Update IMemory interface and tryEvaluate for expression (#3635)

* expand the interface expression evaluation to take an extra option

* expand IMemory to accept a boolean flag

* Update ExpressionEvaluator.cs

* adjust the order of parameter of EvalauteChildren

* fix boolean context in where

* fix doc

* fix customzied memory in LG

* fix customized funtion inside onConditions

* fix doc

* Swallow error in bool

* Fix DSM for the new interface

* Revert "Fix DSM for the new interface"

This reverts commit ae1aa0e.

* Switch to a specific null substitution delegate

* Fix Element

* fix the type issue

* revert LG memory change

* update OnCondition

* Remove delegate in favor of Func

* Add constructor and copy constructor

* Made comparision boolean context also with test cases

* remove unintended change in csproj

* revert changes in csproj

* go back using Comparison for bool()

* catch error in Where func

libraries/AdaptiveExpressions/Constant.cs

@@ -20,7 +20,7 @@ public class Constant : Expression
         /// </summary>
         /// <param name="value">Constant value.</param>
         public Constant(object value = null)
-            : base(new ExpressionEvaluator(ExpressionType.Constant, (expression, state) => ((expression as Constant).Value, null)))
+            : base(new ExpressionEvaluator(ExpressionType.Constant, (expression, state, _) => ((expression as Constant).Value, null)))
         {
             Value = value;
         }

libraries/AdaptiveExpressions/Expression.cs

@@ -177,7 +177,7 @@ public static Expression LambaExpression(EvaluateExpressionDelegate function)
         /// <param name="function">Lambda expression to evaluate.</param>
         /// <returns>New expression.</returns>
         public static Expression Lambda(Func<object, object> function)
-            => new Expression(new ExpressionEvaluator(ExpressionType.Lambda, (expression, state) =>
+            => new Expression(new ExpressionEvaluator(ExpressionType.Lambda, (expression, state, _) =>
             {
                 object value = null;
                 string error = null;
@@ -481,9 +481,10 @@ public void ValidateTree()
         /// Global state to evaluate accessor expressions against.  Can be <see cref="System.Collections.Generic.IDictionary{String, Object}"/>,
         /// <see cref="System.Collections.IDictionary"/> otherwise reflection is used to access property and then indexer.
         /// </param>
+        /// <param name="options">Options used in the evaluation. </param>
         /// <returns>Computed value and an error string.  If the string is non-null, then there was an evaluation error.</returns>
-        public (object value, string error) TryEvaluate(object state)
-            => this.TryEvaluate<object>(MemoryFactory.Create(state));
+        public (object value, string error) TryEvaluate(object state, Options options = null)
+            => this.TryEvaluate<object>(MemoryFactory.Create(state), options);
 
         /// <summary>
         /// Evaluate the expression.
@@ -492,9 +493,10 @@ public void ValidateTree()
         /// Global state to evaluate accessor expressions against.  Can be <see cref="System.Collections.Generic.IDictionary{String, Object}"/>,
         /// <see cref="System.Collections.IDictionary"/> otherwise reflection is used to access property and then indexer.
         /// </param>
+        /// <param name="options">Options used in the evaluation. </param>
         /// <returns>Computed value and an error string.  If the string is non-null, then there was an evaluation error.</returns>
-        public (object value, string error) TryEvaluate(IMemory state)
-            => this.TryEvaluate<object>(state);
+        public (object value, string error) TryEvaluate(IMemory state, Options options = null)
+            => this.TryEvaluate<object>(state, options);
 
         /// <summary>
         /// Evaluate the expression.
@@ -504,9 +506,10 @@ public void ValidateTree()
         /// Global state to evaluate accessor expressions against.  Can be <see cref="System.Collections.Generic.IDictionary{String, Object}"/>,
         /// <see cref="System.Collections.IDictionary"/> otherwise reflection is used to access property and then indexer.
         /// </param>
+        /// <param name="options">Options used in the evaluation. </param>
         /// <returns>Computed value and an error string.  If the string is non-null, then there was an evaluation error.</returns>
-        public (T value, string error) TryEvaluate<T>(object state)
-        => this.TryEvaluate<T>(MemoryFactory.Create(state));
+        public (T value, string error) TryEvaluate<T>(object state, Options options = null)
+        => this.TryEvaluate<T>(MemoryFactory.Create(state), options);
 
         /// <summary>
         /// Evaluate the expression.
@@ -516,10 +519,12 @@ public void ValidateTree()
         /// Global state to evaluate accessor expressions against.  Can be <see cref="System.Collections.Generic.IDictionary{String, Object}"/>,
         /// <see cref="System.Collections.IDictionary"/> otherwise reflection is used to access property and then indexer.
         /// </param>
+        /// <param name="options">Options used in the evaluation. </param>
         /// <returns>Computed value and an error string.  If the string is non-null, then there was an evaluation error.</returns>
-        public (T value, string error) TryEvaluate<T>(IMemory state)
+        public (T value, string error) TryEvaluate<T>(IMemory state, Options options = null)
         {
-            var (result, error) = Evaluator.TryEvaluate(this, state);
+            var opts = options ?? new Options();
+            var (result, error) = Evaluator.TryEvaluate(this, state, opts);
             if (error != null)
             {
                 return (default(T), error);

libraries/AdaptiveExpressions/ExpressionEvaluator.cs

@@ -22,8 +22,9 @@ namespace AdaptiveExpressions
     /// </remarks>
     /// <param name="expression">Expression to evaluate.</param>
     /// <param name="state">Global state information.</param>
+    /// <param name="options">Options for the evaluation.</param>
     /// <returns>Value and error string that is non-null if there is an error.</returns>
-    public delegate (object value, string error) EvaluateExpressionDelegate(Expression expression, IMemory state);
+    public delegate (object value, string error) EvaluateExpressionDelegate(Expression expression, IMemory state, Options options);
 
     /// <summary>
     /// Delegate to lookup function information from the type.
@@ -105,9 +106,10 @@ public ExpressionEvaluator Negation
         /// </summary>
         /// <param name="expression">Expression to evaluate.</param>
         /// <param name="state">Global state information.</param>
+        /// <param name="options">Options used in the evaluation. </param>
         /// <returns>Value and error string that is non-null if there is an error.</returns>
-        public (object value, string error) TryEvaluate(Expression expression, IMemory state)
-            => _evaluator(expression, state);
+        public (object value, string error) TryEvaluate(Expression expression, IMemory state, Options options)
+            => _evaluator(expression, state, options);
 
         /// <summary>
         /// Validate an expression.