private static bool IsValidExtraction(IExtractMethodInput input, SelectionTarget target)
{
if (target.Parents[target.Parents.Length - 1] is ClassDefinition)
{
input.CannotExtract("Cannot extract statements from a class definition");
return(false);
}
string invalidExtractMsg = target.InvalidExtractionMessage;
if (invalidExtractMsg != null)
{
input.CannotExtract(invalidExtractMsg);
return(false);
}
var breakContinueWalker = new ContinueBreakWalker();
target.Walk(breakContinueWalker);
if (breakContinueWalker.ContainsBreak)
{
input.CannotExtract("The selection contains a \"break\" statement, but not the enclosing loop");
return(false);
}
else if (breakContinueWalker.ContainsContinue)
{
input.CannotExtract("The selection contains a \"continue\" statement, but not the enclosing loop");
return(false);
}
var yieldWalker = new YieldWalker();
target.Walk(yieldWalker);
if (yieldWalker.ContainsYield)
{
input.CannotExtract("Cannot extract code containing \"yield\" expression");
return(false);
}
var importStarWalker = new ImportStarWalker();
target.Walk(importStarWalker);
if (importStarWalker.ContainsImportStar)
{
input.CannotExtract("Cannot extract method containing from ... import * statement");
return(false);
}
var returnWalker = new ReturnWalker();
target.Walk(returnWalker);
if (returnWalker.ContainsReturn && !returnWalker.Returns)
{
input.CannotExtract("When the selection contains a return statement, all code paths must be terminated by a return statement too.");
return(false);
}
target.ContainsReturn = returnWalker.ContainsReturn;
return(true);
}
public async Task <bool> ExtractMethod(IExtractMethodInput input)
{
var analyzer = _view.GetAnalyzerAtCaret(_serviceProvider);
if (analyzer == null)
{
return(false);
}
var buffer = _view.GetPythonBufferAtCaret();
var snapshot = buffer.CurrentSnapshot;
var projectFile = _view.GetAnalysisAtCaret(_serviceProvider);
if (projectFile == null)
{
return(false);
}
// extract once to validate the selection
var extractInfo = await analyzer.ExtractMethodAsync(
projectFile,
buffer,
_view,
"method_name",
null,
null
);
if (extractInfo == null)
{
return(false);
}
var extract = extractInfo.Data;
if (extract.cannotExtractMsg != null)
{
input.CannotExtract(extract.cannotExtractMsg);
return(false);
}
if (extract.wasExpanded && !input.ShouldExpandSelection())
{
return(false);
}
if (extract.startIndex != null && extract.endIndex != null)
{
var selectionSpan = _view.BufferGraph.MapUpToBuffer(
new SnapshotSpan(
snapshot,
Span.FromBounds(extract.startIndex.Value, extract.endIndex.Value)
),
SpanTrackingMode.EdgeInclusive,
_view.TextBuffer
);
foreach (var span in selectionSpan)
{
_view.Selection.Select(span, false);
break;
}
}
var info = input.GetExtractionInfo(new ExtractedMethodCreator(analyzer, projectFile, _view, buffer, extract));
if (info == null)
{
// user cancelled extract method
return(false);
}
// extract again to get the final result...
extractInfo = await analyzer.ExtractMethodAsync(
projectFile,
buffer,
_view,
info.Name,
info.Parameters,
info.TargetScope?.Scope.id
);
if (extractInfo == null)
{
return(false);
}
VsProjectAnalyzer.ApplyChanges(
extractInfo.Data.changes,
buffer,
extractInfo.GetTracker(extractInfo.Data.version)
);
return(true);
}
public async Task <bool> ExtractMethod(IExtractMethodInput input)
{
var buffer = _view.GetPythonBufferAtCaret();
var bi = _services.GetBufferInfo(buffer);
var entry = bi?.AnalysisEntry;
if (entry?.Analyzer == null)
{
return(false);
}
var snapshot = buffer.CurrentSnapshot;
// extract once to validate the selection
var extract = await entry.Analyzer.ExtractMethodAsync(
bi,
_view,
"method_name",
null,
null
);
if (extract == null)
{
return(false);
}
if (extract.cannotExtractMsg != null)
{
input.CannotExtract(extract.cannotExtractMsg);
return(false);
}
if (extract.wasExpanded && !input.ShouldExpandSelection())
{
return(false);
}
if (extract.startLine > 0 && extract.endLine > 0)
{
var selectionSpan = _view.BufferGraph.MapUpToBuffer(
new SourceSpan(
new SourceLocation(extract.startLine, extract.startCol),
new SourceLocation(extract.endLine, extract.endCol)
).ToSnapshotSpan(snapshot),
SpanTrackingMode.EdgeInclusive,
_view.TextBuffer
);
foreach (var span in selectionSpan)
{
_view.Selection.Select(span, false);
break;
}
}
var info = input.GetExtractionInfo(new ExtractedMethodCreator(bi, _view, extract));
if (info == null)
{
// user cancelled extract method
return(false);
}
// extract again to get the final result...
