Backport: Allow setting value at end of a SparseVector.

Change representation of SparseVector in tests so last value can be seen.

Backport of changeset 7778:b7842ad8047b.

3 files changed, 74 insertions, 36 deletions

diff --git a/src/SparseVector.h b/src/SparseVector.h
index 67ad1e1e3..6dd02ba8b 100644
--- a/src/SparseVector.h
+++ b/src/SparseVector.h
@@ -12,13 +12,17 @@ namespace Scintilla {
 
 // SparseVector is similar to RunStyles but is more efficient for cases where values occur
 // for one position instead of over a range of positions.
+// There are always elements at the start and end, so the element type should have
+// a reasonable empty value that will cause no problems.
+// The element type should have a noexcept default constructor as that allows methods to
+// be noexcept.
 template <typename T>
 class SparseVector {
 private:
 	std::unique_ptr<Partitioning<Sci::Position>> starts;
 	std::unique_ptr<SplitVector<T>> values;
-	T empty;
-	void ClearValue(Sci::Position partition) {
+	T empty;	// Return from ValueAt when no element at a position.
+	void ClearValue(Sci::Position partition) noexcept {
 		values->SetValueAt(partition, T());
 	}
 public:
@@ -40,18 +44,25 @@ public:
 		}
 		values.reset();
 	}
-	Sci::Position Length() const {
-		return starts->PositionFromPartition(starts->Partitions());
+	Sci::Position Length() const noexcept {
+		return starts->Length();
 	}
-	Sci::Position Elements() const {
+	Sci::Position Elements() const noexcept {
 		return starts->Partitions();
 	}
-	Sci::Position PositionOfElement(int element) const {
+	Sci::Position PositionOfElement(Sci::Position element) const noexcept {
 		return starts->PositionFromPartition(element);
 	}
-	const T& ValueAt(Sci::Position position) const {
-		assert(position < Length());
-		const Sci::Position partition = starts->PartitionFromPosition(position);
+	Sci::Position ElementFromPosition(Sci::Position position) const noexcept {
+		if (position < Length()) {
+			return starts->PartitionFromPosition(position);
+		} else {
+			return starts->Partitions();
+		}
+	}
+	const T& ValueAt(Sci::Position position) const noexcept {
+		assert(position <= Length());
+		const Sci::Position partition = ElementFromPosition(position);
 		const Sci::Position startPartition = starts->PositionFromPartition(partition);
 		if (startPartition == position) {
 			return values->ValueAt(partition);
@@ -61,8 +72,8 @@ public:
 	}
 	template <typename ParamType>
 	void SetValueAt(Sci::Position position, ParamType &&value) {
-		assert(position < Length());
-		const Sci::Position partition = starts->PartitionFromPosition(position);
+		assert(position <= Length());
+		const Sci::Position partition = ElementFromPosition(position);
 		const Sci::Position startPartition = starts->PositionFromPartition(partition);
 		if (value == T()) {
 			// Setting the empty value is equivalent to deleting the position
@@ -88,7 +99,7 @@ public:
 		}
 	}
 	void InsertSpace(Sci::Position position, Sci::Position insertLength) {
-		assert(position <= Length());	// Only operation that works at end.
+		assert(position <= Length());
 		const Sci::Position partition = starts->PartitionFromPosition(position);
 		const Sci::Position startPartition = starts->PositionFromPartition(partition);
 		if (startPartition == position) {
@@ -149,10 +160,6 @@ public:
 		if (starts->Partitions() != values->Length() - 1) {
 			throw std::runtime_error("SparseVector: Partitions and values different lengths.");
 		}
-		// The final element can not be set
-		if (values->ValueAt(values->Length() - 1) != T()) {
-			throw std::runtime_error("SparseVector: Unused style at end changed.");
-		}
 #endif
 	}
 };
diff --git a/test/unit/testContractionState.cxx b/test/unit/testContractionState.cxx
index fcee90287..5fada7645 100644
--- a/test/unit/testContractionState.cxx
+++ b/test/unit/testContractionState.cxx
@@ -147,12 +147,18 @@ TEST_CASE("ContractionState") {
 
