internal static Expression MakeTest(CSharpPattern pattern, Expression @object, ExpressionType op, ConstantExpression value)
{
if (pattern.InputType == pattern.NarrowedType)
{
var obj = @object;
if (obj.Type != pattern.InputType)
{
obj = Expression.Convert(obj, pattern.InputType);
}
return
(Expression.MakeBinary(
op,
obj,
value
));
}
else
{
return(PatternHelpers.Reduce(@object, obj =>
{
return
Expression.AndAlso(
Expression.TypeIs(obj, pattern.NarrowedType),
Expression.MakeBinary(
op,
Expression.Convert(obj, pattern.NarrowedType),
value
)
);
}));
}
}
internal override Expression Reduce(Expression @object)
{
Expression createTest(Expression obj)
{
if (Variable != null)
{
var test = Expression.Parameter(typeof(bool), "__test");
return
(Expression.Block(
new[] { test },
Expression.Assign(test, Expression.TypeIs(obj, Type)),
Expression.IfThen(
test,
Expression.Assign(Variable, Expression.Convert(obj, Type))
),
test
));
}
else
{
return(Expression.TypeIs(obj, Type));
}
}
return(PatternHelpers.Reduce(@object, createTest));
}
/// <summary>
/// Reduces the pattern by applying it the specified object.
/// </summary>
/// <param name="object">The object to match the pattern against.</param>
/// <returns>The expression representing the pattern applied to the specified object.</returns>
internal override Expression Reduce(Expression @object)
{
Expression createTest(Expression obj)
{
return(Expression.MakeBinary(PatternType == CSharpPatternType.And ? ExpressionType.AndAlso : ExpressionType.OrElse, Left.Reduce(obj), Right.Reduce(obj)));
}
return(PatternHelpers.Reduce(@object, createTest));
}
internal Expression Reduce(Expression @object, List <ParameterExpression> vars, List <Expression> stmts, LabelTarget exit)
{
// NB: LengthOrCount is only used to refine the range of Int32 to >= 0. We don't yet use it for reduction.
Expression createTest(Expression obj)
{
return(Pattern.Reduce(Member.Reduce(obj, vars, stmts, exit)));
}
return(PatternHelpers.Reduce(@object, createTest, vars, stmts));
}
/// <summary>
/// Reduces the pattern by applying it the specified object.
/// </summary>
/// <param name="object">The object to match the pattern against.</param>
/// <returns>The expression representing the pattern applied to the specified object.</returns>
internal override Expression Reduce(Expression @object)
{
if (!AreReferenceAssignable(InputType, @object.Type))
{
throw LinqError.ExpressionTypeDoesNotMatchAssignment(@object.Type, InputType);
}
// NB: RecursiveCSharpPattern has a peephole optimization for the pattern below.
// NB: Ensure any side-effects in evaluating @object are retained.
return(PatternHelpers.Reduce(@object, _ => ConstantTrue));
}
/// <summary>
/// Reduces the pattern by applying it the specified object.
/// </summary>
/// <param name="object">The object to match the pattern against.</param>
/// <returns>The expression representing the pattern applied to the specified object.</returns>
internal override Expression Reduce(Expression @object)
{
// NB: RecursiveCSharpPattern has a peephole optimization for the pattern below.
if (Variable != null)
{
return
(Expression.Block(
Expression.Assign(Variable, @object),
ConstantTrue
));
}
else
{
// NB: Ensure any side-effects in evaluating @object are retained.
return(PatternHelpers.Reduce(@object, _ => ConstantTrue));
}
}
/// <summary>
/// Reduces the slice pattern by applying it the specified range in the specified object.
