Evaluate

In Archive Tags #imported #archived Published 4. 05. 2007 3 comments

Najbrž vsi poznate JS ukaz evaluate(eval), kjer mu podaš JS kodo v obliki stringa in on to izvede.

Obstaja kaj takega v c#?

Recimo v enem stringu imam nek ime: "MyClass.Test". Imam tudi tak objekt:
public static class MyClass
{
    public static Test { get { return "bla"; } }
}

Sedaj pa bi rad v eno spremenljivko dobil ta bla na podlagi stringa, ki predstavlja objekt:

public string Get(string _Eval)
{
    return Evaluate(_Eval);    //vrnil bi "bla"
}

Seveda mora stvar biti zelo hitra, drugače mi ne pomaga.
Obstaja kaj takega?

Avtor: fora, objavljeno na portalu SloDug.si (Arhiv)

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spirit1
spirit1 - petek, 04. maj 2007

o hudica.. se ti je pa dalo  Fora:mogoce bi ti DynamicMethod bil bolj v pomoc. glavno vprasanje je seveda, zakaj hoces to narediti? 

DejanStanic
DejanStanic - petek, 04. maj 2007

using System; System;using System.CodeDom.Compiler; System.CodeDom.Compiler;using System.Reflection; System.Reflection;using Microsoft.JScript; Microsoft.JScript;namespace Infoteh.Classes.Numerics{public static class Evaluator Infoteh.Classes.Numerics{public static class Evaluatorpublic static class Evaluator{static Evaluator(){CodeDomProvider cdp = new JScriptCodeProvider();CompilerParameters cp = new CompilerParameters();cp.GenerateInMemory = true;CompilerResults cr = cdp.CompileAssemblyFromSource(cp, source);Assembly assembly = cr.CompiledAssembly;type = assembly.GetType("Evaluator.Evaluator");evaluator = Activator.CreateInstance(type);}private static object evaluator = null;private static Type type = null;private static readonly string source = @"package Evaluator{class Evaluator{public function Eval(expr: String): String{return eval(expr);}}}";public static object AsObject(string expression){trystatic Evaluator(){CodeDomProvider cdp = new JScriptCodeProvider();CompilerParameters cp = new CompilerParameters();cp.GenerateInMemory = true;CompilerResults cr = cdp.CompileAssemblyFromSource(cp, source);Assembly assembly = cr.CompiledAssembly;type = assembly.GetType("Evaluator.Evaluator");evaluator = Activator.CreateInstance(type);}private static object evaluator = null;private static Type type = null;private static readonly string source = @"package Evaluator{class Evaluator{public function Eval(expr: String): String{return eval(expr);}}}";public static object AsObject(string expression){tryCodeDomProvider cdp = new JScriptCodeProvider();CompilerParameters cp = new CompilerParameters();cp.GenerateInMemory = true;CompilerResults cr = cdp.CompileAssemblyFromSource(cp, source);Assembly assembly = cr.CompiledAssembly;type = assembly.GetType("Evaluator.Evaluator");evaluator = Activator.CreateInstance(type);}private static object evaluator = null;private static Type type = null;private static readonly string source = @"package Evaluator{class Evaluator{public function Eval(expr: String): String{return eval(expr);}}}";public static object AsObject(string expression){tryCompilerParameters cp = new CompilerParameters();cp.GenerateInMemory = true;CompilerResults cr = cdp.CompileAssemblyFromSource(cp, source);Assembly assembly = cr.CompiledAssembly;type = assembly.GetType("Evaluator.Evaluator");evaluator = Activator.CreateInstance(type);}private static object evaluator = null;private static Type type = null;private static readonly string source = @"package Evaluator{class Evaluator{public function Eval(expr: String): String{return eval(expr);}}}";public static object AsObject(string expression){trytrue;CompilerResults cr = cdp.CompileAssemblyFromSource(cp, source);Assembly assembly = cr.CompiledAssembly;type = assembly.GetType("Evaluator.Evaluator");evaluator = Activator.CreateInstance(type);}private static object evaluator = null;private static Type type = null;private static readonly string source = @"package Evaluator{class Evaluator{public function Eval(expr: String): String{return eval(expr);}}}";public static object AsObject(string expression){tryCompilerResults cr = cdp.CompileAssemblyFromSource(cp, source);Assembly assembly = cr.CompiledAssembly;type = assembly.GetType("Evaluator.Evaluator");evaluator = Activator.CreateInstance(type);}private static object evaluator = null;private static Type type = null;private static readonly string source = @"package Evaluator{class Evaluator{public function Eval(expr: String): String{return eval(expr);}}}";public static object AsObject(string expression){tryAssembly assembly = cr.CompiledAssembly;type = assembly.GetType("Evaluator.Evaluator");evaluator = Activator.CreateInstance(type);}private static object evaluator = null;private static Type type = null;private static readonly string source = @"package Evaluator{class Evaluator{public function Eval(expr: String): String{return eval(expr);}}}";public static object AsObject(string expression){try"Evaluator.Evaluator");evaluator = Activator.CreateInstance(type);}private static object evaluator = null;private static Type type = null;private static readonly string source = @"package Evaluator{class Evaluator{public function Eval(expr: String): String{return eval(expr);}}}";public static object AsObject(string expression){tryActivator.CreateInstance(type);}private static object evaluator = null;private static Type type = null;private static readonly string source = @"package Evaluator{class Evaluator{public function Eval(expr: String): String{return eval(expr);}}}";public static object AsObject(string expression){tryprivate static object evaluator = null;private static Type type = null;private static readonly string source = @"package Evaluator{class Evaluator{public function Eval(expr: String): String{return eval(expr);}}}";public static object AsObject(string expression){tryprivate static Type type = null;private static readonly string source = @"package Evaluator{class Evaluator{public function Eval(expr: String): String{return eval(expr);}}}";public static object AsObject(string expression){tryprivate static readonly string source = @"package Evaluator{class Evaluator{public function Eval(expr: String): String{return eval(expr);}}}";public static object AsObject(string expression){try;public static object AsObject(string expression){trypublic static object AsObject(string expression){trytry{return type.InvokeMember("Eval", BindingFlags.InvokeMethod, null, evaluator, new object[] { expression });}catchreturn type.InvokeMember("Eval", BindingFlags.InvokeMethod, null, evaluator, new object[] { expression });}catchcatch{return null;}}public static string AsString(string expression){object o = AsObject(expression);return o == null ? null : o.ToString();}public static double? AsDouble(string expression){string s = AsString(expression);double d;return double.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out d) ? (double?)d : null;}public static int? AsInt(string expression){string s = AsString(expression);int i;return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} return null;}}public static string AsString(string expression){object o = AsObject(expression);return o == null ? null : o.ToString();}public static double? AsDouble(string expression){string s = AsString(expression);double d;return double.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out d) ? (double?)d : null;}public static int? AsInt(string expression){string s = AsString(expression);int i;return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} public static string AsString(string expression){object o = AsObject(expression);return o == null ? null : o.ToString();}public static double? AsDouble(string expression){string s = AsString(expression);double d;return double.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out d) ? (double?)d : null;}public static int? AsInt(string expression){string s = AsString(expression);int i;return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} object o = AsObject(expression);return o == null ? null : o.ToString();}public static double? AsDouble(string expression){string s = AsString(expression);double d;return double.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out d) ? (double?)d : null;}public static int? AsInt(string expression){string s = AsString(expression);int i;return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} return o == null ? null : o.ToString();}public static double? AsDouble(string expression){string s = AsString(expression);double d;return double.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out d) ? (double?)d : null;}public static int? AsInt(string expression){string s = AsString(expression);int i;return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} public static double? AsDouble(string expression){string s = AsString(expression);double d;return double.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out d) ? (double?)d : null;}public static int? AsInt(string expression){string s = AsString(expression);int i;return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} string s = AsString(expression);double d;return double.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out d) ? (double?)d : null;}public static int? AsInt(string expression){string s = AsString(expression);int i;return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} double d;return double.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out d) ? (double?)d : null;}public static int? AsInt(string expression){string s = AsString(expression);int i;return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} return double.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out d) ? (double?)d : null;}public static int? AsInt(string expression){string s = AsString(expression);int i;return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} public static int? AsInt(string expression){string s = AsString(expression);int i;return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} string s = AsString(expression);int i;return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} int i;return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;}}} 

