Expose UnaryExpressionHelpers and BinaryExpressionHelpers

src/UiPath.Workflow.Runtime/Expressions/AddAssign.cs

@@ -0,0 +1,98 @@
+// This file is part of Core WF which is licensed under the MIT license.
+// See LICENSE file in the project root for full license information.
+
+using System.Activities.Validation;
+using System.ComponentModel;
+using System.Linq.Expressions;
+using System.Numerics;
+
+namespace System.Activities.Expressions
+{
+    /// <summary>
+    /// A code activity which incrementally assigns a numeral.
+    /// </summary>
+    /// <example>
+    /// int myNum = 5;
+    /// myNum += 5; // 10.
+    /// </example>
+    /// <typeparam name="TLeft">The operand to modify.</typeparam>
+    /// <typeparam name="TRight">The operand with which to modify <typeparamref name="TLeft"/>.</typeparam>
+    /// <typeparam name="TResult">The resulting type of hte operation.</typeparam>
+    public sealed class AddAssign<TLeft, TRight, TResult> : CodeActivity<TResult>
+#if NET7_0_OR_GREATER
+        where TLeft : INumber<TLeft>
+        where TRight : INumber<TRight>
+        where TResult : INumber<TResult>
+#endif
+    {
+        private static Func<TLeft, TRight, TResult>? checkedOperationFunction = null;
+        private static Func<TLeft, TRight, TResult>? uncheckedOperationFunction = null;
+
+        /// <summary>
+        /// Gets or sets the left operand which will be modified by this operation.
+        /// </summary>
+        [RequiredArgument]
+        public InArgument<TLeft> Left { get; set; } = new();
+
+        /// <summary>
+        /// Gets or sets the right operand which will be the modifier for this operation.
+        /// </summary>
+        [RequiredArgument]
+        public InArgument<TRight> Right { get; set; } = new();
+
+        /// <summary>
+        /// Gets or sets a value indicating whether this operation will happen in a checked or unchecked context.
+        /// </summary>
+        [DefaultValue(true)]
+        public bool IsChecked { get; set; } = true;
+
+        /// <inheritdoc/>
+        protected override void CacheMetadata(CodeActivityMetadata metadata)
+        {
+            BinaryExpressionHelper.OnGetArguments(metadata, Left, Right);
+
+            if (IsChecked)
+            {
+                EnsureOperationFunction(metadata, ref checkedOperationFunction, ExpressionType.AddAssignChecked);
+            }
+            else
+            {
+                EnsureOperationFunction(metadata, ref uncheckedOperationFunction, ExpressionType.AddAssign);
+            }
+        }
+
+        private static void EnsureOperationFunction
+        (
+            CodeActivityMetadata metadata,
+            ref Func<TLeft, TRight, TResult>? operationFunction,
+            ExpressionType operatorType
+        )
+        {
+            if (operationFunction == null)
+            {
+                if (!BinaryExpressionHelper.TryGenerateLinqDelegate(
+                    operatorType,
+                    out operationFunction,
+                    out ValidationError? validationError))
+                {
+                    metadata.AddValidationError(validationError);
+                }
+            }
+        }
+
+        /// <inheritdoc/>
+        protected override TResult Execute(CodeActivityContext context)
+        {
+            TLeft leftValue = Left.Get(context);
+            TRight rightValue = Right.Get(context);
+
+            // If user changed checked flag between open and execution, an NRE may be thrown.
+            // This is by design.
+            // Nullability check silenced because the corresponding value is guaranteed to be
+            // non-null
+            return IsChecked
+                ? checkedOperationFunction!(leftValue, rightValue)
+                : uncheckedOperationFunction!(leftValue, rightValue);
+        }
+    }
+}

src/UiPath.Workflow.Runtime/Expressions/BinaryExpressionHelper.cs

@@ -8,8 +8,19 @@
 
 namespace System.Activities.Expressions;
 
-internal static class BinaryExpressionHelper
+/// <summary>
+/// Helpers for binary expressions.
+/// </summary>
+public static class BinaryExpressionHelper
 {
+    /// <summary>
+    /// Binds metadata when getting arguments.
+    /// </summary>
+    /// <typeparam name="TLeft">The type of the left argument.</typeparam>
+    /// <typeparam name="TRight">The type of the right argument.</typeparam>
+    /// <param name="metadata">The metadata.</param>
+    /// <param name="left">The left argument.</param>
+    /// <param name="right">The right argument.</param>
     public static void OnGetArguments<TLeft, TRight>(CodeActivityMetadata metadata, InArgument<TLeft> left, InArgument<TRight> right)
     {
         RuntimeArgument rightArgument = new("Right", typeof(TRight), ArgumentDirection.In, true);
@@ -26,6 +37,16 @@ public static void OnGetArguments<TLeft, TRight>(CodeActivityMetadata metadata,
             });
     }
 
