|
private TransformSet ( SourceSpan span, System.Linq.Expressions right, PythonOperationKind op ) : |
||
| span | SourceSpan | |
| right | System.Linq.Expressions | |
| op | PythonOperationKind | |
| Результат | ||
/// <summary>
/// WithStatement is translated to the DLR AST equivalent to
/// the following Python code snippet (from with statement spec):
///
/// mgr = (EXPR)
/// exit = mgr.__exit__ # Not calling it yet
/// value = mgr.__enter__()
/// exc = True
/// try:
/// VAR = value # Only if "as VAR" is present
/// BLOCK
/// except:
/// # The exceptional case is handled here
/// exc = False
/// if not exit(*sys.exc_info()):
/// raise
/// # The exception is swallowed if exit() returns true
/// finally:
/// # The normal and non-local-goto cases are handled here
/// if exc:
/// exit(None, None, None)
///
/// </summary>
public override MSAst.Expression Reduce()
{
// Five statements in the result...
ReadOnlyCollectionBuilder <MSAst.Expression> statements = new ReadOnlyCollectionBuilder <MSAst.Expression>(6);
ReadOnlyCollectionBuilder <MSAst.ParameterExpression> variables = new ReadOnlyCollectionBuilder <MSAst.ParameterExpression>(6);
MSAst.ParameterExpression lineUpdated = Ast.Variable(typeof(bool), "$lineUpdated_with");
variables.Add(lineUpdated);
//******************************************************************
// 1. mgr = (EXPR)
//******************************************************************
MSAst.ParameterExpression manager = Ast.Variable(typeof(object), "with_manager");
variables.Add(manager);
statements.Add(
GlobalParent.AddDebugInfo(
Ast.Assign(
manager,
_contextManager
),
new SourceSpan(Start, _header)
)
);
//******************************************************************
// 2. exit = mgr.__exit__ # Not calling it yet
//******************************************************************
MSAst.ParameterExpression exit = Ast.Variable(typeof(object), "with_exit");
variables.Add(exit);
statements.Add(
MakeAssignment(
exit,
GlobalParent.Get(
"__exit__",
manager
)
)
);
//******************************************************************
// 3. value = mgr.__enter__()
//******************************************************************
MSAst.ParameterExpression value = Ast.Variable(typeof(object), "with_value");
variables.Add(value);
statements.Add(
GlobalParent.AddDebugInfoAndVoid(
MakeAssignment(
value,
Parent.Invoke(
new CallSignature(0),
Parent.LocalContext,
GlobalParent.Get(
"__enter__",
manager
)
)
),
new SourceSpan(Start, _header)
)
);
//******************************************************************
// 4. exc = True
//******************************************************************
MSAst.ParameterExpression exc = Ast.Variable(typeof(bool), "with_exc");
variables.Add(exc);
statements.Add(
MakeAssignment(
exc,
AstUtils.Constant(true)
)
);
//******************************************************************
// 5. The final try statement:
//
// try:
// VAR = value # Only if "as VAR" is present
// BLOCK
// except:
// # The exceptional case is handled here
// exc = False
// if not exit(*sys.exc_info()):
// raise
// # The exception is swallowed if exit() returns true
// finally:
// # The normal and non-local-goto cases are handled here
// if exc:
// exit(None, None, None)
//******************************************************************
MSAst.ParameterExpression exception;
MSAst.ParameterExpression nestedFrames = Ast.Variable(typeof(List <DynamicStackFrame>), "$nestedFrames");
variables.Add(nestedFrames);
statements.Add(
// try:
AstUtils.Try(
AstUtils.Try(// try statement body
PushLineUpdated(false, lineUpdated),
_var != null ?
