/// <summary>
/// Called when the item is a for numerical item.
/// </summary>
/// <param name="target">The object that was passed to IParseItem.Accept.</param>
/// <returns>The passed target or a modification of it.</returns>
/// <exception cref="System.ArgumentNullException">If target is null.</exception>
public IParseItem Visit(ForNumItem target)
{
if (target == null)
throw new ArgumentNullException("target");
ILGenerator gen = compiler.CurrentGenerator;
target.Break.UserData = target.Break.UserData ?? gen.DefineLabel();
Label start = gen.DefineLabel();
Label end = (Label)target.Break.UserData;
Label sj = gen.DefineLabel(), err = gen.DefineLabel();
LocalBuilder d = compiler.CreateTemporary(typeof(double?));
LocalBuilder val = compiler.CreateTemporary(typeof(double));
LocalBuilder step = compiler.CreateTemporary(typeof(double));
LocalBuilder limit = compiler.CreateTemporary(typeof(double));
using (compiler.LocalBlock())
{
// d = {Start}.AsDouble();
target.Start.Accept(this);
gen.Emit(OpCodes.Callvirt, typeof(ILuaValue).GetMethod("AsDouble"));
gen.Emit(OpCodes.Stloc, d);
// if (d.HasValue) goto sj;
gen.Emit(OpCodes.Ldloca, d);
gen.Emit(OpCodes.Callvirt, typeof(double?).GetMethod("get_HasValue"));
gen.Emit(OpCodes.Brtrue, sj);
// err:
gen.MarkLabel(err);
// throw new InvalidOperationException("The Start, Limit, and Step of a for loop must result in numbers.");
gen.Emit(OpCodes.Ldstr, Resources.LoopMustBeNumbers);
gen.Emit(OpCodes.Newobj, typeof(InvalidOperationException).GetConstructor(new Type[] { typeof(string) }));
gen.Emit(OpCodes.Throw);
// sj:
gen.MarkLabel(sj);
// val = d.Value;
gen.Emit(OpCodes.Ldloca, d);
gen.Emit(OpCodes.Callvirt, typeof(double?).GetMethod("get_Value"));
gen.Emit(OpCodes.Stloc, val);
if (target.Step != null)
{
// d = {Step}.AsDouble();
target.Step.Accept(this);
gen.Emit(OpCodes.Callvirt, typeof(ILuaValue).GetMethod("AsDouble"));
gen.Emit(OpCodes.Stloc, d);
// if (!d.HasValue) goto err;
gen.Emit(OpCodes.Ldloca, d);
gen.Emit(OpCodes.Callvirt, typeof(double?).GetMethod("get_HasValue"));
gen.Emit(OpCodes.Brfalse, err);
// step = d.Value;
gen.Emit(OpCodes.Ldloca, d);
gen.Emit(OpCodes.Callvirt, typeof(double?).GetMethod("get_Value"));
}
else
{
// step = 1.0;
gen.Emit(OpCodes.Ldc_R8, 1.0);
}
gen.Emit(OpCodes.Stloc, step);
// d = {Limit}.AsDouble();
target.Limit.Accept(this);
gen.Emit(OpCodes.Callvirt, typeof(ILuaValue).GetMethod("AsDouble"));
gen.Emit(OpCodes.Stloc, d);
// if (!d.HasValue) goto err;
gen.Emit(OpCodes.Ldloca, d);
gen.Emit(OpCodes.Callvirt, typeof(double?).GetMethod("get_HasValue"));
gen.Emit(OpCodes.Brfalse, err);
// limit = d.Value;
gen.Emit(OpCodes.Ldloca, d);
gen.Emit(OpCodes.Callvirt, typeof(double?).GetMethod("get_Value"));
gen.Emit(OpCodes.Stloc, limit);
compiler.RemoveTemporary(d);
// start:
gen.MarkLabel(start);
// if (!((step > 0) & (val <= limit)) | ((step <= 0) & (val >= limit))) goto end;
gen.Emit(OpCodes.Ldloc, step);
gen.Emit(OpCodes.Ldc_R8, 0.0);
gen.Emit(OpCodes.Cgt);
gen.Emit(OpCodes.Ldloc, val);
gen.Emit(OpCodes.Ldloc, limit);
gen.Emit(OpCodes.Cgt);
gen.Emit(OpCodes.Ldc_I4_1);
gen.Emit(OpCodes.Xor);
gen.Emit(OpCodes.And);
gen.Emit(OpCodes.Ldloc, step);
gen.Emit(OpCodes.Ldc_R8, 0.0);
gen.Emit(OpCodes.Cgt);
gen.Emit(OpCodes.Ldc_I4_1);
gen.Emit(OpCodes.Xor);
gen.Emit(OpCodes.Ldloc, val);
gen.Emit(OpCodes.Ldloc, limit);
gen.Emit(OpCodes.Clt);
gen.Emit(OpCodes.Ldc_I4_1);
gen.Emit(OpCodes.Xor);
