Add distance functions to TextPosition and TextRange.

include/eepp/ui/doc/textposition.hpp

@@ -81,6 +81,10 @@ class EE_API TextPosition {
 		return {};
 	}
 
+	Int64 distance( const TextPosition& other ) const {
+		return std::abs( mLine - other.mLine ) + std::abs( mColumn - other.mColumn );
+	}
+
   private:
 	Int64 mLine{ 0xffffffff };
 	Int64 mColumn{ 0xffffffff };

include/eepp/ui/doc/textrange.hpp

@@ -120,6 +120,8 @@ class EE_API TextRange {
 	static TextRange convertToLineColumn( const std::string_view& text, Int64 startOffset,
 										  Int64 endOffset );
 
+    Int64 minimumDistance(const TextRange& other) const;
+
   private:
 	TextPosition mStart;
 	TextPosition mEnd;

src/eepp/ui/doc/textrange.cpp

@@ -1,5 +1,6 @@
 #include <eepp/core/debug.hpp>
 #include <eepp/ui/doc/textrange.hpp>
+#include <limits>
 
 namespace EE { namespace UI { namespace Doc {
 
@@ -163,6 +164,25 @@ TextRange TextRange::convertToLineColumn( const std::string_view& text, Int64 st
 	return convertToLineColumn<std::string_view>( text, startOffset, endOffset );
 }
 
+Int64 TextRange::minimumDistance( const TextRange& other ) const {
+	if ( intersects( other ) )
+		return 0;
+
+	auto minDist = std::numeric_limits<Int64>::max();
+
+	const TextPosition corners1[] = { mStart, mEnd };
+	const TextPosition corners2[] = { other.start(), other.end() };
+
+	for ( const auto& c1 : corners1 ) {
+		for ( const auto& c2 : corners2 ) {
+			auto dist = c1.distance( c2 );
+			minDist = std::min( minDist, dist );
+		}
+	}
+
+	return minDist;
+}
+
 TextRanges::TextRanges() {}
 
 TextRanges::TextRanges( const std::vector<TextRange>& ranges ) : std::vector<TextRange>( ranges ) {}