Method call translation performance improvement

Author: SteveWilkes

ReadableExpressions/Extensions/ReflectionExtensions.cs

@@ -1,10 +1,12 @@
 namespace AgileObjects.ReadableExpressions.Extensions
 {
+    using System.Diagnostics;
     using System.Reflection;
     using System.Runtime.CompilerServices;
 
     internal static class ReflectionExtensions
     {
+        [DebuggerStepThrough]
         public static bool IsExtensionMethod(this MethodInfo method)
         {
             return method.IsStatic && method.IsDefined(typeof(ExtensionAttribute), false);

ReadableExpressions/Translators/BclMethodInfoWrapper.cs

@@ -2,16 +2,17 @@ namespace AgileObjects.ReadableExpressions.Translators
 {
     using System;
     using System.Collections.Generic;
-    using System.Linq;
+    using System.Diagnostics;
     using System.Reflection;
     using Extensions;
 
     internal class BclMethodInfoWrapper : IMethodInfo
     {
         private readonly MethodInfo _method;
-        private IEnumerable<Type> _genericArguments;
+        private Type[] _genericArguments;
 
-        public BclMethodInfoWrapper(MethodInfo method, IEnumerable<Type> genericArguments = null)
+        [DebuggerStepThrough]
+        public BclMethodInfoWrapper(MethodInfo method, Type[] genericArguments = null)
         {
             _method = method;
             _genericArguments = genericArguments;
@@ -26,16 +27,19 @@ public BclMethodInfoWrapper(MethodInfo method, IEnumerable<Type> genericArgument
 
         public MethodInfo GetGenericMethodDefinition() => _method.GetGenericMethodDefinition();
 
-        public IEnumerable<Type> GetGenericArguments() =>
+        public IEnumerable<Type> GetGenericArguments() => GetGenericArgumentsArray();
+
+        private Type[] GetGenericArgumentsArray() =>
             (_genericArguments ?? (_genericArguments = _method.GetGenericArguments()));
 
         public IEnumerable<ParameterInfo> GetParameters() => _method.GetParameters();
 
         public Type GetGenericArgumentFor(Type parameterType)
         {
-            var parameterIndex = Array.IndexOf(_method.GetGenericArguments(), parameterType, 0);
+            var genericArguments = GetGenericArgumentsArray();
+            var parameterIndex = Array.IndexOf(genericArguments, parameterType, 0);
 
-            return _genericArguments.ElementAt(parameterIndex);
+            return genericArguments[parameterIndex];
         }
     }
 }

ReadableExpressions/Translators/DynamicExpressionTranslator.cs

@@ -40,13 +40,11 @@ public override string Translate(Expression expression, TranslationContext conte
             // way to go.
             foreach (var translator in _translators)
             {
-                string translated;
-
                 if (translator.TryTranslate(
                     operationDescription,
                     dynamicExpression,
                     context,
-                    out translated))
+                    out var translated))
                 {
                     return translated;
                 }
@@ -201,7 +199,7 @@ private static IMethodInfo GetMethodInfo(
                     GetGenericArgumentsOrNull(method, methodArguments, methodReturnType));
             }
 
-            private static IEnumerable<Type> GetGenericArgumentsOrNull(
+            private static Type[] GetGenericArgumentsOrNull(
                 MethodInfo method,
                 Expression[] methodArguments,
                 Type methodReturnType)

ReadableExpressions/Translators/Formatting/FormattableExpressionBase.cs

@@ -4,6 +4,8 @@ namespace AgileObjects.ReadableExpressions.Translators.Formatting
 
     internal abstract class FormattableExpressionBase
     {
+        private const int MaxLineLength = 100;
+
         public static implicit operator string(FormattableExpressionBase expression)
         {
             return expression.ToString();
@@ -24,7 +26,7 @@ protected string GetFormattedTranslation()
 
         protected virtual bool SplitToMultipleLines(string translation)
         {
-            return (translation.Length > 100) || translation.IsMultiLine();
+            return (translation.Length > MaxLineLength) || translation.IsMultiLine();
         }
 
         public override string ToString()

ReadableExpressions/Translators/MethodCallExpressionTranslator.cs

@@ -33,8 +33,7 @@ public override string Translate(Expression expression, TranslationContext conte
             }
 
             var methodCall = (MethodCallExpression)expression;
-            IEnumerable<Expression> methodArguments;
-            var methodCallSubject = GetMethodCallSubject(methodCall, context, out methodArguments);
+            var methodCallSubject = GetMethodCallSubject(methodCall, context, out var methodArguments);
 
             return GetMethodCall(
                 methodCallSubject,
@@ -46,9 +45,8 @@ public override string Translate(Expression expression, TranslationContext conte
 
         public static string GetMethodCallSubject(MethodCallExpression methodCall, TranslationContext context)
         {
-            IEnumerable<Expression> arguments;
-
-            return GetMethodCallSubject(methodCall, context, out arguments);
+            // ReSharper disable once UnusedVariable
+            return GetMethodCallSubject(methodCall, context, out var arguments);
         }
 
         private static string GetMethodCallSubject(
@@ -153,12 +151,7 @@ private static string GetGenericArgumentsIfNecessary(IMethodInfo method, Transla
                 .Where(name => name != null)
                 .ToArray();
 
-            if (!argumentNames.Any())
-            {
-                return null;
-            }
-
-            return $"<{string.Join(", ", argumentNames)}>";
+            return argumentNames.Any() ? $"<{string.Join(", ", argumentNames)}>" : null;
         }
 
         private static void RemoveSuppliedGenericTypeParameters(