From 742072e606942ffce0c27624a7a63b02fcaca5ba Mon Sep 17 00:00:00 2001
From: Tushar Singh <tusharvickey1999@gmail.com>
Date: Wed, 12 Jul 2023 12:21:25 +0530
Subject: [PATCH] add VTSubParameters class

---
 src/terminal/adapter/DispatchTypes.hpp        | 50 +++++++++++++++++--
 src/terminal/adapter/adaptDispatch.hpp        |  2 +-
 .../adapter/adaptDispatchGraphics.cpp         |  2 +-
 3 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/src/terminal/adapter/DispatchTypes.hpp b/src/terminal/adapter/DispatchTypes.hpp
index 8a199a196735..088714e5cf90 100644
--- a/src/terminal/adapter/DispatchTypes.hpp
+++ b/src/terminal/adapter/DispatchTypes.hpp
@@ -152,6 +152,48 @@ namespace Microsoft::Console::VirtualTerminal
         VTInt _value;
     };
 
+    class VTSubParameters
+    {
+    public:
+        constexpr VTSubParameters() noexcept
+        {
+        }
+        
+        constexpr VTSubParameters(const std::span<const VTParameter> subParams) noexcept :
+            _subParams{ subParams }
+        {
+        }
+
+        constexpr VTParameter at(const size_t index) const noexcept
+        {
+            return til::at(_subParams, index);
+        }
+
+        VTSubParameters subspan(const size_t offset, const size_t count) const noexcept
+        {
+            const auto subParamsSpan = _subParams.subspan(offset, count);
+            return { subParamsSpan };
+        }
+
+        bool empty() const noexcept
+        {
+            return _subParams.empty();
+        }
+
+        size_t size() const noexcept
+        {
+            return _subParams.size();
+        }
+
+        constexpr operator std::span<const VTParameter>() const noexcept
+        {
+            return _subParams;
+        }
+
+    private:
+        std::span<const VTParameter> _subParams;
+    };
+
     class VTParameters
     {
     public:
@@ -200,10 +242,10 @@ namespace Microsoft::Console::VirtualTerminal
             // _subParams as is and create new span for others.
             const auto newParamsSpan = _params.subspan(std::min(offset, _params.size()));
             const auto newSubParamRangesSpan = _subParamRanges.subspan(std::min(offset, _subParamRanges.size()));
-            return { newParamsSpan, _subParams, newSubParamRangesSpan };
+            return { newParamsSpan, _subParams , newSubParamRangesSpan };
         }
 
-        std::span<const VTParameter> subParamsFor(const size_t index) const noexcept
+        VTSubParameters subParamsFor(const size_t index) const noexcept
         {
             if (index < _subParamRanges.size())
             {
@@ -212,7 +254,7 @@ namespace Microsoft::Console::VirtualTerminal
             }
             else
             {
-                return std::span<const VTParameter>{};
+                return VTSubParameters{};
             }
         }
 
@@ -259,7 +301,7 @@ namespace Microsoft::Console::VirtualTerminal
         static constexpr std::span defaultParameters{ &defaultParameter, 1 };
 
         std::span<const VTParameter> _params;
-        std::span<const VTParameter> _subParams;
+        VTSubParameters _subParams;
         std::span<const std::pair<BYTE, BYTE>> _subParamRanges;
     };
 
diff --git a/src/terminal/adapter/adaptDispatch.hpp b/src/terminal/adapter/adaptDispatch.hpp
index 059fb3852c5c..e0c346dc9d0b 100644
--- a/src/terminal/adapter/adaptDispatch.hpp
+++ b/src/terminal/adapter/adaptDispatch.hpp
@@ -301,7 +301,7 @@ namespace Microsoft::Console::VirtualTerminal
                                     const size_t optionIndex,
                                     TextAttribute& attr) noexcept;
         void _ApplyGraphicsOptionSubParam(const VTParameter option,
-                                          const std::span<const VTParameter> subParams,
+                                          const VTSubParameters subParams,
                                           TextAttribute& attr) noexcept;
         void _ApplyGraphicsOptions(const VTParameters options,
                                    TextAttribute& attr) noexcept;
diff --git a/src/terminal/adapter/adaptDispatchGraphics.cpp b/src/terminal/adapter/adaptDispatchGraphics.cpp
index cd05158fe991..5259cf8ce64f 100644
--- a/src/terminal/adapter/adaptDispatchGraphics.cpp
+++ b/src/terminal/adapter/adaptDispatchGraphics.cpp
@@ -268,7 +268,7 @@ size_t AdaptDispatch::_ApplyGraphicsOption(const VTParameters options,
 // Return Value:
 // - <None>
 void AdaptDispatch::_ApplyGraphicsOptionSubParam(const VTParameter /* option */,
-                                                 const std::span<const VTParameter> /* subParam */,
+                                                 const VTSubParameters /* subParam */,
                                                  TextAttribute& /* attr */) noexcept
 {
     // here, we apply our "best effort" rule, while handling sub params if we don't