Implemented 'exists(object_model_path)' in expression evaluater

2 files changed, 33 insertions, 5 deletions

diff --git a/src/ObjectModel/ObjectModel.cpp b/src/ObjectModel/ObjectModel.cpp
index 6959ccd6..ecdb7009 100644
--- a/src/ObjectModel/ObjectModel.cpp
+++ b/src/ObjectModel/ObjectModel.cpp
@@ -269,7 +269,7 @@ ObjectModel::ObjectModel() noexcept
 ObjectExplorationContext::ObjectExplorationContext(bool wal, const char *reportFlags, unsigned int initialMaxDepth) noexcept
 	: startMillis(millis()), maxDepth(initialMaxDepth), currentDepth(0), numIndicesProvided(0), numIndicesCounted(0),
 	  line(-1), column(-1),
-	  shortForm(false), onlyLive(false), includeVerbose(false), wantArrayLength(wal), includeNulls(false), includeObsolete(false), obsoleteFieldQueried(false)
+	  shortForm(false), onlyLive(false), includeVerbose(false), wantArrayLength(wal), includeNulls(false), includeObsolete(false), obsoleteFieldQueried(false), wantExists(false)
 {
 	while (true)
 	{
@@ -311,10 +311,10 @@ ObjectExplorationContext::ObjectExplorationContext(bool wal, const char *reportF
 }
 
 // Constructor when evaluating expressions
-ObjectExplorationContext::ObjectExplorationContext(bool wal, int p_line, int p_col) noexcept
+ObjectExplorationContext::ObjectExplorationContext(bool wal, bool wex, int p_line, int p_col) noexcept
 	: startMillis(millis()), maxDepth(99), currentDepth(0), numIndicesProvided(0), numIndicesCounted(0),
 	  line(p_line), column(p_col),
-	  shortForm(false), onlyLive(false), includeVerbose(true), wantArrayLength(wal), includeNulls(false), includeObsolete(true), obsoleteFieldQueried(false)
+	  shortForm(false), onlyLive(false), includeVerbose(true), wantArrayLength(wal), includeNulls(false), includeObsolete(true), obsoleteFieldQueried(false), wantExists(wex)
 {
 }
 
@@ -852,11 +852,21 @@ ExpressionValue ObjectModel::GetObjectValue(ObjectExplorationContext& context, c
 		classDescriptor = classDescriptor->parent;			// search parent class object model too
 	}
 
+	if (context.WantExists())
+	{
+		return ExpressionValue(false);
+	}
+
 	throw context.ConstructParseException("unknown value '%s'", idString);
 }
 
 ExpressionValue ObjectModel::GetObjectValue(ObjectExplorationContext& context, const ObjectModelClassDescriptor *classDescriptor, const ExpressionValue& val, const char *idString) const
 {
+	if (*idString == 0 && context.WantExists() && val.GetType() != TypeCode::None)
+	{
+		return ExpressionValue(true);
+	}
+
 	switch (val.GetType())
 	{
 	case TypeCode::Array:
@@ -880,6 +890,10 @@ ExpressionValue ObjectModel::GetObjectValue(ObjectExplorationContext& context, c
 
 			if (context.GetLastIndex() < 0 || (size_t)context.GetLastIndex() >= val.omadVal->GetNumElements(this, context))
 			{
+				if (context.WantExists())
+				{
+					return ExpressionValue(false);
+				}
 				throw context.ConstructParseException("array index out of bounds");
 			}
 
@@ -902,6 +916,10 @@ ExpressionValue ObjectModel::GetObjectValue(ObjectExplorationContext& context, c
 		break;
 
 	case TypeCode::None:
+		if (context.WantExists())
+		{
+			return ExpressionValue(false);
+		}
 		if (*idString == 0)
 		{
 			return val;				// a null value can be compared to null
@@ -926,6 +944,10 @@ ExpressionValue ObjectModel::GetObjectValue(ObjectExplorationContext& context, c
 			{
 				break;
 			}
+			if (context.WantExists())
+			{
+				return ExpressionValue(true);
+			}
 			const auto bm = Bitmap<uint32_t>::MakeFromRaw(val.uVal);
 			return ExpressionValue((int32_t)bm.GetSetBitNumber(context.GetLastIndex()));
 		}
@@ -956,6 +978,10 @@ ExpressionValue ObjectModel::GetObjectValue(ObjectExplorationContext& context, c
 			{
 				break;
 			}
+			if (context.WantExists())
+			{
+				return ExpressionValue(true);
+			}
 			const auto bm = Bitmap<uint64_t>::MakeFromRaw(val.Get56BitValue());
 			return ExpressionValue((int32_t)bm.GetSetBitNumber(context.GetLastIndex()));
 		}
diff --git a/src/ObjectModel/ObjectModel.h b/src/ObjectModel/ObjectModel.h
index 09e58332..99404ca3 100644
--- a/src/ObjectModel/ObjectModel.h
+++ b/src/ObjectModel/ObjectModel.h
@@ -191,7 +191,7 @@ public:
 	ObjectExplorationContext(bool wal, const char *reportFlags, unsigned int initialMaxDepth) noexcept;
 
 	// Constructor used when evaluating expressions
-	ObjectExplorationContext(bool wal, int p_line, int p_col) noexcept;
+	ObjectExplorationContext(bool wal, bool wex, int p_line, int p_col) noexcept;
 
 	void SetMaxDepth(unsigned int d) noexcept { maxDepth = d; }
 	bool IncreaseDepth() noexcept { if (currentDepth < maxDepth) { ++currentDepth; return true; } return false; }
@@ -206,6 +206,7 @@ public:
 	bool ShortFormReport() const noexcept { return shortForm; }
 	bool ShouldReport(const ObjectModelEntryFlags f) const noexcept;
 	bool WantArrayLength() const noexcept { return wantArrayLength; }
+	bool WantExists() const noexcept { return wantExists; }
 	bool ShouldIncludeNulls() const noexcept { return includeNulls; }
 	uint64_t GetStartMillis() const { return startMillis; }
 
@@ -232,7 +233,8 @@ private:
 				wantArrayLength : 1,
 				includeNulls : 1,
 				includeObsolete : 1,
-				obsoleteFieldQueried : 1;
+				obsoleteFieldQueried : 1,
+				wantExists : 1;
 };
 
 // Entry to describe an array of objects or values. These must be brace-initializable into flash memory.