private int GenerateReference(AstReference ast)
{
if (ast.IsLocal)
{
// Local case
var dst = ReferenceLocal(ast.Identifier);
return(dst);
}
else if (ast.IsGlobal)
{
// R(A) := G[K(Bx)]
var dst = Push();
var name = ast.Identifier;
var litIdx = DefineLiteral(new Value(name));
var litIdxCur = Variables[ast.VarIdx].LitIdx;
if (litIdxCur < 0)
{
var var = Variables[ast.VarIdx];
var.LitIdx = litIdx;
Variables[ast.VarIdx] = var;
}
else if (litIdxCur != litIdx)
{
throw new System.Exception();
}
AddABX(OpCode.GETGLOBAL, dst, ast.VarIdx);
return(dst);
}
else if (ast.IsUpValue)
{
var envIdx = (byte)ast.UpEnvIdx;
var varIdx = (byte)ast.UpVarIdx;
//if (envIdx > 0)
//{
// UpValue case
// R(A) := U[B]
var dst = Push();
AddAB(OpCode.GETUPVAL, dst, 0);
return(dst);
//}
//else
//{
//}
}
else
{
throw new System.Exception();
}
}
public static bool TryMatchCall(this AstNode node, out AstIndirectCall indirectCallNode,
out AstReference referenceNode, out EntityRef entityRef)
{
if ((indirectCallNode = node as AstIndirectCall) != null
&& (referenceNode = indirectCallNode.Subject as AstReference) != null)
{
entityRef = referenceNode.Entity;
return true;
}
else
{
referenceNode = null;
entityRef = null;
return false;
}
}
/// <summary>
/// Emits code responsible for changing the variables identity.
/// </summary>
/// <param name = "target">The target to compile to</param>
private void _emitNewDeclareCode(CompilerTarget target)
{
_ensureValid();
//create command call
// unbind(->variable)
var unlinkCall = new AstIndirectCall(Position, PCall.Get,
new AstReference(Position, EntityRef.Command.Create(Engine.UnbindAlias)));
var targetRef = new AstReference(Position, EntityRef.Variable.Local.Create(Id));
unlinkCall.Arguments.Add(targetRef);
//Optimize call and emit code
var call = (AstExpr) unlinkCall;
_OptimizeNode(target, ref call);
call.EmitEffectCode(target);
}
public static bool TryMatchCall(this AstNode node,
out AstReference referenceNode, out EntityRef entityRef)
{
AstIndirectCall indirectCallNode;
return TryMatchCall(node, out indirectCallNode, out referenceNode, out entityRef);
}
