/// <summary>
/// Creates a new class expression.
/// </summary>
/// <param name="scope"> The scope that contains the class. </param>
/// <param name="name"> The class name. </param>
/// <param name="extends"> The base class, or <c>null</c> if this class doesn't inherit
/// from another class. </param>
/// <param name="constructor"> The constructor, or <c>null</c> if the class doesn't have one. </param>
/// <param name="members"> A list of class members. </param>
public ClassExpression(Scope scope, string name, Expression extends, FunctionExpression constructor, List <FunctionExpression> members)
{
this.Scope = scope ?? throw new ArgumentNullException(nameof(scope));
this.Name = name;
this.Extends = extends;
this.Constructor = constructor;
this.Members = members ?? throw new ArgumentNullException(nameof(members));
}
/// <summary>
/// Declares a variable or function in this scope. This will be initialized with the value
/// of the given expression.
/// </summary>
/// <param name="keyword"> The keyword that was used to declare the variable (var, let or
/// const). </param>
/// <param name="name"> The name of the variable. </param>
/// <param name="hoistedFunction"> The function value to hoist to the top of the scope.
/// Should be <c>null</c> for everything except function declarations. </param>
/// <returns> A reference to the variable that was declared. </returns>
internal void DeclareVariable(KeywordToken keyword, string name, FunctionExpression hoistedFunction = null)
{
if (name == null)
{
throw new ArgumentNullException(nameof(name));
}
// If variables cannot be declared in the scope, try the parent scope instead.
var declarationScope = this;
if (keyword == KeywordToken.Var)
{
while (declarationScope != null && (declarationScope.Type == ScopeType.Block || declarationScope.Type == ScopeType.With))
{
declarationScope = declarationScope.ParentScope;
}
}
if (declarationScope != null && !declarationScope.variables.ContainsKey(name))
{
// This is a local variable that has not been declared before.
var variable = new DeclaredVariable()
{
Scope = declarationScope,
Index = declarationScope.variables.Count,
Keyword = keyword,
Name = name,
};
declarationScope.variables.Add(name, variable);
}
if (hoistedFunction != null)
{
var hoistedScope = this;
while (hoistedScope != null && hoistedScope.Type == ScopeType.Block)
{
hoistedScope = hoistedScope.ParentScope;
}
if (hoistedScope.hoistedFunctions == null)
{
hoistedScope.hoistedFunctions = new Dictionary <string, FunctionExpression>();
}
hoistedScope.hoistedFunctions[name] = hoistedFunction;
}
}