From a71d028a874e6ce2942bf8980c175dd151e3d8ee Mon Sep 17 00:00:00 2001
From: m-peko <mpeko00@fesb.hr>
Date: Thu, 28 May 2020 08:06:39 +0200
Subject: [PATCH] Use std::string_view instead of std::string in split_range

---
 include/booleval/utils/split_range.hpp | 47 ++++++++++++--------------
 src/token/tokenizer.cpp                |  9 ++---
 2 files changed, 23 insertions(+), 33 deletions(-)

diff --git a/include/booleval/utils/split_range.hpp b/include/booleval/utils/split_range.hpp
index 29522bf..6f67d6b 100644
--- a/include/booleval/utils/split_range.hpp
+++ b/include/booleval/utils/split_range.hpp
@@ -30,7 +30,6 @@
 #ifndef BOOLEVAL_SPLIT_RANGE_H
 #define BOOLEVAL_SPLIT_RANGE_H
 
-#include <string>
 #include <iterator>
 #include <algorithm>
 #include <string_view>
@@ -73,11 +72,10 @@ class split_range {
         using reference         = value_type&;
 
     public:
-        explicit constexpr iterator(std::string_view strv, std::string const& delims) noexcept
+        explicit constexpr iterator(std::string_view strv, std::string_view delims) noexcept
             : strv_(strv),
               delims_(delims),
               prev_(std::begin(strv_)) {
-            apply_split_options();
             next();
         }
 
@@ -88,17 +86,17 @@ class split_range {
         iterator& operator=(iterator const& rhs) = default;
 
         [[nodiscard]] constexpr auto operator*() const noexcept {
-            return curr_elem_;
+            return curr_value_;
         }
 
         [[nodiscard]] constexpr auto operator->() const noexcept {
-            return &curr_elem_;
+            return &curr_value_;
         }
 
         constexpr iterator& operator++() noexcept {
-            ++curr_elem_.index;
+            ++curr_value_.index;
 
-            if (curr_elem_.quoted) {
+            if (curr_value_.quoted) {
                 curr_ = skip_char(curr_, whitespace_char);
                 if (std::end(strv_) != curr_ && curr_ != std::prev(std::end(strv_))) {
                     curr_ = std::next(curr_);
@@ -119,7 +117,7 @@ class split_range {
                 }
             }
 
-            curr_elem_.quoted = false;
+            curr_value_.quoted = false;
 
             next();
             return *this;
@@ -146,15 +144,6 @@ class split_range {
             : prev_(end)
         {}
 
-        /**
-         * Applies splitting options to the string containing delimiters.
-         */
-        constexpr void apply_split_options() noexcept {
-            if constexpr (is_set(iter_options, split_options::split_by_whitespace)) {
-                delims_.append(1, ' ');
-            }
-        }
-
         /**
          * Finds the iterator pointing to the beginning of the next token in the specified range.
          *
@@ -166,7 +155,7 @@ class split_range {
         [[nodiscard]] constexpr std::string_view::iterator find_next(std::string_view::iterator first,
                                                                      std::string_view::iterator last) const noexcept {
             if constexpr (is_set(iter_options, split_options::allow_quoted_strings)) {
-                if (curr_elem_.quoted) {
+                if (curr_value_.quoted) {
                     return find_next_quote(first, last);
                 } else {
                     return std::min(
@@ -189,7 +178,13 @@ class split_range {
          */
         [[nodiscard]] constexpr std::string_view::iterator find_next_delim(std::string_view::iterator first,
                                                                            std::string_view::iterator last) const noexcept {
-            return std::find_first_of(first, last, std::begin(delims_), std::end(delims_));
+            if constexpr (is_set(iter_options, split_options::split_by_whitespace)) {
+                auto whitespace = std::find(first, last, whitespace_char);
+                auto other_delim = std::find_first_of(first, last, std::begin(delims_), std::end(delims_));
+                return std::min(whitespace, other_delim);
+            } else {
+                return std::find_first_of(first, last, std::begin(delims_), std::end(delims_));
+            }
         }
 
         /**
@@ -227,12 +222,12 @@ class split_range {
                 return;
             }
 
-            curr_elem_.quoted = false;
+            curr_value_.quoted = false;
             curr_ = find_next(prev_, std::end(strv_));
 
             if (std::end(strv_) != curr_) {
                 if (iter_quote_char == *curr_) {
-                    curr_elem_.quoted = true;
+                    curr_value_.quoted = true;
                     prev_ = skip_char(curr_, iter_quote_char);
                     curr_ = find_next(prev_, std::end(strv_));
                 } else {
@@ -248,7 +243,7 @@ class split_range {
                 return;
             }
 
-            curr_elem_.value = strv_.substr(
+            curr_value_.value = strv_.substr(
                 std::distance(std::begin(strv_), prev_),
                 std::distance(prev_, curr_)
             );
@@ -256,18 +251,18 @@ class split_range {
 
     private:
         std::string_view strv_;
-        std::string delims_;
+        std::string_view delims_;
 
         std::string_view::iterator prev_;
         std::string_view::iterator curr_;
 
-        element curr_elem_;
+        value_type curr_value_;
     };
 
 public:
     constexpr split_range() = default;
 
-	constexpr split_range(std::string_view strv, std::string const& delims = " ")
+	constexpr split_range(std::string_view strv, std::string_view delims = " ")
         : strv_(strv),
           delims_(delims)
     {}
@@ -300,7 +295,7 @@ class split_range {
 
 private:
     std::string_view strv_;
-    std::string delims_;
+    std::string_view delims_;
 };
 
 } // utils
diff --git a/src/token/tokenizer.cpp b/src/token/tokenizer.cpp
index 968712a..fe38ae8 100644
--- a/src/token/tokenizer.cpp
+++ b/src/token/tokenizer.cpp
@@ -74,13 +74,8 @@ void tokenizer::tokenize() {
         utils::split_options::split_by_whitespace |
         utils::split_options::allow_quoted_strings;
 
-    auto tokens_range = utils::split_range<options>(
-        expression_,
-        utils::join(
-            std::begin(single_char_symbols),
-            std::end(single_char_symbols)
-        )
-    );
+    auto delims = utils::join(std::begin(single_char_symbols), std::end(single_char_symbols));
+    auto tokens_range = utils::split_range<options>(expression_, delims);
 
     for (auto const& [quoted, index, value] : tokens_range) {
         auto type = quoted ? token_type::field : map_to_token_type(value);