/// <summary>
/// Executes the given source code. Execution is bound to the global scope.
/// </summary>
/// <param name="source"> The javascript source code to execute. </param>
/// <returns> The result of executing the source code. </returns>
/// <exception cref="ArgumentNullException"> <paramref name="code"/> is a <c>null</c> reference. </exception>
public object Evaluate(ScriptSource source)
{
var methodGen = new Jurassic.Compiler.EvalMethodGenerator(
this, // The script engine
this.CreateGlobalScope(), // The variable scope.
source, // The source code.
CreateOptions(), // The compiler options.
this.Global); // The value of the "this" keyword.
// Parse
if (this.ParsingStarted != null)
{
this.ParsingStarted(this, EventArgs.Empty);
}
methodGen.Parse();
// Optimize
if (this.OptimizationStarted != null)
{
this.OptimizationStarted(this, EventArgs.Empty);
}
methodGen.Optimize();
// Generate code
if (this.CodeGenerationStarted != null)
{
this.CodeGenerationStarted(this, EventArgs.Empty);
}
methodGen.GenerateCode();
VerifyGeneratedCode();
// Execute
if (this.ExecutionStarted != null)
{
this.ExecutionStarted(this, EventArgs.Empty);
}
var result = methodGen.Execute();
// Normalize the result (convert null to Undefined, double to int, etc).
return(TypeUtilities.NormalizeValue(result));
}
// EVAL SUPPORT
//_________________________________________________________________________________________
//private class EvalCacheKey
//{
// public string Code;
// public Compiler.Scope Scope;
// public bool StrictMode;
// public override int GetHashCode()
// {
// int bitValue = 1;
// int hashCode = this.Code.GetHashCode();
// var scope = this.Scope;
// do
// {
// if (scope is Compiler.DeclarativeScope)
// hashCode ^= bitValue;
// scope = scope.ParentScope;
// bitValue *= 2;
// } while (scope != null);
// if (this.StrictMode == true)
// hashCode ^= bitValue;
// return hashCode;
// }
// public override bool Equals(object obj)
// {
// if ((obj is EvalCacheKey) == false)
// return false;
// var other = (EvalCacheKey) obj;
// if (this.Code != other.Code ||
// this.StrictMode != other.StrictMode)
// return false;
// var scope1 = this.Scope;
// var scope2 = other.Scope;
// do
// {
// if (scope1.GetType() != scope2.GetType())
// return false;
// scope1 = scope1.ParentScope;
// scope2 = scope2.ParentScope;
// if (scope1 == null && scope2 != null)
// return false;
// if (scope1 != null && scope2 == null)
// return false;
// } while (scope1 != null);
// return true;
// }
//}
//private Dictionary<EvalCacheKey, WeakReference> evalCache =
// new Dictionary<EvalCacheKey, WeakReference>();
/// <summary>
/// Evaluates the given javascript source code and returns the result.
/// </summary>
/// <param name="code"> The source code to evaluate. </param>
/// <param name="scope"> The containing scope. </param>
/// <param name="thisObject"> The value of the "this" keyword in the containing scope. </param>
/// <param name="strictMode"> Indicates whether the eval statement is being called from
/// strict mode code. </param>
/// <returns> The value of the last statement that was executed, or <c>undefined</c> if
/// there were no executed statements. </returns>
internal object Eval(string code, Compiler.Scope scope, object thisObject, bool strictMode)
{
// Check if the cache contains the eval already.
//var key = new EvalCacheKey() { Code = code, Scope = scope, StrictMode = strictMode };
//WeakReference cachedEvalGenRef;
//if (evalCache.TryGetValue(key, out cachedEvalGenRef) == true)
//{
// var cachedEvalGen = (Compiler.EvalMethodGenerator)cachedEvalGenRef.Target;
// if (cachedEvalGen != null)
// {
// // Replace the "this object" before running.
// cachedEvalGen.ThisObject = thisObject;
// // Execute the cached code.
// return ((Compiler.EvalMethodGenerator)cachedEvalGen).Execute();
// }
//}
// Parse the eval string into an AST.
var options = new Compiler.CompilerOptions()
{
ForceStrictMode = strictMode
};
var evalGen = new Jurassic.Compiler.EvalMethodGenerator(
this, // The script engine.
scope, // The scope to run the code in.
new StringScriptSource(code), // The source code to execute.
options, // Options.
thisObject); // The value of the "this" keyword.
// Make sure the eval cache doesn't get too big. TODO: add some sort of LRU strategy?
//if (evalCache.Count > 100)
// evalCache.Clear();
//// Add the eval method generator to the cache.
//evalCache[key] = new WeakReference(evalGen);
// Compile and run the eval code.
return(evalGen.Execute());
}