+    /// <summary>
+    /// Generates a <see cref="System.Linq"/> delegate.
+    /// </summary>
+    /// <typeparam name="TLeft">The type of the left argument.</typeparam>
+    /// <typeparam name="TRight">The type of the right argument.</typeparam>
+    /// <typeparam name="TResult">The return type of the operation.</typeparam>
+    /// <param name="operatorType">The type of expression.</param>
+    /// <param name="function">The resulting <see cref="Func{T1, T2, TResult}"/>.</param>
+    /// <param name="validationError">If the operation failed, the error.</param>
+    /// <returns><see langword="true"/> if the operation was successful; otherwise, <see langword="false"/>.</returns>
     public static bool TryGenerateLinqDelegate<TLeft, TRight, TResult>(ExpressionType operatorType, out Func<TLeft, TRight, TResult> function, out ValidationError validationError)
     {
         function = null;

src/UiPath.Workflow.Runtime/Expressions/Decrement.cs

@@ -0,0 +1,57 @@
+// This file is part of Core WF which is licensed under the MIT license.
+// See LICENSE file in the project root for full license information.
+
+using System.Activities.Validation;
+using System.Linq.Expressions;
+using System.Numerics;
+
+namespace System.Activities.Expressions
+{
+    /// <summary>
+    /// A code activity which decrements a numeral.
+    /// </summary>
+    /// <typeparam name="TNumeral">A numeric value, such as <see langword="int" /> or <see langword="long" />.</typeparam>
+    public sealed class Decrement<TNumeral> : CodeActivity<TNumeral>
+#if NET7_0_OR_GREATER
+        where TNumeral : IIncrementOperators<TNumeral>
+#endif
+    {
+        private static Func<TNumeral, TNumeral>? operationFunction = null!;
+
+        /// <summary>
+        /// Gets or sets the numeral value that will be incremented.
+        /// </summary>
+        [RequiredArgument]
+        public InOutArgument<TNumeral> Numeral { get; set; } = new();
+
+        /// <inheritdoc/>
+        protected override void CacheMetadata(CodeActivityMetadata metadata)
+        {
+            UnaryExpressionHelper.OnGetArguments(metadata, Numeral);
+            EnsureOperationFunction(metadata, ref operationFunction!, ExpressionType.Decrement);
+        }
+
+        private static void EnsureOperationFunction
+        (
+            CodeActivityMetadata metadata,
+            ref Func<TNumeral, TNumeral> operationFunction,
+            ExpressionType operatorType
+        )
+        {
+            if (operationFunction is null)
+            {
+                if (!UnaryExpressionHelper.TryGenerateLinqDelegate(operatorType, out operationFunction!, out ValidationError? validationError))
+                {
+                    metadata.AddValidationError(validationError);
+                }
+            }
+        }
+
+        /// <inheritdoc/>
+        protected override TNumeral Execute(CodeActivityContext context)
+        {
+            TNumeral value = Numeral.Get(context);
+            return operationFunction!.Invoke(value);
+        }
+    }
+}

src/UiPath.Workflow.Runtime/Expressions/Increment.cs

@@ -0,0 +1,57 @@
+// This file is part of Core WF which is licensed under the MIT license.
+// See LICENSE file in the project root for full license information.
+
+using System.Activities.Validation;
+using System.Linq.Expressions;
+using System.Numerics;
+
+namespace System.Activities.Expressions
+{
+    /// <summary>
+    /// A code activity which increments a numeral.
+    /// </summary>
+    /// <typeparam name="TNumeral">A numeric value, such as <see langword="int" /> or <see langword="long" />.</typeparam>
+    public sealed class Increment<TNumeral> : CodeActivity<TNumeral>
+#if NET7_0_OR_GREATER
+        where TNumeral : IIncrementOperators<TNumeral>
+#endif
+    {
+        private static Func<TNumeral, TNumeral>? operationFunction = null!;
+
+        /// <summary>
+        /// Gets or sets the numeral value that will be incremented.
+        /// </summary>
+        [RequiredArgument]
+        public InOutArgument<TNumeral> Numeral { get; set; } = new();
+
+        /// <inheritdoc/>
+        protected override void CacheMetadata(CodeActivityMetadata metadata)
+        {
+            UnaryExpressionHelper.OnGetArguments<TNumeral>(metadata, Numeral);
+            EnsureOperationFunction(metadata, ref operationFunction!, ExpressionType.Increment);
+        }
+
+        private static void EnsureOperationFunction
+        (
+            CodeActivityMetadata metadata,
+            ref Func<TNumeral, TNumeral> operationFunction,
+            ExpressionType operatorType
+        )
+        {
+            if (operationFunction is null)
+            {
+                if (!UnaryExpressionHelper.TryGenerateLinqDelegate(operatorType, out operationFunction!, out ValidationError? validationError))
+                {
+                    metadata.AddValidationError(validationError);
+                }
+            }
+        }
+
+        /// <inheritdoc/>
+        protected override TNumeral Execute(CodeActivityContext context)
+        {
+            TNumeral value = Numeral.Get(context);
+            return operationFunction!.Invoke(value);
+        }
+    }
+}

