| public static PostDecrementAssign ( Expression expression ) : UnaryExpression | ||
| expression | Expression | An |
| return | UnaryExpression | |
// Pseudocode:
//string input =>
//{
// R result = 0;
// for (int i = input.Length - 1; i >= 0; i--)
// {
// result <<= 6;
// var m = _invMap[input[i]];
// if (m == 0xff)
// return default(ConversionResult<R>);
// result += m;
// }
// return new ConversionResult<R>(result);
//}
private LambdaExpression fromLambda(Type to)
{
var stringthis = typeof(string).GetTypeInfo().DeclaredProperties.First(p => p.GetIndexParameters().Length == 1 && p.GetIndexParameters()[0].ParameterType == typeof(int));
var input = Ex.Parameter(typeof(string), "input");
var result = Ex.Parameter(to, "result");
var i = Ex.Parameter(typeof(int), "i");
var m = Ex.Parameter(typeof(byte), "m");
var loopstart = Ex.Label("loopstart");
var end = Ex.Label(typeof(ConversionResult <>).MakeGenericType(to), "end");
var loop = Ex.Block(
Ex.Label(loopstart),
Ex.IfThen(Ex.MakeBinary(ExpressionType.LessThan, i, Ex.Constant(0)),
Ex.Goto(end, Result(to, result))),
Ex.LeftShiftAssign(result, Ex.Constant(6)),
Ex.Assign(m, Ex.ArrayIndex(Ex.Constant(_invMap), Ex.Convert(Ex.MakeIndex(input, stringthis, new[] { i }), typeof(int)))),
Ex.IfThen(Ex.MakeBinary(ExpressionType.Equal, m, Ex.Constant((byte)0xff)),
Ex.Goto(end, NoResult(to))),
Ex.AddAssign(result, Ex.Convert(m, result.Type)),
Ex.PostDecrementAssign(i),
Ex.Goto(loopstart));
var block = Ex.Block(new[] { result, i, m },
Ex.Assign(result, Ex.Convert(Ex.Constant(0), to)),
Ex.Assign(i, Ex.MakeBinary(ExpressionType.Subtract, Ex.Property(input, nameof(string.Length)), Ex.Constant(1))),
loop,
Ex.Label(end, NoResult(to)));
return(Ex.Lambda(block, input));
}
public void Factorial()
{
var value = LinqExpression.Parameter(typeof(int), "value");
var result = LinqExpression.Parameter(typeof(int), "result");
var label = LinqExpression.Label(typeof(int), "label");
var one = LinqExpression.Constant(1);
var expression = LinqExpression.Block(
new[] { result },
LinqExpression.Assign(
result,
one),
LinqExpression.Loop(
LinqExpression.Condition(
LinqExpression.GreaterThan(
value,
one),
LinqExpression.MultiplyAssign(
result,
LinqExpression.PostDecrementAssign(
value)),
LinqExpression.Break(
label,
result),
typeof(void)),
label));
ShouldRoundrip(expression);
}
private UnaryExpression UnaryExpression(
ExpressionType nodeType, System.Type type, JObject obj)
{
var operand = this.Prop(obj, "operand", this.Expression);
var method = this.Prop(obj, "method", this.Method);
switch (nodeType)
{
case ExpressionType.ArrayLength: return(Expr.ArrayLength(operand));
case ExpressionType.Convert: return(Expr.Convert(operand, type, method));
case ExpressionType.ConvertChecked: return(Expr.ConvertChecked(operand, type, method));
case ExpressionType.Decrement: return(Expr.Decrement(operand, method));
case ExpressionType.Increment: return(Expr.Increment(operand, method));
case ExpressionType.IsFalse: return(Expr.IsFalse(operand, method));
case ExpressionType.IsTrue: return(Expr.IsTrue(operand, method));
case ExpressionType.Negate: return(Expr.Negate(operand, method));
case ExpressionType.NegateChecked: return(Expr.NegateChecked(operand, method));
case ExpressionType.Not: return(Expr.Not(operand, method));
case ExpressionType.OnesComplement: return(Expr.OnesComplement(operand, method));
case ExpressionType.PostDecrementAssign: return(Expr.PostDecrementAssign(operand, method));
case ExpressionType.PostIncrementAssign: return(Expr.PostIncrementAssign(operand, method));
case ExpressionType.PreDecrementAssign: return(Expr.PreDecrementAssign(operand, method));
case ExpressionType.PreIncrementAssign: return(Expr.PreIncrementAssign(operand, method));
case ExpressionType.Quote: return(Expr.Quote(operand));
case ExpressionType.Throw: return(Expr.Throw(operand, type));
case ExpressionType.TypeAs: return(Expr.TypeAs(operand, type));
case ExpressionType.UnaryPlus: return(Expr.UnaryPlus(operand, method));
case ExpressionType.Unbox: return(Expr.Unbox(operand, type));
default: throw new NotSupportedException();
}
}
public void Factorial()
{
var value = LinqExpression.Parameter(typeof(int));
var result = LinqExpression.Parameter(typeof(int));
var label = LinqExpression.Label(typeof(int));
var expected = LinqExpression.Block(
new[] { result },
LinqExpression.Assign(
result,
LinqExpression.Constant(1)),
LinqExpression.Loop(
LinqExpression.Condition(
LinqExpression.GreaterThan(
value,
LinqExpression.Constant(1)),
LinqExpression.MultiplyAssign(
result,
LinqExpression.PostDecrementAssign(
value)),
LinqExpression.Break(
label,
result),
typeof(void)),
label));
using var g = new GraphEngine.Graph();
g.LoadFromString(@"
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix : <http://example.com/> .
@prefix xt: <http://example.com/ExpressionTypes/> .
_:constantValue
:parameterType [
:typeName ""System.Int32"" ;
] ;
.
_:result
:parameterType [
:typeName ""System.Int32"" ;
] ;
.
_:label
:targetType [
:typeName ""System.Int32"" ;
] ;
.
_:one
:constantValue ""1""^^xsd:int ;
.
:s
:blockVariables (
_:result
) ;
:blockExpressions (
[
:binaryExpressionType xt:Assign ;
:binaryLeft _:result ;
:binaryRight _:one ;
]
[
:loopBody [
:conditionTest [
:binaryExpressionType xt:GreaterThan ;
:binaryLeft _:constantValue ;
:binaryRight _:one ;
] ;
:conditionIfTrue [
:binaryExpressionType xt:MultiplyAssign ;
:binaryLeft _:result ;
:binaryRight [
:unaryExpressionType xt:PostDecrementAssign ;
:unaryOperand _:constantValue ;
] ;
] ;
:conditionIfFalse [
a :Break ;
:gotoTarget _:label ;
:gotoValue _:result ;
] ;
:conditionType [
:typeName ""System.Void"" ;
] ;
] ;
:loopBreak _:label ;
]
) ;
.
");
var s = g.GetUriNode(":s");
var actual = Expression.Parse(s).LinqExpression;
Console.WriteLine(actual.GetDebugView());
actual.Should().Be(expected);
}
