protected override Expression OnGenerate()
{
var names = (CommonTree) Tree.Children[0];
var hasInitializers = Tree.Children.Count > 1;
if (hasInitializers)
{
var scratch = Expression.Parameter(typeof (object));
var rValueList = new CompileTimeRValueList(Tree.Children[1], t => Gen<Exp>(t), scratch);
var locals = new List<Expression>();
for (var i = 0; i < names.ChildCount; i++)
{
var name = names.Children[i].Text;
var exp = rValueList.Next();
locals.Add(GenerateDefineLocal(name, exp));
}
locals.Add(rValueList.EvalRestAndDiscard());
return Expression.Block(
typeof (void),
new[]
{
scratch
},
locals);
}
else
{
var locals = new List<Expression>();
for (var i = 0; i < names.ChildCount; i++)
{
var name = names.Children[i].Text;
locals.Add(GenerateDefineLocal(name, Expression.Constant(null, typeof (object))));
}
return Expression.Block(typeof (void), locals);
}
}
protected override Expression OnGenerate()
{
Scope = Scope.NewForEachScope();
var f = Expression.Parameter(typeof (object));
var s = Expression.Parameter(typeof (object));
var seedVar = Expression.Parameter(typeof (object));
var topScratch = Expression.Parameter(typeof (object));
var rValues = new CompileTimeRValueList(Tree.Children[2], tree => Gen<Exp>(tree), topScratch);
var assignF = Expression.Assign(f, rValues.Next());
var assignS = Expression.Assign(s, rValues.Next());
var initSeed = Expression.Assign(seedVar, rValues.Next());
var fResult = Expression.Parameter(typeof (object));
var invoke = Expression.Dynamic(InvokeBinder.New(StaticTables, new CallInfo(2)), typeof (object), f, s, seedVar);
var assignFResult = Expression.Assign(fResult, invoke);
var assignLocal = new List<Expression>();
var parameters = new List<ParameterExpression> {fResult};
var names = (CommonTree) Tree.Children[1];
for (var i = 0; i < names.Children.Count; i++)
{
var name = names.Children[i].Text;
var rValue = i == 0 ? RValueList.EmitHandleFirst(fResult) : RValueList.EmitHandleRest(fResult, i);
ParameterExpression varN;
assignLocal.Add(GenerateDefineLocal(name, rValue, out varN));
parameters.Add(varN);
}
var checkNull = Expression.Dynamic(
EqualityOperationBinder.New(StaticTables),
typeof (object),
parameters[1],
Expression.Constant(null, typeof (object)));
var checkCondition = Expression.IfThen(ToBool(checkNull), Expression.Goto(Scope.BreakTarget));
var assignSeed = Expression.Assign(seedVar, parameters[1]);
var blockTree = Tree.Children[0];
var block = Gen<Block>(blockTree);
var loopBody = Expression.Block(
typeof (void),
parameters,
assignFResult,
Expression.Block(typeof (void), assignLocal),
checkCondition,
assignSeed,
block);
var loop = Expression.Loop(loopBody, Scope.BreakTarget, Scope.ContinueTarget);
var enclosingBlock = Expression.Block(
typeof (void),
new[]
{
f,
s,
seedVar,
topScratch
},
assignF,
assignS,
initSeed,
loop);
return enclosingBlock;
}