/// <summary>
/// Starting at the given node, gets a list of <see cref="Expression"/>s that include and follow this node's references.
/// </summary>
internal static IEnumerable<Expression> FlattenExpressions(VisualProgram context, StatementReference firstStatement) {
var list = new List<Expression>();
var currentNode = firstStatement.ResolveNode(context);
while (currentNode is VisualStatement currentStatement) {
list.Add(currentStatement.CreateExpression(context));
currentNode = currentStatement.GetCompilerNextStatement(context)?.ResolveNode(context);
}
return list;
}
/// <summary>
/// Finds the next node in common in the two branches. Can be used to help optimise the generation of branching flow statements
/// such as if conditions, etc. Returns null if there is no common node.
/// </summary>
internal static StatementReference? FindNextSharedNode(VisualProgram context, StatementReference branch1, StatementReference branch2) {
// Early return if either branch doesn't have any attached nodes - there cannot be a shared node if there are no nodes.
if (!branch1.HasValue || !branch2.HasValue) return null;
// Get a flat list of all Guids in the first branch
var nodesIn1 = new List<Guid>();
StatementReference? currentRef = branch1;
while (currentRef.HasValue && currentRef.Value.HasValue) {
nodesIn1.Add(currentRef?.nodeId!.Value);
// Note that we use GetNextStatement here instead of NextStatement since, if it is a branch, we want the next shared statement of that branch
currentRef = (currentRef?.ResolveNode(context) as VisualStatement)?.GetCompilerNextStatement(context);
}
// Search the second branch until we find the first occurance of the same node in the first branch
currentRef = branch2;
while (currentRef.HasValue && currentRef.Value.HasValue) {
if (nodesIn1.Contains(currentRef.Value.nodeId!.Value))
return currentRef.Value;
currentRef = (currentRef?.ResolveNode(context) as VisualStatement)?.GetCompilerNextStatement(context);
}
return null;
}