extract = await entry.Analyzer.ExtractMethodAsync(
bi,
_view,
info.Name,
info.Parameters,
info.TargetScope?.Scope.id
);
if (extract == null)
{
return(false);
}
VsProjectAnalyzer.ApplyChanges(
extract.changes,
buffer,
bi.LocationTracker,
extract.version
);
return(true);
}
public bool ExtractMethod(IExtractMethodInput input) {
// tighten up the selection so that we don't expand into any enclosing nodes because we overlap w/ their white space...
var selectionStart = _view.Selection.Start.Position;
while (selectionStart.Position < _view.TextBuffer.CurrentSnapshot.Length && Char.IsWhiteSpace(selectionStart.GetChar())) {
selectionStart += 1;
}
var selectionEnd = _view.Selection.End.Position;
if (selectionEnd.Position == _view.TextBuffer.CurrentSnapshot.Length) {
selectionEnd -= 1;
}
while (selectionEnd.Position >= 0 && Char.IsWhiteSpace(selectionEnd.GetChar())) {
selectionEnd -= 1;
}
var walker = new EnclosingNodeWalker(_ast, selectionStart, selectionEnd);
_ast.Walk(walker);
Debug.Assert(walker.Target != null);
if (walker.Target == null) {
return false;
}
// expand the selection if we aren't currently covering a full expression/statement
if (!walker.Target.IsValidSelection ||
(WasSelectionExpanded(walker.Target, selectionStart, selectionEnd) && !input.ShouldExpandSelection())) {
return false;
}
_view.Selection.Select(
new SnapshotSpan(
_view.TextBuffer.CurrentSnapshot,
Span.FromBounds(
walker.Target.StartIncludingIndentation,
walker.Target.End
)
),
false
);
// check for things we cannot handle
if (!IsValidExtraction(input, walker.Target)) {
return false;
}
// get the variables which are read by the selected statement(s)
var varCollector = new InnerVariableWalker(_ast);
walker.Target.Walk(varCollector);
// Walk the target to understand flow control and definite assignment to further understand
// what we need to flow in. For example if a variable is assigned to both in the un-extracted
// and extracted code but it's definitely assigned in the extracted code then we don't need
// to flow the variable in.
// Run flow checker, first on any nested scopes...
foreach (ScopeStatement scope in varCollector._scopes) {
FlowChecker.Check(scope);
}
// then on our extracted code
var parent = walker.Target.Parents[walker.Target.Parents.Length - 1];
HashSet<PythonVariable> readBeforeInit;
FlowChecker extractedChecker = null;
if (parent.ScopeVariables != null) {
extractedChecker = new FlowChecker(parent);
walker.Target.Walk(extractedChecker);
readBeforeInit = extractedChecker.ReadBeforeInitializedVariables;
} else {
readBeforeInit = new HashSet<PythonVariable>();
}
// then on code which follows our extracted body
var afterStmts = walker.Target.GetStatementsAfter(_ast);
HashSet<PythonVariable> readByFollowingCodeBeforeInit = null;
var parentNode = walker.Target.Parents[walker.Target.Parents.Length - 1];
var outputVars = new HashSet<PythonVariable>();
if (parentNode.ScopeVariables != null) {
var checker = new FlowChecker(parentNode);
foreach (var afterStmt in afterStmts) {
afterStmt.Walk(checker);
}
readByFollowingCodeBeforeInit = checker.ReadBeforeInitializedVariables;
foreach (var variable in varCollector._allWrittenVariables) {
if (variable != null && variable.Scope is PythonAst) {
// global variable assigned to in outer scope, and left with
// a valid value (not deleted) from the extracted code. We
// need to pass the value back out and assign to it in the
// global scope.
