private static Expression GenerateForLoop(LoopScope loopScope, Token tStart, List<ParameterExpression> loopVars, Expression[] explist)
{
const string csFunc = "#f";
const string csState = "#s";
const string csVar = "#var";
ParameterExpression varTmp = Expression.Variable(typeof(LuaResult), "#tmp");
ParameterExpression varFunc = Expression.Variable(explist.Length > 0 && typeof(Delegate).GetTypeInfo().IsAssignableFrom(explist[0].Type.GetTypeInfo()) ? explist[0].Type : typeof(object), csFunc);
ParameterExpression varState = Expression.Variable(typeof(object), csState);
ParameterExpression varVar = Expression.Variable(typeof(object), csVar);
// local var1, ..., varn = tmp;
for (int i = 0; i < loopVars.Count; i++)
loopScope.InsertExpression(i, Expression.Assign(loopVars[i], ConvertExpression(loopScope.Runtime, tStart, GetResultExpression(loopScope.Runtime, tStart, varTmp, i), loopVars[i].Type)));
return Expression.Block(new ParameterExpression[] { varTmp, varFunc, varState, varVar },
// fill the local loop variables initial
// local #f, #s, #var = explist
Expression.Assign(varTmp, GetLuaResultExpression(loopScope, tStart, explist)),
Expression.Assign(varFunc, ConvertExpression(loopScope.Runtime, tStart, GetResultExpression(loopScope.Runtime, tStart, varTmp, 0), varFunc.Type)),
Expression.Assign(varState, GetResultExpression(loopScope.Runtime, tStart, varTmp, 1)),
Expression.Assign(varVar, GetResultExpression(loopScope.Runtime, tStart, varTmp, 2)),
Expression.Label(loopScope.ContinueLabel),
// local tmp = f(s, var)
Expression.Assign(varTmp, InvokeExpression(loopScope, tStart, varFunc, InvokeResult.LuaResult,
new ArgumentsList(varState, varVar), true)
),
// var = tmp[0]
Expression.Assign(varVar, GetResultExpression(loopScope.Runtime, tStart, varTmp, 0)),
// if var == nil then goto break;
Expression.IfThenElse(Expression.Equal(varVar, Expression.Constant(null, typeof(object))),
Expression.Goto(loopScope.BreakLabel),
loopScope.ExpressionBlock), // LoopBody
Expression.Goto(loopScope.ContinueLabel),
Expression.Label(loopScope.BreakLabel)
);
}
private static void ParseForEachLoop(Scope scope, LuaLexer code)
{
ParameterExpression varEnumerable = Expression.Variable(typeof(System.Collections.IEnumerable), "#enumerable");
ParameterExpression varEnumerator = Expression.Variable(typeof(System.Collections.IEnumerator), "#enumerator");
// foreach name in exp do block end;
code.Next(); // foreach
// fetch the loop variable
LoopScope loopScope = new LoopScope(scope);
Token tLoopVar;
Type typeLoopVar;
ParseIdentifierAndType(scope, code, out tLoopVar, out typeLoopVar);
ParameterExpression loopVar = loopScope.RegisterVariable(typeLoopVar, tLoopVar.Value);
// get the enumerable expression
FetchToken(LuaToken.KwIn, code);
Expression exprEnum = Lua.EnsureType(ParseExpression(scope, code, InvokeResult.None, scope.EmitExpressionDebug), typeof(object));
// parse the loop body
FetchToken(LuaToken.KwDo, code);
ParseBlock(loopScope, code);
FetchToken(LuaToken.KwEnd, code);
loopScope.InsertExpression(0, Expression.Assign(loopVar, ConvertExpression(scope.Runtime, tLoopVar, Expression.Property(varEnumerator, Lua.EnumeratorCurrentPropertyInfo), loopVar.Type)));
scope.AddExpression(
