From 6963dd82cd4a1c44e76b44a1b626d701fe0ebb15 Mon Sep 17 00:00:00 2001
From: Christian Zimmermann <christian.zimmermann@ur.de>
Date: Tue, 13 Dec 2022 19:19:41 +0100
Subject: [PATCH] index utils: index depth/dimension

---
 src/include/ranges/index_utils.cc.h | 106 ++++++++++++++++++++++++++++
 src/include/ranges/index_utils.h    |   6 ++
 2 files changed, 112 insertions(+)

diff --git a/src/include/ranges/index_utils.cc.h b/src/include/ranges/index_utils.cc.h
index 8d1f9c7..66f0569 100644
--- a/src/include/ranges/index_utils.cc.h
+++ b/src/include/ranges/index_utils.cc.h
@@ -71,6 +71,112 @@ namespace CNORZX
 	}
     }
 
+    template <class Index>
+    constexpr decltype(auto) getIndexDepth(const Index& ind)
+    {
+	static_assert(is_index<Index>::value, "got non-index type");
+	if constexpr(has_sub<Index>::value){
+	    if constexpr(has_static_sub<Index>::value){
+		constexpr SizeT D = index_dim<Index>::value;
+		return iter<0,D>
+		    ( [&](auto i) { return getIndexDepth(*std::get<i>(ind.pack())); },
+		      [](auto... e) {
+			  if constexpr( is_integral_constant<decltype(e)>::value and ... ){
+			      return std::integral_constant<SizeT,std::max({e...})> {};
+			  }
+			  else {
+			      return std::max({e...});
+			  }
+		      } );
+	    }
+	    else {
+		SizeT o = 0;
+		if(ind.dim() == 1){
+		    auto p = ind.pack();
+		    if(p.size() == 0){
+			o = 1;
+		    }
+		    else {
+			o = getIndexDepth(*p[0]);
+		    }
+		}
+		else {
+		    for(SizeT i = 0; i != ind.dim(); ++i){
+			const SizeT e = getIndexDepth(*ind.pack()[i]);
+			if(e > o){
+			    o = e;
+			}
+		    }
+		}
+		return o;
+	    }
+	}
+	else {
+	    return std::integral_constant<SizeT,1> {};
+	}
+    }
+
+    template <class Index, typename IntT>
+    constexpr decltype(auto) getDimension(const Index& ind, IntT depth)
+    {
+	static_assert(is_index<Index>::value, "got non-index type");
+	if constexpr(std::is_same<std::integral_constant<SizeT,0>,IntT>::value) {
+	    return std::integral_constant<SizeT,1> {}
+	}
+	else {
+	    auto iminus = [](auto i) {
+		if constexpr( is_integral_constant<decltype(i)>::value ) {
+		    return std::integral_constant<SizeT,i-1> {}
+		}
+		else {
+		    return i-1;
+		}
+	    };
+	    if constexpr(has_sub<Index>::value){
+		if constexpr(has_static_sub<Index>::value and is_integral_constant<IntT>::value){
+		    constexpr SizeT D = index_dim<Index>::value;
+		    return iter<0,D>
+			( [&](auto i) { return getDimension(*std::get<i>(ind.pack()),
+							    iminus(depth)); },
+			    [](auto... e) {
+				if constexpr( is_integral_constant<decltype(e)>::value and ... ){
+				    return std::integral_constant<SizeT,(e + ...)> {};
+				}
+				else {
+				    return (e + ...);
+				}
+			    } );
+		}
+		else {
+		    SizeT o = 0;
+		    if(depth == 0u){
+			o = 1;
+		    }
+		    else if(ind.dim() == 1){
+			auto p = ind.pack();
+			if(p.size() == 0){
+			    o = 1;
+			}
+			else {
+			    o = getDimension(*p[0], iminus(depth));
+			}
+		    }
+		    else {
+			for(SizeT i = 0; i != ind.dim(); ++i){
+			    const SizeT e = getDimension(*ind.pack()[i], iminus(depth));
+			    if(e > o){
+				o = e;
+			    }
+			}
+		    }
+		    return o;
+		}
+	    }
+	    else {
+		return std::integral_constant<SizeT,1> {};
+	    }
+	}
+    }
 }
 
 #endif
diff --git a/src/include/ranges/index_utils.h b/src/include/ranges/index_utils.h
index 73ec4e2..cafaa2f 100644
--- a/src/include/ranges/index_utils.h
+++ b/src/include/ranges/index_utils.h
@@ -13,6 +13,12 @@ namespace CNORZX
 
     template <class F>
     inline decltype(auto) indexPackZip(const Vector<XIndexPtr>& a, const Vector<XIndexPtr>& b, F&& f);
+
+    template <class Index>
+    constexpr decltype(auto) getIndexDepth(const Index& ind);
+
+    template <class Index, typename IntT>
+    constexpr decltype(auto) getDimension(const Index& ind, IntT depth);
 }
 
 #endif