if (!checker.IsInitialized(variable) &&
extractedChecker.IsAssigned(variable)) {
outputVars.Add(variable);
}
}
}
}
// collect any nested scopes, and see if they read any free variables
var scopeCollector = new ScopeCollector();
foreach (var afterStmt in afterStmts) {
afterStmt.Walk(scopeCollector);
}
foreach (var scope in scopeCollector._scopes) {
if (scope.FreeVariables != null) {
foreach (var freeVar in scope.FreeVariables) {
if (varCollector._allWrittenVariables.Contains(freeVar)) {
// we've assigned to a variable accessed from an inner
// scope, we need to get the value of the variable back out.
outputVars.Add(freeVar);
}
}
}
}
// discover any variables which are consumed and need to be available as outputs...
var outputCollector = new OuterVariableWalker(_ast, walker.Target, varCollector, readBeforeInit, readByFollowingCodeBeforeInit, outputVars);
_ast.Walk(outputCollector);
if (outputCollector._outputVars.Count > 0 &&
walker.Target.ContainsReturn) {
input.CannotExtract("Cannot extract method that assigns to variables and returns");
return false;
}
var creator = new ExtractedMethodCreator(
_ast,
walker.Target.Parents,
outputCollector._inputVars,
outputCollector._outputVars,
walker.Target,
_view.Options.GetIndentSize(),
!_view.Options.IsConvertTabsToSpacesEnabled(),
_view.Options.GetNewLineCharacter()
);
var info = input.GetExtractionInfo(creator);
if (info == null) {
// user cancelled extract method
return false;
}
// get the new method body...
var newMethod = creator.GetExtractionResult(info);
// generate the call site.
using (var edit = _view.TextBuffer.CreateEdit()) {
// delete the selected code
int start = _view.Selection.Start.Position;
edit.Delete(Span.FromBounds(_view.Selection.Start.Position, _view.Selection.End.Position));
// insert the newly generated method
edit.Insert(walker.Target.InsertLocations[info.TargetScope], newMethod.Method);
// insert the call to the new method
edit.Insert(start, newMethod.Call);
edit.Apply();
}
return true;
}
private static bool IsValidExtraction(IExtractMethodInput input, SelectionTarget target) {
if (target.Parents[target.Parents.Length - 1] is ClassDefinition) {
input.CannotExtract("Cannot extract statements from a class definition");
return false;
}
string invalidExtractMsg = target.InvalidExtractionMessage;
if (invalidExtractMsg != null) {
input.CannotExtract(invalidExtractMsg);
return false;
}
var breakContinueWalker = new ContinueBreakWalker();
target.Walk(breakContinueWalker);
if (breakContinueWalker.ContainsBreak) {
input.CannotExtract("The selection contains a \"break\" statement, but not the enclosing loop");
return false;
} else if (breakContinueWalker.ContainsContinue) {
input.CannotExtract("The selection contains a \"continue\" statement, but not the enclosing loop");
return false;
}
var yieldWalker = new YieldWalker();
target.Walk(yieldWalker);
if (yieldWalker.ContainsYield) {
input.CannotExtract("Cannot extract code containing \"yield\" expression");
return false;
}
var importStarWalker = new ImportStarWalker();
target.Walk(importStarWalker);
if (importStarWalker.ContainsImportStar) {
input.CannotExtract("Cannot extract method containing from ... import * statement");
return false;
}
var returnWalker = new ReturnWalker();
target.Walk(returnWalker);
if (returnWalker.ContainsReturn && !returnWalker.Returns) {
input.CannotExtract("When the selection contains a return statement, all code paths must be terminated by a return statement too.");
return false;
}
target.ContainsReturn = returnWalker.ContainsReturn;
return true;
}
public async Task <bool> ExtractMethod(IExtractMethodInput input)
{
var analyzer = _view.GetAnalyzer(_serviceProvider);
var projectFile = _view.TextBuffer.GetAnalysisEntry();
// extract once to validate the selection
var extractInfo = await analyzer.ExtractMethodAsync(
projectFile,
_view.TextBuffer,
_view,
"method_name",
null,
null
);
if (extractInfo == null)
{
return(false);
}
var extract = extractInfo.Data;
if (extract.cannotExtractMsg != null)
{
input.CannotExtract(extract.cannotExtractMsg);
return(false);
}
if (extract.wasExpanded && !input.ShouldExpandSelection())
{
return(false);
}
if (extract.startIndex != null && extract.endIndex != null)
{
_view.Selection.Select(
new SnapshotSpan(
_view.TextBuffer.CurrentSnapshot,
Span.FromBounds(extract.startIndex.Value, extract.endIndex.Value)
),
false
);
}
var info = input.GetExtractionInfo(new ExtractedMethodCreator(analyzer, projectFile, _view, extract));
if (info == null)
{
// user cancelled extract method
return(false);
}
// extract again to get the final result...