DejanStanic
DejanStanic - petek, 04. maj 2007

using System;using System.CodeDom.Compiler;using System.Reflection;using Microsoft.JScript;namespace Infoteh.Classes.Numerics{  public static class Evaluator  {    static Evaluator()    {      CodeDomProvider cdp = new JScriptCodeProvider();      CompilerParameters cp = new CompilerParameters();      cp.GenerateInMemory = true;      CompilerResults cr = cdp.CompileAssemblyFromSource(cp, source);      Assembly assembly = cr.CompiledAssembly;      type = assembly.GetType("Evaluator.Evaluator");      evaluator = Activator.CreateInstance(type);    }    private static object evaluator = null;    private static Type type = null;    private static readonly string source = @"    package Evaluator    {      class Evaluator      {        public function Eval(expr: String): String        {          return eval(expr);        }      }    }    ";    public static object AsObject(string expression)    {      try      {        return type.InvokeMember("Eval", BindingFlags.InvokeMethod, null, evaluator, new object[] { expression });      }      catch      {        return null;      }    }    public static string AsString(string expression)    {      object o = AsObject(expression);      return o == null ? null : o.ToString();    }    public static double? AsDouble(string expression)    {      string s = AsString(expression);      double d;      return double.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out d) ? (double?)d : null;    }    public static int? AsInt(string expression)    {      string s = AsString(expression);      int i;      return int.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out i) ? (int?)i : null;    }  }}