(MSAst.Expression)Ast.Block(
// VAR = value
_var.TransformSet(SourceSpan.None, value, PythonOperationKind.None),
// BLOCK
_body,
AstUtils.Empty()
) :
// BLOCK
(MSAst.Expression)_body // except:, // try statement location
).Catch(exception = Ast.Variable(typeof(Exception), "exception"),
// Python specific exception handling code
TryStatement.GetTracebackHeader(
this,
exception,
GlobalParent.AddDebugInfoAndVoid(
Ast.Block(
// exc = False
MakeAssignment(
exc,
AstUtils.Constant(false)
),
Ast.Assign(
nestedFrames,
Ast.Call(AstMethods.GetAndClearDynamicStackFrames)
),
// if not exit(*sys.exc_info()):
// raise
AstUtils.IfThen(
GlobalParent.Convert(
typeof(bool),
ConversionResultKind.ExplicitCast,
GlobalParent.Operation(
typeof(bool),
PythonOperationKind.IsFalse,
MakeExitCall(exit, exception)
)
),
UpdateLineUpdated(true),
Ast.Call(
AstMethods.SetDynamicStackFrames,
nestedFrames
),
Ast.Throw(
Ast.Call(
AstMethods.MakeRethrowExceptionWorker,
exception
)
)
)
),
_body.Span
)
),
Ast.Call(
AstMethods.SetDynamicStackFrames,
nestedFrames
),
PopLineUpdated(lineUpdated),
Ast.Empty()
)
// finally:
).Finally(
// if exc:
// exit(None, None, None)
AstUtils.IfThen(
exc,
GlobalParent.AddDebugInfoAndVoid(
Ast.Block(
Ast.Dynamic(
GlobalParent.PyContext.Invoke(
new CallSignature(3) // signature doesn't include function
),
typeof(object),
new MSAst.Expression[] {
Parent.LocalContext,
exit,
AstUtils.Constant(null),
AstUtils.Constant(null),
AstUtils.Constant(null)
}
),
Ast.Empty()
),
_contextManager.Span
)
)
)
);
statements.Add(AstUtils.Empty());
return(Ast.Block(variables.ToReadOnlyCollection(), statements.ToReadOnlyCollection()));
}
internal static MSAst.Expression TransformFor(ScopeStatement parent, MSAst.ParameterExpression enumerator,
Expression list, Expression left, MSAst.Expression body,
Statement else_, SourceSpan span, SourceLocation header,
MSAst.LabelTarget breakLabel, MSAst.LabelTarget continueLabel, bool isStatement) {
// enumerator, isDisposable = Dynamic(GetEnumeratorBinder, list)
MSAst.Expression init = Ast.Assign(
enumerator,
new PythonDynamicExpression1<KeyValuePair<IEnumerator, IDisposable>>(
Binders.UnaryOperationBinder(
parent.GlobalParent.PyContext,
PythonOperationKind.GetEnumeratorForIteration
),
parent.GlobalParent.CompilationMode,
AstUtils.Convert(list, typeof(object))
)
);
// while enumerator.MoveNext():
// left = enumerator.Current
// body
// else:
// else
MSAst.Expression ls = AstUtils.Loop(
parent.GlobalParent.AddDebugInfo(
Ast.Call(
Ast.Property(
enumerator,
typeof(KeyValuePair<IEnumerator, IDisposable>).GetProperty("Key")
),
typeof(IEnumerator).GetMethod("MoveNext")
),
left.Span
),
null,
Ast.Block(
left.TransformSet(
SourceSpan.None,
Ast.Call(
Ast.Property(
enumerator,
typeof(KeyValuePair<IEnumerator, IDisposable>).GetProperty("Key")
),
typeof(IEnumerator).GetProperty("Current").GetGetMethod()
),
PythonOperationKind.None
),
body,
isStatement ? UpdateLineNumber(parent.GlobalParent.IndexToLocation(list.StartIndex).Line) : AstUtils.Empty(),
AstUtils.Empty()
),
else_,
breakLabel,
continueLabel
);
return Ast.Block(
init,
Ast.TryFinally(
ls,
Ast.Call(AstMethods.ForLoopDispose, enumerator)
)
);
}
internal override MSAst.Expression TransformSet(SourceSpan span, MSAst.Expression right, PythonOperationKind op)
{
return(Value.TransformSet(span, right, op));
}
internal static MSAst.Expression TransformForStatement(AstGenerator ag, MSAst.ParameterExpression enumerator,
Expression list, Expression left, MSAst.Expression body,
Statement else_, SourceSpan span, SourceLocation header,
MSAst.LabelTarget breakLabel, MSAst.LabelTarget continueLabel) {
// enumerator = PythonOps.GetEnumeratorForIteration(list)
MSAst.Expression init = Ast.Assign(
enumerator,
ag.Operation(
typeof(IEnumerator),
PythonOperationKind.GetEnumeratorForIteration,
ag.TransformAsObject(list)
)
);
// while enumerator.MoveNext():
// left = enumerator.Current
// body
// else:
// else
MSAst.Expression ls = AstUtils.Loop(
ag.AddDebugInfo(Ast.Call(
enumerator,
typeof(IEnumerator).GetMethod("MoveNext")
), left.Span),
null,
Ast.Block(
left.TransformSet(
ag,
SourceSpan.None,
Ast.Call(
enumerator,
typeof(IEnumerator).GetProperty("Current").GetGetMethod()
),
PythonOperationKind.None
),
body,
ag.UpdateLineNumber(list.Start.Line),
AstUtils.Empty()
),
ag.Transform(else_),
breakLabel,
continueLabel
);
return Ast.Block(
init,
ls,
AstUtils.Empty()
);
}
internal static MSAst.Expression TransformFor(ScopeStatement parent, MSAst.ParameterExpression enumerator,
Expression list, Expression left, MSAst.Expression body,
Statement else_, SourceSpan span, SourceLocation header,