/// </summary>
/// <param name="object">The object to match the pattern against.</param>
/// <param name="length">The (optional) precomputed length of the object.</param>
/// <param name="range">The range to extract from the object.</param>
/// <returns>The expression representing the pattern applied to the specified object and range.</returns>
internal Expression Reduce(Expression @object, Expression length, Range range)
{
Expression GetSlice(Expression obj)
{
var rangeExpr = Expression.Constant(range);
if (IndexerAccess.Body is ArrayAccessCSharpExpression a &&
a.Array == IndexerAccess.Parameters[0] &&
a.Indexes.Count == 1 &&
a.Indexes[0] == IndexerAccess.Parameters[1])
{
var arrayAccess = a.Update(obj, new[] { rangeExpr });
return(arrayAccess.Reduce(length));
}
if (IndexerAccess.Body is IndexerAccessCSharpExpression i &&
i.Object == IndexerAccess.Parameters[0] &&
i.Argument == IndexerAccess.Parameters[1])
{
var indexerAccess = i.Update(obj, rangeExpr);
return(indexerAccess.Reduce(length));
}
return(Expression.Invoke(IndexerAccess, obj, rangeExpr));
}
return(PatternHelpers.Reduce(@object, obj =>
{
if (IndexerAccess != null && Pattern != null && Pattern.PatternType != CSharpPatternType.Discard)
{
var slice = GetSlice(obj);
return Pattern.Reduce(slice);
}
return ConstantTrue;
}));
}
internal override Expression Reduce(Expression @object)
{
Expression createTest(Expression obj)
{
var exit = Expression.Label(typeof(bool), "__return");
var stmts = new List <Expression>();
AddFailIfNot(Expression.TypeIs(obj, typeof(ITuple)), exit, stmts);
var temp = Expression.Parameter(typeof(ITuple), "__objT");
stmts.Add(Expression.Assign(temp, Expression.Convert(obj, typeof(ITuple))));
obj = temp;
var deconstructionCount = Deconstruction.Count;
AddFailIfNot(Expression.Equal(Expression.Call(obj, GetLengthMethod), CreateConstantInt32(deconstructionCount)), exit, stmts);
for (var i = 0; i < deconstructionCount; i++)
{
var deconstruction = Deconstruction[i];
var item = Expression.Call(obj, GetItemMethod, CreateConstantInt32(i));
var test = deconstruction.Pattern.Reduce(item);
AddFailIfNot(test, exit, stmts);
}
stmts.Add(Expression.Label(exit, ConstantTrue));
return(Expression.Block(new[] { temp }, stmts));
}
return(PatternHelpers.Reduce(@object, createTest));
}
/// <summary>
/// Reduces the pattern by applying it the specified object.
/// </summary>
/// <param name="object">The object to match the pattern against.</param>
/// <returns>The expression representing the pattern applied to the specified object.</returns>
internal override Expression Reduce(Expression @object)
{
return(PatternHelpers.Reduce(@object, obj => Expression.Not(Negated.Reduce(obj))));
}
/// <summary>
/// Reduces the pattern by applying it the specified object.
/// </summary>
/// <param name="object">The object to match the pattern against.</param>
/// <returns>The expression representing the pattern applied to the specified object.</returns>
internal override Expression Reduce(Expression @object)
{
Expression GetLength(Expression obj)
{
if (LengthAccess.Body is MemberExpression m &&
m.Expression == LengthAccess.Parameters[0])
{
return(m.Update(obj));
}
return(Expression.Invoke(LengthAccess, obj));
}
Expression GetElement(Expression obj, Expression length, Index index)
{
var indexExpr = Expression.Constant(index);
if (IndexerAccess.Body is ArrayAccessCSharpExpression a &&
a.Array == IndexerAccess.Parameters[0] &&
a.Indexes.Count == 1 &&
a.Indexes[0] == IndexerAccess.Parameters[1])
{
var arrayAccess = a.Update(obj, new[] { indexExpr });
return(arrayAccess.Reduce(length));
}
if (IndexerAccess.Body is IndexerAccessCSharpExpression i &&
i.Object == IndexerAccess.Parameters[0] &&
i.Argument == IndexerAccess.Parameters[1])
{
var indexerAccess = i.Update(obj, indexExpr);
return(indexerAccess.Reduce(length));
}
return(Expression.Invoke(IndexerAccess, obj, indexExpr));
}
bool HasSlice()
{
foreach (var p in Patterns)
{