gen.Emit(OpCodes.And);
gen.Emit(OpCodes.Or);
gen.Emit(OpCodes.Brfalse, end);
// {name} = E.Runtime.CreateValue((object)val);
var field = compiler.DefineLocal(target.Name);
field.StartSet();
gen.Emit(OpCodes.Ldarg_1);
gen.Emit(OpCodes.Callvirt, typeof(ILuaEnvironment).GetMethod("get_Runtime"));
gen.Emit(OpCodes.Ldloc, val);
gen.Emit(OpCodes.Box, typeof(double));
gen.Emit(OpCodes.Callvirt, typeof(ILuaRuntime).GetMethod("CreateValue"));
field.EndSet();
// {Block}
target.Block.Accept(this);
// val += step;
gen.Emit(OpCodes.Ldloc, val);
gen.Emit(OpCodes.Ldloc, step);
gen.Emit(OpCodes.Add);
gen.Emit(OpCodes.Stloc, val);
compiler.RemoveTemporary(val);
compiler.RemoveTemporary(step);
compiler.RemoveTemporary(limit);
// goto start;
gen.Emit(OpCodes.Br, start);
// end:
gen.MarkLabel(end);
}
return target;
}
/// <summary>
/// Called when the item is a for numerical item.
/// </summary>
/// <param name="target">The object that was passed to IParseItem.Accept.</param>
/// <returns>The passed target or a modification of it.</returns>
/// <exception cref="System.ArgumentNullException">If target is null.</exception>
public IParseItem Visit(ForNumItem target)
{
if (target == null)
throw new ArgumentNullException("target");
using (tree.Block(true))
{
tree.DefineLocal(new[] { target.Name });
tree.DefineLabel(target.Break);
target.Block.Accept(this);
if (target.Start != null)
target.Start.Accept(this);
if (target.Limit != null)
target.Limit.Accept(this);
if (target.Step != null)
target.Step.Accept(this);
}
return target;
}
/// <summary>
/// Reads part of a numerical for loop from the input. The input is
/// currently on the equals sign '=' and the debug token currently
/// contains the parts read for the 'for' loop. 'name' contains the
/// name of the variable.
/// </summary>
/// <param name="input">Where to read input from.</param>
/// <param name="debug">The token that currently holds what was read
/// so far in the for statement and should after contain the entire loop.</param>
/// <param name="name">The token that contains the name of the variable.</param>
/// <returns>The loop object that was read.</returns>
protected virtual ForNumItem ReadNumberFor(ITokenizer input, ref Token debug, Token name)
{
// read "="
var temp = Read(input, ref debug);
if (temp.Value != "=")
throw new InvalidOperationException(string.Format(Resources.MustBeOn, "=", "ReadNumberFor"));
// get the 'start' value
var start = ReadExp(input, ref debug);
// read ','
temp = Read(input, ref debug);
if (temp.Value != ",")
throw new SyntaxException(
string.Format(Resources.TokenInvalidExpecting, temp.Value, "for", ","),
input.Name, temp);
// get the 'limit'
var limit = ReadExp(input, ref debug);
// read ','
IParseExp step = null;
if (input.Peek().Value == ",")
{
Read(input, ref debug);
// read the 'step'
step = ReadExp(input, ref debug);
}
ForNumItem i = new ForNumItem(new NameItem(name.Value) { Debug = name }, start, limit, step);
// check for 'do'
name = Read(input, ref debug);
if (name.Value != "do")
throw new SyntaxException(
string.Format(Resources.TokenInvalidExpecting, name.Value, "for", "do"),
input.Name, name);
// read the block
i.Block = ReadBlock(input, ref debug);
// read 'end'
name = Read(input, ref debug);
if (name.Value != "end")
throw new SyntaxException(
string.Format(Resources.TokenInvalidExpecting, name.Value, "for", "end"),
input.Name, name);
i.Debug = debug;
return i;
}
