public override void PostWalk(CallExpression node)
{
if (IsInRange(node) && node.Target != null)
{
// For call nodes, we don't want either the call nor the called function to show up,
// but if it is a method, then we do want to show the object on which it is called.
// For example, given A.B.C(42), we want A.B to show. By the time we get here, we
// already have A.B.C in the list, so we need to remove it and reinstate A.B, which
// will be stored as a value in the dictionary with A.B.C as key.
Expression oldNode;
_expressions.TryGetValue(node.Target, out oldNode);
_expressions.Remove(node.Target);
if (oldNode != null)
{
_expressions.Add(oldNode, null);
}
// Hardcode some commonly used side-effect-free builtins to show even in calls.
var name = node.Target as NameExpression;
if (name != null && DetectSideEffectsWalker.IsSideEffectFreeCall(name.Name) && node.Args.All(arg => IsValidTarget(arg.Expression)))
{
_expressions.Add(node, null);
}
}
}
private bool IsValidTarget(Node node)
{
if (node == null || node is ConstantExpression || node is NameExpression)
{
return(true);
}
var expr = node as Expression;
if (expr != null && _expressions.ContainsKey(expr))
{
return(true);
}
var walker = new DetectSideEffectsWalker();
node.Walk(walker);
return(!walker.HasSideEffects);
}
private Response ExpressionForDataTip(AP.ExpressionForDataTipRequest request) {
var pyEntry = _projectFiles[request.fileId] as IPythonProjectEntry;
string dataTipExpression = null;
var options = new CodeFormattingOptions() {
UseVerbatimImage = false
};
if (pyEntry != null && pyEntry.Analysis != null) {
var ast = pyEntry.Analysis.GetAstFromText(request.expr, new SourceLocation(request.index, request.line, request.column));
var expr = Statement.GetExpression(ast.Body);
if (ast != null) {
var walker = new DetectSideEffectsWalker();
ast.Walk(walker);
if (!walker.HasSideEffects) {
dataTipExpression = expr?.ToCodeString(ast, new CodeFormattingOptions() { UseVerbatimImage = false });
}
}
}
return new AP.ExpressionForDataTipResponse() {
expression = dataTipExpression
};
}
private bool IsValidTarget(Node node) {
if (node == null || node is ConstantExpression || node is NameExpression) {
return true;
}
var expr = node as Expression;
if (expr != null && _expressions.ContainsKey(expr)) {
return true;
}
var walker = new DetectSideEffectsWalker();
node.Walk(walker);
return !walker.HasSideEffects;
}