefkov/simstr/actions/workflows/cmake-multi-platform.yml)
 
-Version 1.2.8.
+Version 1.2.9.
 
 <span class="obfuscator"><a href="readme_ru.md">On Russian | По-русски</a></span>
 

readme_ru.md

@@ -1,7 +1,7 @@
 # simstr - библиотека строковых объектов и функций
 [![CMake on multiple platforms](https://github.com/orefkov/simstr/actions/workflows/cmake-multi-platform.yml/badge.svg)](https://github.com/orefkov/simstr/actions/workflows/cmake-multi-platform.yml)
 
-Версия 1.2.8.
+Версия 1.2.9.
 
 <span class="obfuscator"><a href="readme.md">On English | По-английски</a></span>
 

tests/test_str.cpp

@@ -1769,4 +1769,10 @@ TEST(SimStr, HashStrMapAt) {
     EXPECT_EQ(test.find("Test")->second, 2);
 }
 
+TEST(SimStr, ExprRepeat) {
+    EXPECT_EQ(stringa{e_repeat("aa", 3)}, "aaaaaa");
+    int t = 1;
+    EXPECT_EQ(lstringa<40>{e_repeat("aa"_ss + t + "_", 3)}, "aa1_aa1_aa1_");
+}
+
 } // namespace simstr::tests