3 files changed, 59 insertions, 3 deletions

diff --git a/include/cru/common/String.hpp b/include/cru/common/String.hpp
index 8db012cb..e7688555 100644
--- a/include/cru/common/String.hpp
+++ b/include/cru/common/String.hpp
@@ -4,6 +4,7 @@
 #include "Range.hpp"
 #include "StringUtil.hpp"
 
+#include <double-conversion/double-conversion.h>
 #include <algorithm>
 #include <array>
 #include <charconv>
@@ -23,6 +24,9 @@ class StringView;
 
 class CRU_BASE_API String {
  public:
+  static double_conversion::StringToDoubleConverter
+      kDefaultStringToDoubleConverter;
+
   using value_type = char16_t;
   using size_type = Index;
   using difference_type = Index;
@@ -195,6 +199,8 @@ class CRU_BASE_API String {
   String& TrimEnd();
   String& Trim();
 
+  std::vector<String> Split(value_type separator,
+                            bool remove_space_line = false) const;
   std::vector<String> SplitToLines(bool remove_space_line = false) const;
 
   bool StartWith(StringView str) const;
@@ -225,6 +231,9 @@ class CRU_BASE_API String {
 
   int Compare(const String& other) const;
 
+  float ParseToFloat(Index* processed_characters_count = nullptr) const;
+  double ParseToDouble(Index* processed_characters_count = nullptr) const;
+
  private:
   static char16_t kEmptyBuffer[1];
 
diff --git a/src/common/String.cpp b/src/common/String.cpp
index 9366abeb..48705d3b 100644
--- a/src/common/String.cpp
+++ b/src/common/String.cpp
@@ -2,6 +2,7 @@
 #include "cru/common/Exception.hpp"
 #include "cru/common/StringUtil.hpp"
 
+#include <cmath>
 #include <gsl/gsl>
 
 #include <algorithm>
@@ -10,6 +11,15 @@
 #include <string_view>
 
 namespace cru {
+double_conversion::StringToDoubleConverter
+    String::kDefaultStringToDoubleConverter(
+        double_conversion::StringToDoubleConverter::ALLOW_TRAILING_JUNK |
+            double_conversion::StringToDoubleConverter::ALLOW_LEADING_SPACES |
+            double_conversion::StringToDoubleConverter::ALLOW_TRAILING_SPACES |
+            double_conversion::StringToDoubleConverter::
+                ALLOW_CASE_INSENSIBILITY,
+        0.0, NAN, "infinity", "nan");
+
 template <typename C>
 Index GetStrSize(const C* str) {
   Index i = 0;
@@ -261,7 +271,8 @@ String& String::Trim() {
   return *this;
 }
 
-std::vector<String> String::SplitToLines(bool remove_space_line) const {
+std::vector<String> String::Split(value_type separator,
+                                  bool remove_space_line) const {
   std::vector<String> result;
 
   if (size_ == 0) return result;
@@ -269,7 +280,7 @@ std::vector<String> String::SplitToLines(bool remove_space_line) const {
   Index line_start = 0;
   Index line_end = 0;
   while (line_end < size_) {
-    if (buffer_[line_end] == '\n') {
+    if (buffer_[line_end] == separator) {
       if (remove_space_line) {
         bool add = false;
         for (Index i = line_start; i < line_end; i++) {
@@ -305,6 +316,10 @@ std::vector<String> String::SplitToLines(bool remove_space_line) const {
   return result;
 }
 
+std::vector<String> String::SplitToLines(bool remove_space_line) const {
+  return Split(u'\n', remove_space_line);
+}
+
 bool String::StartWith(StringView str) const {
   if (str.size() > size_) return false;
   return std::memcmp(str.data(), buffer_, str.size()) == 0;
@@ -419,6 +434,26 @@ int StringView::Compare(const StringView& other) const {
   }
 }
 
+float String::ParseToFloat(Index* processed_characters_count) const {
+  int pcc;
+  auto result = kDefaultStringToDoubleConverter.StringToFloat(
+      reinterpret_cast<const uc16*>(buffer_), static_cast<int>(size_), &pcc);
+  if (processed_characters_count != nullptr) {
+    *processed_characters_count = pcc;
+  }
+  return result;
+}
+
+double String::ParseToDouble(Index* processed_characters_count) const {
+  int pcc;
+  auto result = kDefaultStringToDoubleConverter.StringToDouble(
+      reinterpret_cast<const uc16*>(buffer_), static_cast<int>(size_), &pcc);
+  if (processed_characters_count != nullptr) {
+    *processed_characters_count = pcc;
+  }
+  return result;
+}
+
 StringView StringView::substr(Index pos) {
   Expects(pos >= 0 && pos < size_);
   return StringView(ptr_ + pos, size_ - pos);
diff --git a/test/common/StringTest.cpp b/test/common/StringTest.cpp
index 7198f47b..737a93ad 100644
--- a/test/common/StringTest.cpp
+++ b/test/common/StringTest.cpp
@@ -1,5 +1,5 @@
-#include "cru/common/String.hpp"
 #include "cru/common/Format.hpp"
+#include "cru/common/String.hpp"
 
 #include <gtest/gtest.h>
 
@@ -69,3 +69,15 @@ TEST(String, SplitToLinesRemoveSpaceLine) {
   ASSERT_EQ(lines[1], String(u"def"));
   ASSERT_EQ(lines[2], String(u"ghi"));
 }
+
+TEST(String, ParseToFloat) {
+  using cru::String;
+  ASSERT_EQ(String(u"3.14159").ParseToDouble(), 3.14159);
+  ASSERT_EQ(String(u"   3.14159").ParseToDouble(), 3.14159);
+  ASSERT_EQ(String(u"   3.14159    ").ParseToDouble(), 3.14159);
+
+  cru::Index processed_char_count = 0;
+  ASSERT_EQ(String(u" 3.14159 garbege").ParseToDouble(&processed_char_count),
+            3.14159);
+  ASSERT_EQ(processed_char_count, 9);
+}