/// <summary>
/// Assign a value to an expression.
/// </summary>
/// <param name="expr">The assignment expressions</param>
/// <returns></returns>
public object VisitAssign(AssignExpr expr)
{
var ctx = expr.Ctx;
var varExpr = expr.VarExp;
var valueExpr = expr.ValueExp;
var node = expr;
var isDeclaration = expr.IsDeclaration;
// CASE 1: Assign variable. a = 1
if (varExpr.IsNodeType(NodeTypes.SysVariable))
{
AssignHelper.SetVariableValue(ctx, this, node, isDeclaration, varExpr, valueExpr);
}
// CASE 2: Assign member.
// e.g. dictionary : user.name = 'kishore'
// e.g. property on class: user.age = 20
else if (varExpr.IsNodeType(NodeTypes.SysMemberAccess))
{
AssignHelper.SetMemberValue(ctx, this, node, varExpr, valueExpr);
}
// Case 3: Assign value to index: "users[0]" = <expression>;
else if (varExpr.IsNodeType(NodeTypes.SysIndex))
{
AssignHelper.SetIndexValue(ctx, this, node, varExpr, valueExpr);
}
return LObjects.Null;
}
/// <summary>
/// Creates a unary expression with symbol scope, context, script refernce set.
/// </summary>
/// <param name="name"></param>
/// <param name="token"></param>
/// <returns></returns>
public static Expr Assign(bool declare, Expr left, Expr right, TokenData token)
{
var exp = new AssignExpr();
exp.IsDeclaration = declare;
exp.VarExp = left;
exp.ValueExp = right;
SetupContext(exp, token);
return exp;
}
/// <summary>
/// Visits the var statement tree.
/// </summary>
/// <param name="expr"></param>
public object VisitAssign(AssignExpr expr)
{
_callBackOnNodeStart(expr);
expr.VarExp.Visit(this);
if (expr.ValueExp != null)
expr.ValueExp.Visit(this);
return null;
}