/// <summary>
/// Map variable to shorter name.
/// </summary>
/// <param name="astNode"></param>
/// <param name="shortNameMap"></param>
/// <param name="nameGenerator"></param>
private static void ShortNameMapping(
ProtoCore.Core core,
AssociativeNode astNode,
Dictionary <string, string> shortNameMap,
ShortNameGenerator nameGenerator,
HashSet <string> mappedVariables)
{
Action <IdentifierNode> func = n =>
{
string shortName;
if (shortNameMap.TryGetValue(n.Value, out shortName))
{
if (shortName == string.Empty)
{
shortName = nameGenerator.GetNextName();
while (mappedVariables.Contains(shortName))
{
shortName = nameGenerator.GetNextName();
}
shortNameMap[n.Value] = shortName;
}
n.Value = n.Name = shortName;
}
};
IdentifierVisitor visitor = new IdentifierVisitor(func, core);
astNode.Accept(visitor);
}
/// <summary>
/// Compile a set of nodes to ASTs.
///
/// Note:
/// 1. Nodes should be a clique with regarding to convertibility and
/// selection state. That is, these nodes can be safely to be
/// converted into a single code block node. It shouldn't have
/// unconvertible or unselected node on any path (if there is) that
/// connects any two of these nodes, otherwise there will be
/// circular references between unconvertible/unselected node and
/// code block node.
///
/// To split arbitary node set into cliques, use
/// NodeToCodeUtils.GetCliques().
///
/// 2. WorkspaceNodes are all nodes in current workspace. We need the
/// whole graph so that each to-be-converted node will have correct
/// order in the final code block node.
/// </summary>
/// <param name="core">Library core</param>
/// <param name="astBuilder">Ast builder</param>
/// <param name="workspaceNodes">The whole workspace nodes</param>
/// <param name="nodes">Selected node that can be converted to a single code block node</param>
/// <returns></returns>
public static NodeToCodeResult NodeToCode(
ProtoCore.Core core,
AstBuilder astBuilder,
IEnumerable <NodeModel> workspaceNodes,
IEnumerable <NodeModel> nodes)
{
// The basic worflow is:
// 1. Compile each node to get its cde in AST format
//
// 2. Variable numbering to avoid confliction. For example, two
// code block nodes both have assignment "y = x", we need to
// rename "y" to "y1" and "y2" respectively.
//
// 3. Variable remapping. For example, code block node
// "x = 1" connects to "a = b", where the second code block
// node will have initialization "b = x_guid" where "x_guid"
// is because of variable mappining in the first code block
// node. We should restore it to its original name.
//
// Note in step 2 we may rename "x" to "xn".
//
// 4. Generate short name for long name variables. Typically they
// are from output ports from other nodes.
//
// 5. Do constant progation to optimize the generated code.
#region Step 1 AST compilation
var sortedGraph = AstBuilder.TopologicalSortForGraph(workspaceNodes);
var sortedNodes = sortedGraph.Where(nodes.Contains);
var allAstNodes = astBuilder.CompileToAstNodes(sortedNodes, AstBuilder.CompilationContext.NodeToCode, false);
#endregion
#region Step 2 Varialbe numbering
// External inputs will be in input map
// Internal non-cbn will be input map & output map
// Internal cbn will be in renaming map and output map
// Map from mapped variable to its original name. These variables
// are from code block nodes that in the selection.
Dictionary <string, string> renamingMap = null;;
// Input variable to renamed input variable map
Dictionary <string, string> inputMap = null;
// Output variable to renamed output variable map
Dictionary <string, string> outputMap = null;
// Collect all inputs/outputs/candidate renaming variables
GetInputOutputMap(nodes, out inputMap, out outputMap, out renamingMap);
// Variable numbering map. Value field indicates current current
// numbering value of the variable. For example, there are variables
// t1, t2, ... tn and the ID of variable t's NumberingState is n.
var numberingMap = new Dictionary <string, NumberingState>();
// In this step, we'll renumber all variables that going to be in
// the same code block node. That is,
//
// "x = 1; y = x;" and
// "x = 2; y = x;"
//
// Will be renumbered to
//
// "x1 = 1; y1 = x1;" and
// "x2 = 2; y2 = x2;"
var mappedVariables = new HashSet <string>();
foreach (var t in allAstNodes)
{
// Reset variable numbering map
foreach (var p in numberingMap)
{
p.Value.IsNewSession = true;
}
foreach (var astNode in t.Item2)
{
VariableNumbering(core, astNode, t.Item1, numberingMap, renamingMap, inputMap, outputMap, mappedVariables);
}
}
renamingMap = renamingMap.Where(p => !p.Key.Contains("%"))
.ToDictionary(p => p.Key, p => p.Value);
#endregion
#region Step 3 Variable remapping
foreach (var ts in allAstNodes)
{
foreach (var astNode in ts.Item2)
{
VariableRemapping(core, astNode, renamingMap, outputMap, mappedVariables);
}
}
#endregion
#region Step 4 Generate short name
var nameGenerator = new ShortNameGenerator();
// temporary variables are double mapped.
foreach (var key in outputMap.Keys.ToList())
{
if (key.StartsWith(Constants.kTempVarForNonAssignment) &&
outputMap[key].StartsWith(Constants.kTempVarForNonAssignment))
{
string shortName = nameGenerator.GetNextName();
while (mappedVariables.Contains(shortName))
{
shortName = nameGenerator.GetNextName();
}
var tempVar = outputMap[key];
outputMap[key] = shortName;
outputMap[tempVar] = shortName;
mappedVariables.Add(shortName);
}
}
foreach (var ts in allAstNodes)
{
foreach (var astNode in ts.Item2)
{
ShortNameMapping(core, astNode, inputMap, nameGenerator, mappedVariables);
foreach (var kvp in inputMap)
{
if (kvp.Value != String.Empty && outputMap.ContainsKey(kvp.Key))
{
outputMap[kvp.Key] = kvp.Value;
}
}
ShortNameMapping(core, astNode, outputMap, nameGenerator, mappedVariables);
}
}
#endregion
var result = new NodeToCodeResult(allAstNodes.SelectMany(x => x.Item2), inputMap, outputMap);
return(result);
}