src/UiPath.Workflow.Runtime/Expressions/SubtractAssign.cs

@@ -0,0 +1,98 @@
+// This file is part of Core WF which is licensed under the MIT license.
+// See LICENSE file in the project root for full license information.
+
+using System.Activities.Validation;
+using System.ComponentModel;
+using System.Linq.Expressions;
+using System.Numerics;
+
+namespace System.Activities.Expressions
+{
+    /// <summary>
+    /// A code activity which deccrementally assigns a numeral.
+    /// </summary>
+    /// <example>
+    /// int myNum = 5;
+    /// myNum += 5; // 10.
+    /// </example>
+    /// <typeparam name="TLeft">The operand to modify.</typeparam>
+    /// <typeparam name="TRight">The operand with which to modify <typeparamref name="TLeft"/>.</typeparam>
+    /// <typeparam name="TResult">The resulting type of hte operation.</typeparam>
+    public sealed class SubtractAssign<TLeft, TRight, TResult> : CodeActivity<TResult>
+#if NET7_0_OR_GREATER
+        where TLeft : INumber<TLeft>
+        where TRight : INumber<TRight>
+        where TResult : INumber<TResult>
+#endif
+    {
+        private static Func<TLeft, TRight, TResult>? checkedOperationFunction = null;
+        private static Func<TLeft, TRight, TResult>? uncheckedOperationFunction = null;
+
+        /// <summary>
+        /// Gets or sets the left operand which will be modified by this operation.
+        /// </summary>
+        [RequiredArgument]
+        public InArgument<TLeft> Left { get; set; } = new();
+
+        /// <summary>
+        /// Gets or sets the right operand which will be the modifier for this operation.
+        /// </summary>
+        [RequiredArgument]
+        public InArgument<TRight> Right { get; set; } = new();
+
+        /// <summary>
+        /// Gets or sets a value indicating whether this operation will happen in a checked or unchecked context.
+        /// </summary>
+        [DefaultValue(true)]
+        public bool IsChecked { get; set; } = true;
+
+        /// <inheritdoc/>
+        protected override void CacheMetadata(CodeActivityMetadata metadata)
+        {
+            BinaryExpressionHelper.OnGetArguments(metadata, Left, Right);
+
+            if (IsChecked)
+            {
+                EnsureOperationFunction(metadata, ref checkedOperationFunction, ExpressionType.SubtractAssignChecked);
+            }
+            else
+            {
+                EnsureOperationFunction(metadata, ref uncheckedOperationFunction, ExpressionType.SubtractAssign);
+            }
+        }
+
+        private static void EnsureOperationFunction
+        (
+            CodeActivityMetadata metadata,
+            ref Func<TLeft, TRight, TResult>? operationFunction,
+            ExpressionType operatorType
+        )
+        {
+            if (operationFunction == null)
+            {
+                if (!BinaryExpressionHelper.TryGenerateLinqDelegate(
+                    operatorType,
+                    out operationFunction,
+                    out ValidationError? validationError))
+                {
+                    metadata.AddValidationError(validationError);
+                }
+            }
+        }
+
+        /// <inheritdoc/>
+        protected override TResult Execute(CodeActivityContext context)
+        {
+            TLeft leftValue = Left.Get(context);
+            TRight rightValue = Right.Get(context);
+
+            // If user changed checked flag between open and execution, an NRE may be thrown.
+            // This is by design.
+            // Nullability check silenced because the corresponding value is guaranteed to be
+            // non-null
+            return IsChecked
+                ? checkedOperationFunction!(leftValue, rightValue)
+                : uncheckedOperationFunction!(leftValue, rightValue);
+        }
+    }
+}