mirror of https://github.com/sean-m/McRule.git
56 lines
2.2 KiB
C#
56 lines
2.2 KiB
C#
using System.Linq.Expressions;
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namespace McRule;
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// Taken from LinqKit, Joseph Albahari. Man is a legend.
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// LINQKit Copyright (c) 2007-2009 Joseph Albahari, Tomas Petricek
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//
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// The Expression Visitor class is based on a Microsoft sample.
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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public static class PredicateBuilder
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{
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public static Expression<Func<T, bool>> True<T>()
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{
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return f => true;
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}
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public static Expression<Func<T, bool>> False<T>()
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{
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return f => false;
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}
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public static Expression<Func<T, bool>> Or<T>(this Expression<Func<T, bool>> expr1,
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Expression<Func<T, bool>> expr2)
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{
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var invokedExpr = Expression.Invoke(expr2, expr1.Parameters.Cast<Expression>());
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return Expression.Lambda<Func<T, bool>>
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(Expression.OrElse(expr1.Body, invokedExpr), expr1.Parameters);
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}
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public static Expression<Func<T, bool>> And<T>(this Expression<Func<T, bool>> expr1,
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Expression<Func<T, bool>> expr2)
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{
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var invokedExpr = Expression.Invoke(expr2, expr1.Parameters.Cast<Expression>());
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return Expression.Lambda<Func<T, bool>>
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(Expression.AndAlso(expr1.Body, invokedExpr), expr1.Parameters);
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}
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}
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