extractInfo = await analyzer.ExtractMethodAsync(
projectFile,
_view.TextBuffer,
_view,
info.Name,
info.Parameters,
info.TargetScope?.Scope.id
);
if (extractInfo == null)
{
return(false);
}
VsProjectAnalyzer.ApplyChanges(
extractInfo.Data.changes,
_view.TextBuffer,
extractInfo.GetTracker(extractInfo.Data.version)
);
return(true);
}
public bool ExtractMethod(IExtractMethodInput input)
{
// tighten up the selection so that we don't expand into any enclosing nodes because we overlap w/ their white space...
var selectionStart = _view.Selection.Start.Position;
while (selectionStart.Position < _view.TextBuffer.CurrentSnapshot.Length && Char.IsWhiteSpace(selectionStart.GetChar()))
{
selectionStart += 1;
}
var selectionEnd = _view.Selection.End.Position;
if (selectionEnd.Position == _view.TextBuffer.CurrentSnapshot.Length)
{
selectionEnd -= 1;
}
while (selectionEnd.Position >= 0 && Char.IsWhiteSpace(selectionEnd.GetChar()))
{
selectionEnd -= 1;
}
var walker = new EnclosingNodeWalker(_ast, selectionStart, selectionEnd);
_ast.Walk(walker);
Debug.Assert(walker.Target != null);
if (walker.Target == null)
{
return(false);
}
// expand the selection if we aren't currently covering a full expression/statement
if (!walker.Target.IsValidSelection ||
(WasSelectionExpanded(walker.Target, selectionStart, selectionEnd) && !input.ShouldExpandSelection()))
{
return(false);
}
_view.Selection.Select(
new SnapshotSpan(
_view.TextBuffer.CurrentSnapshot,
Span.FromBounds(
walker.Target.StartIncludingIndentation,
walker.Target.End
)
),
false
);
// check for things we cannot handle
if (!IsValidExtraction(input, walker.Target))
{
return(false);
}
// get the variables which are read by the selected statement(s)
var varCollector = new InnerVariableWalker(_ast);
walker.Target.Walk(varCollector);
// Walk the target to understand flow control and definite assignment to further understand
// what we need to flow in. For example if a variable is assigned to both in the un-extracted
// and extracted code but it's definitely assigned in the extracted code then we don't need
// to flow the variable in.
// Run flow checker, first on any nested scopes...
foreach (ScopeStatement scope in varCollector._scopes)
{
FlowChecker.Check(scope);
}
// then on our extracted code
var parent = walker.Target.Parents[walker.Target.Parents.Length - 1];
HashSet <PythonVariable> readBeforeInit;
FlowChecker extractedChecker = null;
if (parent.ScopeVariables != null)
{
extractedChecker = new FlowChecker(parent);
walker.Target.Walk(extractedChecker);
readBeforeInit = extractedChecker.ReadBeforeInitializedVariables;
}
else
{
readBeforeInit = new HashSet <PythonVariable>();
}
// then on code which follows our extracted body
var afterStmts = walker.Target.GetStatementsAfter(_ast);
HashSet <PythonVariable> readByFollowingCodeBeforeInit = null;
var parentNode = walker.Target.Parents[walker.Target.Parents.Length - 1];
var outputVars = new HashSet <PythonVariable>();
if (parentNode.ScopeVariables != null)
{
var checker = new FlowChecker(parentNode);
foreach (var afterStmt in afterStmts)
{
afterStmt.Walk(checker);
}
readByFollowingCodeBeforeInit = checker.ReadBeforeInitializedVariables;
foreach (var variable in varCollector._allWrittenVariables)
{
if (variable != null && variable.Scope is PythonAst)
{
// global variable assigned to in outer scope, and left with
// a valid value (not deleted) from the extracted code. We
// need to pass the value back out and assign to it in the
// global scope.
