From c50072b108198a5c278c16967b700c713b0140a8 Mon Sep 17 00:00:00 2001
From: memchr <118117622+memchr@users.noreply.github.com>
Date: Tue, 19 Sep 2023 08:44:54 +0000
Subject: [PATCH] varlist: cleanup unintuitive string splitting (#3369)

* refactor(varlist): replace unintuitive string splitting

* refactor(varlist): remove test asserts
---
 src/helpers/VarList.cpp | 46 ++++++++++++++++-------------------------
 src/helpers/VarList.hpp | 10 ++++++---
 2 files changed, 25 insertions(+), 31 deletions(-)

diff --git a/src/helpers/VarList.cpp b/src/helpers/VarList.cpp
index 0da86e15..c29a1e96 100644
--- a/src/helpers/VarList.cpp
+++ b/src/helpers/VarList.cpp
@@ -1,36 +1,26 @@
 #include "VarList.hpp"
+#include <ranges>
+#include <algorithm>
 
-CVarList::CVarList(const std::string& in, long unsigned int lastArgNo, const char separator) {
-    std::string curitem  = "";
-    std::string argZ     = in;
-    const bool  SPACESEP = separator == 's';
+CVarList::CVarList(const std::string& in, const size_t lastArgNo, const char delim, const bool removeEmpty) {
+    if (in.empty())
+        m_vArgs.emplace_back("");
 
-    auto        nextItem = [&]() {
-        auto idx = lastArgNo != 0 && m_vArgs.size() >= lastArgNo - 1 ? std::string::npos : ([&]() -> size_t {
-            if (!SPACESEP)
-                return argZ.find_first_of(separator);
+    std::string args{in};
+    size_t      idx = 0;
+    size_t      pos = 0;
+    std::ranges::replace_if(
+        args, [&](const char& c) { return delim == 's' ? std::isspace(c) : c == delim; }, 0);
 
-            uint64_t pos = -1;
-            while (!std::isspace(argZ[++pos]) && pos < argZ.length())
-                ;
-
-            return pos < argZ.length() ? pos : std::string::npos;
-        }());
-
-        if (idx != std::string::npos) {
-            curitem = argZ.substr(0, idx);
-            argZ    = argZ.substr(idx + 1);
-        } else {
-            curitem = argZ;
-            argZ    = STRVAL_EMPTY;
+    for (const auto& s : args | std::views::split(0)) {
+        if (removeEmpty && s.empty())
+            continue;
+        if (++idx == lastArgNo) {
+            m_vArgs.emplace_back(removeBeginEndSpacesTabs(in.substr(pos)));
+            break;
         }
-    };
-
-    nextItem();
-
-    while (curitem != STRVAL_EMPTY) {
-        m_vArgs.push_back(removeBeginEndSpacesTabs(curitem));
-        nextItem();
+        pos += s.size() + 1;
+        m_vArgs.emplace_back(removeBeginEndSpacesTabs(std::string_view{s}.data()));
     }
 }
 
diff --git a/src/helpers/VarList.hpp b/src/helpers/VarList.hpp
index 0c83a3db..60e9a551 100644
--- a/src/helpers/VarList.hpp
+++ b/src/helpers/VarList.hpp
@@ -5,8 +5,12 @@
 
 class CVarList {
   public:
-    /* passing 's' as a separator will use std::isspace */
-    CVarList(const std::string& in, long unsigned int lastArgNo = 0, const char separator = ',');
+    /** Split string into arg list
+        @param lastArgNo stop splitting after argv reaches maximum size, last arg will contain rest of unsplit args
+        @param delim if delimiter is 's', use std::isspace
+        @param removeEmpty remove empty args from argv
+    */
+    CVarList(const std::string& in, const size_t maxSize = 0, const char delim = ',', const bool removeEmpty = false);
 
     ~CVarList() = default;
 
@@ -16,7 +20,7 @@ class CVarList {
 
     std::string join(const std::string& joiner, size_t from = 0, size_t to = 0) const;
 
-    std::string operator[](const long unsigned int& idx) const {
+    std::string operator[](const size_t& idx) const {
         if (idx >= m_vArgs.size())
             return "";
         return m_vArgs[idx];