 	SECTION("SetFoldDisplayText") {
 		pcs->InsertLines(0, 4);
+		REQUIRE(5 == pcs->LinesInDoc());
 		pcs->SetFoldDisplayText(1, "abc");
 		REQUIRE(strcmp(pcs->GetFoldDisplayText(1), "abc") == 0);
 		pcs->SetFoldDisplayText(1, "def");
 		REQUIRE(strcmp(pcs->GetFoldDisplayText(1), "def") == 0);
 		pcs->SetFoldDisplayText(1, nullptr);
 		REQUIRE(static_cast<const char *>(nullptr) == pcs->GetFoldDisplayText(1));
+		// At end
+		pcs->SetFoldDisplayText(5, "xyz");
+		REQUIRE(strcmp(pcs->GetFoldDisplayText(5), "xyz") == 0);
+		pcs->DeleteLines(4, 1);
+		REQUIRE(strcmp(pcs->GetFoldDisplayText(4), "xyz") == 0);
 	}
 
 }
diff --git a/test/unit/testSparseVector.cxx b/test/unit/testSparseVector.cxx
index df7b412ce..4d3b872e1 100644
--- a/test/unit/testSparseVector.cxx
+++ b/test/unit/testSparseVector.cxx
@@ -27,7 +27,7 @@ using namespace Scintilla;
 // to simplify checks.
 static std::string Representation(const SparseVector<UniqueString> &st) {
 	std::string ret;
-	for (int i = 0;i < st.Length();i++) {
+	for (int i = 0;i <= st.Length();i++) {
 		const char *value = st.ValueAt(i).get();
 		if (value && *value)
 			ret += value;
@@ -44,6 +44,7 @@ TEST_CASE("SparseVector") {
 	SECTION("IsEmptyInitially") {
 		REQUIRE(1 == st.Elements());
 		REQUIRE(0 == st.Length());
+		REQUIRE("-" == Representation(st));
 		st.Check();
 	}
 
@@ -60,7 +61,7 @@ TEST_CASE("SparseVector") {
 		st.InsertSpace(0, 5);
 		st.SetValueAt(3, UniqueStringCopy("3"));
 		REQUIRE(2 == st.Elements());
-		REQUIRE("---3-" == Representation(st));
+		REQUIRE("---3--" == Representation(st));
 		st.Check();
 	}
 
@@ -74,7 +75,7 @@ TEST_CASE("SparseVector") {
 		st.DeletePosition(3);
 		REQUIRE(1 == st.Elements());
 		REQUIRE(4 == st.Length());
-		REQUIRE("----" == Representation(st));
+		REQUIRE("-----" == Representation(st));
 		st.Check();
 	}
 
@@ -83,7 +84,13 @@ TEST_CASE("SparseVector") {
 		st.InsertSpace(0, 5);
 		st.SetValueAt(0, UniqueStringCopy("3"));
 		REQUIRE(1 == st.Elements());
-		REQUIRE("3----" == Representation(st));
+		REQUIRE("3-----" == Representation(st));
+		st.DeletePosition(0);
+		REQUIRE(1 == st.Elements());
+		REQUIRE("-----" == Representation(st));
+		st.SetValueAt(0, UniqueStringCopy("4"));
+		REQUIRE(1 == st.Elements());
+		REQUIRE("4----" == Representation(st));
 		st.DeletePosition(0);
 		REQUIRE(1 == st.Elements());
 		REQUIRE("----" == Representation(st));
@@ -101,10 +108,10 @@ TEST_CASE("SparseVector") {
 		st.InsertSpace(0, 5);
 		st.SetValueAt(0, UniqueStringCopy("3"));
 		REQUIRE(1 == st.Elements());
-		REQUIRE("3----" == Representation(st));
+		REQUIRE("3-----" == Representation(st));
 		st.InsertSpace(0, 1);
 		REQUIRE(2 == st.Elements());
-		REQUIRE("-3----" == Representation(st));
+		REQUIRE("-3-----" == Representation(st));
 		st.Check();
 	}
 
@@ -113,10 +120,10 @@ TEST_CASE("SparseVector") {
 		st.InsertSpace(0, 5);
 		st.SetValueAt(1, UniqueStringCopy("1"));
 		REQUIRE(2 == st.Elements());
-		REQUIRE("-1---" == Representation(st));
+		REQUIRE("-1----" == Representation(st));
 		st.InsertSpace(1, 1);
 		REQUIRE(2 == st.Elements());
-		REQUIRE("--1---" == Representation(st));
+		REQUIRE("--1----" == Representation(st));
 		st.Check();
 	}
 
