/// <summary>
/// Given the body of an iterator method <paramref name="body"/>, this method try to compile its body.
///
/// Specifically, this method:
/// 1) creates a closure class that implements: IEnumerator, generic and nongeneric versions,
/// IEnumerable, generic and nongeneric versions, and IDisposable. The generic versions of IEnumerator
/// and IEnumerator is instantiated by a type T that is used to instantiate the return type of
/// the iterator method. The members of the closure class include:
/// 1.1) fields corresponding to every parameter and local variables.
/// 1.2) fields that manages the state machine: __current and __state, and a currentThreadId field.
/// 1.3) a constructor that takes one int argument.
/// 1.4) methods that are required by the interfaces of the closure class: MoveNext, Reset,
/// GetEnumerator, Current getter, and DisposeMethod. (GetEnumerator is needed only if the iterator's type is IEnumerable and not IEnumerator.)
/// 2) creates the new body of the iterator method: which returns a local variable that holds a new object of the closure class, with the fields of
/// the closure class that correspond to the parameters (including the self parameter if applicable)
/// initialized.
/// 3) transforms the body, which should now not contain any annonymous delegates, into the body of the
/// MoveNext method of the closure class. This includes:
/// 3.1) every local/parameter reference -> this.field reference
/// 3.2) every yield return or yield break -> assignment to current and return true or false, respectively.
/// 3.3) a switch statement for the state machine, with state values corresponds to each yield return/yield break
/// 3.4) a try block if an iterator is created in the body.
/// 4) If the iterator method has a type parameter, so will the closure class. Make sure in the closure class only
/// the right type parameter is referenced.
/// </summary>
/// <param name="body">The method body to be normalized</param>
/// <param name="method">Method definition that owns the body</param>
/// <param name="privateHelperTypes">List of helper types generated when compiling <paramref name="method">method</paramref>/></param>
/// <returns></returns>
private BlockStatement GetNormalizedIteratorBody(IBlockStatement body, IMethodDefinition method, List<ITypeDefinition> privateHelperTypes) {
IteratorClosureGenerator iteratorClosureGenerator = new IteratorClosureGenerator(method, privateHelperTypes, this.host, this.sourceLocationProvider);
return iteratorClosureGenerator.CompileIterator(body);
}