if (p.PatternType == CSharpPatternType.Slice)
{
return(true);
}
}
return(false);
}
return(PatternHelpers.Reduce(@object, obj =>
{
var exit = Expression.Label(typeof(bool), "__return");
var vars = new List <ParameterExpression>();
var stmts = new List <Expression>();
obj = AddNullCheck(obj, typeCheck: null, exit, vars, stmts);
var n = Patterns.Count;
var length = GetLength(obj);
var hasSlice = HasSlice();
if (hasSlice)
{
var lengthTemp = Expression.Parameter(length.Type, "__len");
vars.Add(lengthTemp);
stmts.Add(Expression.Assign(lengthTemp, length));
length = new ReadOnlyTemporaryVariableExpression(lengthTemp);
}
var negatedLengthCheck = hasSlice
? Expression.LessThan(length, CreateConstantInt32(n - 1))
: Expression.NotEqual(length, CreateConstantInt32(n));
AddFailIf(negatedLengthCheck, exit, stmts);
var hasSeenSlice = false;
for (int i = 0; i < n; i++)
{
var p = Patterns[i];
if (p is SliceCSharpPattern slice)
{
hasSeenSlice = true;
var rangeStart = new Index(i);
var rangeEnd = new Index(n - i - 1, fromEnd: true);
var range = new Range(rangeStart, rangeEnd);
var sliceCheck = slice.Reduce(obj, length, range);
AddFailIfNot(sliceCheck, exit, stmts);
}
else if (p.PatternType != CSharpPatternType.Discard)
{
var index = hasSeenSlice
? new Index(n - i, fromEnd: true)
: new Index(i);
var element = GetElement(obj, length, index);
var elementCheck = p.Reduce(element);
AddFailIfNot(elementCheck, exit, stmts);
}
}
if (Variable != null)
{
stmts.Add(Expression.Assign(Variable, obj));
}
stmts.Add(Expression.Label(exit, ConstantTrue));
return Expression.Block(vars, stmts);
}));
}
internal override Expression Reduce(Expression @object)
{
Expression createTest(Expression obj)
{
var exit = Expression.Label(typeof(bool), "__return");
var vars = new List <ParameterExpression>();
var stmts = new List <Expression>();
obj = AddNullCheck(obj, Type, exit, vars, stmts);
if (Deconstruction.Count > 0)
{
if (DeconstructMethod != null)
{
var isExtensionMethod = DeconstructMethod.IsStatic;
var parameters = DeconstructMethod.GetParametersCached();
var parameterCount = parameters.Length;
if (isExtensionMethod)
{
parameterCount--;
}
var parameterToVariable = new Dictionary <ParameterInfo, ParameterExpression>(parameterCount);
var parameterIndexToVariable = new ParameterExpression[parameterCount];
var deconstructArgs = new Expression[parameterCount];
for (var i = 0; i < parameterCount; i++)
{
var parameter = parameters[isExtensionMethod ? i + 1 : i];
Debug.Assert(parameter.IsOut && parameter.IsByRefParameter());
var type = parameter.ParameterType.GetElementType();
var temp = Expression.Parameter(type, "__obj_d" + i);
vars.Add(temp);
parameterToVariable.Add(parameter, temp);
parameterIndexToVariable[i] = temp;
deconstructArgs[i] = temp;
}
var deconstruct = isExtensionMethod
? Expression.Call(DeconstructMethod, deconstructArgs.AddFirst(obj))
: Expression.Call(obj, DeconstructMethod, deconstructArgs);
stmts.Add(deconstruct);
var deconstructionCount = Deconstruction.Count;
for (var i = 0; i < deconstructionCount; i++)
{
var deconstruction = Deconstruction[i];
var var = deconstruction.Parameter != null ? parameterToVariable[deconstruction.Parameter] : parameterIndexToVariable[i];
var test = deconstruction.Pattern.Reduce(var);
AddFailIfNot(test, exit, stmts);
}
}
else
{
var deconstructionCount = Deconstruction.Count;
for (var i = 0; i < deconstructionCount; i++)
{
var deconstruction = Deconstruction[i];
var index = deconstruction.Field?.Index ?? i;
var item = GetTupleItemAccess(obj, index);
var test = deconstruction.Pattern.Reduce(item);
AddFailIfNot(test, exit, stmts);
}
}
}
if (Properties.Count > 0)
{
foreach (var prop in Properties)
{
var test = prop.Reduce(obj, vars, stmts, exit);
AddFailIfNot(test, exit, stmts);
}
}
if (Variable != null)
{
stmts.Add(Expression.Assign(Variable, obj));
}
stmts.Add(Expression.Label(exit, ConstantTrue));
return(Expression.Block(vars, stmts));
}
return(PatternHelpers.Reduce(@object, createTest));
}