MSAst.LabelTarget breakLabel, MSAst.LabelTarget continueLabel, bool isStatement)
{
// enumerator, isDisposable = Dynamic(GetEnumeratorBinder, list)
MSAst.Expression init = Ast.Assign(
enumerator,
new PythonDynamicExpression1 <KeyValuePair <IEnumerator, IDisposable> >(
Binders.UnaryOperationBinder(
parent.GlobalParent.PyContext,
PythonOperationKind.GetEnumeratorForIteration
),
parent.GlobalParent.CompilationMode,
AstUtils.Convert(list, typeof(object))
)
);
// while enumerator.MoveNext():
// left = enumerator.Current
// body
// else:
// else
MSAst.Expression ls = AstUtils.Loop(
parent.GlobalParent.AddDebugInfo(
Ast.Call(
Ast.Property(
enumerator,
typeof(KeyValuePair <IEnumerator, IDisposable>).GetProperty("Key")
),
typeof(IEnumerator).GetMethod("MoveNext")
),
left.Span
),
null,
Ast.Block(
left.TransformSet(
SourceSpan.None,
Ast.Call(
Ast.Property(
enumerator,
typeof(KeyValuePair <IEnumerator, IDisposable>).GetProperty("Key")
),
typeof(IEnumerator).GetProperty("Current").GetGetMethod()
),
PythonOperationKind.None
),
body,
isStatement ? UpdateLineNumber(parent.GlobalParent.IndexToLocation(list.StartIndex).Line) : AstUtils.Empty(),
AstUtils.Empty()
),
else_,
breakLabel,
continueLabel
);
return(Ast.Block(
init,
Ast.TryFinally(
ls,
Ast.Block(
Ast.Call(AstMethods.ForLoopDispose, enumerator),
Ast.Assign(enumerator, Ast.New(typeof(KeyValuePair <IEnumerator, IDisposable>)))
)
)
));
}
internal override MSAst.Expression TransformSet(SourceSpan span, MSAst.Expression right, PythonOperationKind op)
{
// if we just have a simple named multi-assignment (e.g. a, b = 1,2)
// then go ahead and step over the entire statement at once. If we have a
// more complex statement (e.g. a.b, c.d = 1, 2) then we'll step over the
// sets individually as they could be property sets the user wants to step
// into. TODO: Enable stepping of the right hand side?
bool emitIndividualSets = false;
foreach (Expression e in _items)
{
if (IsComplexAssignment(e))
{
emitIndividualSets = true;
break;
}
}
SourceSpan rightSpan = SourceSpan.None;
SourceSpan leftSpan =
(Span.Start.IsValid && span.IsValid) ?
new SourceSpan(Span.Start, span.End) :
SourceSpan.None;
SourceSpan totalSpan = SourceSpan.None;
if (emitIndividualSets)
{
rightSpan = span;
leftSpan = SourceSpan.None;
totalSpan = (Span.Start.IsValid && span.IsValid) ?
new SourceSpan(Span.Start, span.End) :
SourceSpan.None;
}
// 1. Evaluate the expression and assign the value to the temp.
MSAst.ParameterExpression right_temp = Ast.Variable(typeof(object), "unpacking");
// 2. Add the assignment "right_temp = right" into the suite/block
MSAst.Expression assignStmt1 = MakeAssignment(right_temp, right);
// 3. Call GetEnumeratorValues on the right side (stored in temp)
MSAst.Expression enumeratorValues = Expression.Convert(LightExceptions.CheckAndThrow(
Expression.Call(
emitIndividualSets ?
AstMethods.GetEnumeratorValues :
AstMethods.GetEnumeratorValuesNoComplexSets, // method
// arguments
Parent.LocalContext,
right_temp,
AstUtils.Constant(_items.Length)
)
), typeof(object[]));
// 4. Create temporary variable for the array
MSAst.ParameterExpression array_temp = Ast.Variable(typeof(object[]), "array");
// 5. Assign the value of the method call (mce) into the array temp
// And add the assignment "array_temp = Ops.GetEnumeratorValues(...)" into the block
MSAst.Expression assignStmt2 = MakeAssignment(
array_temp,
enumeratorValues,
rightSpan
);
ReadOnlyCollectionBuilder <MSAst.Expression> sets = new ReadOnlyCollectionBuilder <MSAst.Expression>(_items.Length + 1);
for (int i = 0; i < _items.Length; i++)
{
// target = array_temp[i]
Expression target = _items[i];
if (target == null)
{
continue;
}
// 6. array_temp[i]
MSAst.Expression element = Ast.ArrayAccess(
array_temp, // array expression
AstUtils.Constant(i) // index
);
// 7. target = array_temp[i], and add the transformed assignment into the list of sets
MSAst.Expression set = target.TransformSet(
emitIndividualSets ? // span
target.Span :
SourceSpan.None,
element,
PythonOperationKind.None
);
sets.Add(set);
}
// 9. add the sets as their own block so they can be marked as a single span, if necessary.
sets.Add(AstUtils.Empty());
MSAst.Expression itemSet = GlobalParent.AddDebugInfo(Ast.Block(sets.ToReadOnlyCollection()), leftSpan);
// 10. Return the suite statement (block)
return(GlobalParent.AddDebugInfo(Ast.Block(new[] { array_temp, right_temp }, assignStmt1, assignStmt2, itemSet, AstUtils.Empty()), totalSpan));
}
public override MSAst.Expression Reduce()
{
return(_left.TransformSet(Span, _right, PythonOperatorToAction(_op)));
}