@@ -125,10 +132,10 @@ TEST_CASE("SparseVector") {
 		st.InsertSpace(0, 5);
 		st.SetValueAt(1, UniqueStringCopy("9"));
 		REQUIRE(2 == st.Elements());
-		REQUIRE("-9---" == Representation(st));
+		REQUIRE("-9----" == Representation(st));
 		st.InsertSpace(0, 1);
 		REQUIRE(2 == st.Elements());
-		REQUIRE("--9---" == Representation(st));
+		REQUIRE("--9----" == Representation(st));
 		// Initial st has allocation of 9 values so this should cause reallocation
 		const std::string letters("ABCDEFGHIJKLMNOP");	// 16 letters
 		for (const char letter : letters) {
@@ -136,7 +143,7 @@ TEST_CASE("SparseVector") {
 			st.InsertSpace(0, 1);
 			st.SetValueAt(1, UniqueStringCopy(sLetter));
 		}
-		REQUIRE("-PONMLKJIHGFEDCBA-9---" == Representation(st));
+		REQUIRE("-PONMLKJIHGFEDCBA-9----" == Representation(st));
 		st.Check();
 	}
 
@@ -145,10 +152,16 @@ TEST_CASE("SparseVector") {
 		st.InsertSpace(0, 5);
 		st.SetValueAt(4, UniqueStringCopy("5"));
 		REQUIRE(2 == st.Elements());
-		REQUIRE("----5" == Representation(st));
+		REQUIRE("----5-" == Representation(st));
+		st.SetValueAt(5, UniqueStringCopy("6"));
+		REQUIRE(2 == st.Elements());
+		REQUIRE("----56" == Representation(st));
 		st.DeletePosition(4);
 		REQUIRE(1 == st.Elements());
-		REQUIRE("----" == Representation(st));
+		REQUIRE("----6" == Representation(st));
+		st.SetValueAt(4, UniqueStringCopy("7"));
+		REQUIRE(1 == st.Elements());
+		REQUIRE("----7" == Representation(st));
 		st.Check();
 	}
 
@@ -157,10 +170,10 @@ TEST_CASE("SparseVector") {
 		st.InsertSpace(0, 5);
 		st.SetValueAt(4, UniqueStringCopy("5"));
 		REQUIRE(2 == st.Elements());
-		REQUIRE("----5" == Representation(st));
+		REQUIRE("----5-" == Representation(st));
 		st.SetValueAt(4, nullptr);
 		REQUIRE(1 == st.Elements());
-		REQUIRE("-----" == Representation(st));
+		REQUIRE("------" == Representation(st));
 		st.Check();
 	}
 
@@ -168,16 +181,16 @@ TEST_CASE("SparseVector") {
 		REQUIRE(1 == st.Elements());
 		st.InsertSpace(0, 1);
 		st.SetValueAt(0, UniqueStringCopy("1"));
-		REQUIRE("1" == Representation(st));
+		REQUIRE("1-" == Representation(st));
 		REQUIRE(1 == st.Elements());
 		st.InsertSpace(1, 1);
 		st.SetValueAt(1, UniqueStringCopy("2"));
-		REQUIRE("12" == Representation(st));
+		REQUIRE("12-" == Representation(st));
 		st.DeletePosition(0);
-		REQUIRE("2" == Representation(st));
+		REQUIRE("2-" == Representation(st));
 		REQUIRE(1 == st.Elements());
 		st.DeletePosition(0);
-		REQUIRE("" == Representation(st));
+		REQUIRE("-" == Representation(st));
 	}
 
 	SECTION("DeleteAll") {
@@ -188,10 +201,22 @@ TEST_CASE("SparseVector") {
 		st.SetValueAt(4, UniqueStringCopy("4"));
 		st.SetValueAt(3, UniqueStringCopy("3"));
 		REQUIRE(5 == st.Elements());
-		REQUIRE("---34--7-9" == Representation(st));
+		REQUIRE("---34--7-9-" == Representation(st));
 		st.Check();
 	}
 
+	SECTION("DeleteStarting") {
+		REQUIRE(1 == st.Elements());
+		st.InsertSpace(0, 2);
+		st.SetValueAt(0, UniqueStringCopy("1"));
+		st.SetValueAt(1, UniqueStringCopy("2"));
+		REQUIRE("12-" == Representation(st));
+		st.DeletePosition(0);
+		REQUIRE("2-" == Representation(st));
+		st.DeletePosition(0);
+		REQUIRE("-" == Representation(st));
+	}
+
 }
 
 TEST_CASE("SparseTextInt") {