if (!checker.IsInitialized(variable) &&
extractedChecker.IsAssigned(variable))
{
outputVars.Add(variable);
}
}
}
}
// collect any nested scopes, and see if they read any free variables
var scopeCollector = new ScopeCollector();
foreach (var afterStmt in afterStmts)
{
afterStmt.Walk(scopeCollector);
}
foreach (var scope in scopeCollector._scopes)
{
if (scope.FreeVariables != null)
{
foreach (var freeVar in scope.FreeVariables)
{
if (varCollector._allWrittenVariables.Contains(freeVar))
{
// we've assigned to a variable accessed from an inner
// scope, we need to get the value of the variable back out.
outputVars.Add(freeVar);
}
}
}
}
// discover any variables which are consumed and need to be available as outputs...
var outputCollector = new OuterVariableWalker(_ast, walker.Target, varCollector, readBeforeInit, readByFollowingCodeBeforeInit, outputVars);
_ast.Walk(outputCollector);
if (outputCollector._outputVars.Count > 0 &&
walker.Target.ContainsReturn)
{
input.CannotExtract("Cannot extract method that assigns to variables and returns");
return(false);
}
var creator = new ExtractedMethodCreator(
_ast,
walker.Target.Parents,
outputCollector._inputVars,
outputCollector._outputVars,
walker.Target,
_view.Options.GetIndentSize(),
!_view.Options.IsConvertTabsToSpacesEnabled(),
_view.Options.GetNewLineCharacter()
);
var info = input.GetExtractionInfo(creator);
if (info == null)
{
// user cancelled extract method
return(false);
}
// get the new method body...
var newMethod = creator.GetExtractionResult(info);
// generate the call site.
using (var edit = _view.TextBuffer.CreateEdit()) {
// delete the selected code
int start = _view.Selection.Start.Position;
edit.Delete(Span.FromBounds(_view.Selection.Start.Position, _view.Selection.End.Position));
// insert the newly generated method
edit.Insert(walker.Target.InsertLocations[info.TargetScope], newMethod.Method);
// insert the call to the new method
edit.Insert(start, newMethod.Call);
edit.Apply();
}
return(true);
}
public async Task<bool> ExtractMethod(IExtractMethodInput input) {
var analyzer = _view.GetAnalyzerAtCaret(_serviceProvider);
if (analyzer == null) {
return false;
}
var buffer = _view.GetPythonBufferAtCaret();
var snapshot = buffer.CurrentSnapshot;
var projectFile = _view.GetAnalysisAtCaret(_serviceProvider);
if (projectFile == null) {
return false;
}
// extract once to validate the selection
var extractInfo = await analyzer.ExtractMethodAsync(
projectFile,
buffer,
_view,
"method_name",
null,
null
);
if (extractInfo == null) {
return false;
}
var extract = extractInfo.Data;
if (extract.cannotExtractMsg != null) {
input.CannotExtract(extract.cannotExtractMsg);
return false;
}
if (extract.wasExpanded && !input.ShouldExpandSelection()) {
return false;
}
if (extract.startIndex != null && extract.endIndex != null) {
var selectionSpan = _view.BufferGraph.MapUpToBuffer(
new SnapshotSpan(
snapshot,
Span.FromBounds(extract.startIndex.Value, extract.endIndex.Value)
),
SpanTrackingMode.EdgeInclusive,
_view.TextBuffer
);
foreach (var span in selectionSpan) {
_view.Selection.Select(span, false);
break;
}
}
var info = input.GetExtractionInfo(new ExtractedMethodCreator(analyzer, projectFile, _view, buffer, extract));
if (info == null) {
// user cancelled extract method
return false;
}
// extract again to get the final result...
extractInfo = await analyzer.ExtractMethodAsync(
projectFile,
buffer,
_view,
info.Name,
info.Parameters,
info.TargetScope?.Scope.id
);
if (extractInfo == null) {
return false;
}
VsProjectAnalyzer.ApplyChanges(
extractInfo.Data.changes,
buffer,
extractInfo.GetTracker(extractInfo.Data.version)
);
return true;
}