Expression.Block(new ParameterExpression[] { varEnumerable, varEnumerator, loopVar },
// local enumerable = exprEnum as IEnumerator
Expression.Assign(varEnumerable, Expression.TypeAs(exprEnum, typeof(System.Collections.IEnumerable))),
// if enumerable == nil then error
Expression.IfThen(Expression.Equal(varEnumerable, Expression.Constant(null, typeof(object))), Lua.ThrowExpression(Properties.Resources.rsExpressionNotEnumerable)),
// local enum = exprEnum.GetEnumerator()
Expression.Assign(varEnumerator, Expression.Call(varEnumerable, Lua.EnumerableGetEnumeratorMethodInfo)),
// while enum.MoveNext() do
Expression.Label(loopScope.ContinueLabel),
Expression.IfThenElse(Expression.Call(varEnumerator, Lua.EnumeratorMoveNextMethodInfo), Expression.Empty(), Expression.Goto(loopScope.BreakLabel)),
// loopVar = enum.Current
loopScope.ExpressionBlock,
// end;
Expression.Goto(loopScope.ContinueLabel),
Expression.Label(loopScope.BreakLabel)
));
}
private static Expression GenerateForLoop(LoopScope loopScope, Token tStart, ParameterExpression loopVar, Expression loopStart, Expression loopEnd, Expression loopStep)
{
const string csVar = "#var";
const string csEnd = "#end";
const string csStep = "#step";
ParameterExpression internLoopVar = Expression.Variable(loopVar.Type, csVar);
ParameterExpression endVar = Expression.Variable(loopEnd.Type, csEnd);
ParameterExpression stepVar = Expression.Variable(loopStep.Type, csStep);
LabelTarget labelLoop = Expression.Label("#loop");
// Erzeuge CodeBlock
loopScope.InsertExpression(0, Expression.Assign(loopVar, internLoopVar));
// Erzeuge den Schleifenblock
return Expression.Block(new ParameterExpression[] { internLoopVar, endVar, stepVar },
Expression.Assign(internLoopVar, ConvertExpression(loopScope.Runtime, tStart, loopStart, internLoopVar.Type)),
Expression.Assign(endVar, loopEnd),
Expression.Assign(stepVar, loopStep),
Expression.Label(labelLoop),
Expression.IfThenElse(
BinaryOperationExpression(loopScope.Runtime, tStart, ExpressionType.OrElse,
BinaryOperationExpression(loopScope.Runtime, tStart, ExpressionType.AndAlso,
ConvertExpression(loopScope.Runtime, tStart, BinaryOperationExpression(loopScope.Runtime, tStart, ExpressionType.GreaterThan, stepVar, Expression.Constant(0, typeof(int))), typeof(bool)),
ConvertExpression(loopScope.Runtime, tStart, BinaryOperationExpression(loopScope.Runtime, tStart, ExpressionType.LessThanOrEqual, internLoopVar, endVar), typeof(bool))
),
BinaryOperationExpression(loopScope.Runtime, tStart, ExpressionType.AndAlso,
ConvertExpression(loopScope.Runtime, tStart, BinaryOperationExpression(loopScope.Runtime, tStart, ExpressionType.LessThanOrEqual, stepVar, Expression.Constant(0, typeof(int))), typeof(bool)),
ConvertExpression(loopScope.Runtime, tStart, BinaryOperationExpression(loopScope.Runtime, tStart, ExpressionType.GreaterThanOrEqual, internLoopVar, endVar), typeof(bool))
)
),
loopScope.ExpressionBlock,
Expression.Goto(loopScope.BreakLabel)
),
Expression.Label(loopScope.ContinueLabel),
Expression.Assign(internLoopVar, ConvertExpression(loopScope.Runtime, tStart, BinaryOperationExpression(loopScope.Runtime, tStart, ExpressionType.Add, internLoopVar, stepVar), internLoopVar.Type)),
Expression.Goto(labelLoop),
Expression.Label(loopScope.BreakLabel)
);
}