public static Expression Assign(Expression left, Expression right)
{
GlobalVariableExpression assignable = left as GlobalVariableExpression;
if (assignable != null)
{
return(new AssignmentExtensionExpression(left, right));
}
return(Expression.Assign(left, right));
}
protected override Expression RewriteGet(GlobalVariableExpression node) {
EnsureUniqueName(node);
return AstUtils.Convert(
Expression.Call(
typeof(ScriptingRuntimeHelpers).GetMethod(node.IsLocal ? "LookupName" : "LookupGlobalName"),
new Expression[]{
Context,
AstUtils.Constant(SymbolTable.StringToId(node.Name))
}
),
node.Type
);
}
protected Expression MapToExpression(GlobalVariableExpression variable) {
Expression result;
if (_mapToExpression.TryGetValue(variable, out result)) {
return result;
}
EnsureUniqueName(_globalNames, variable);
result = Expression.Property(
MakeWrapper(variable),
typeof(ModuleGlobalWrapper).GetProperty("CurrentValue")
);
return _mapToExpression[variable] = result;
}
protected abstract Expression RewriteGet(GlobalVariableExpression node);
protected static void EnsureUniqueName(IDictionary<string, GlobalVariableExpression> varsByName, GlobalVariableExpression node) {
GlobalVariableExpression n2;
if (varsByName.TryGetValue(node.Name, out n2)) {
if (node == n2) {
return;
}
throw Error.GlobalsMustBeUnique();
}
varsByName.Add(node.Name, node);
}
private Expression RewriteGet(GlobalVariableExpression node) {
if (_wrappers == null) {
return new LookupNameExpression(node.IsLocal, SymbolTable.StringToId(node.Name), Context);
} else {
return new GlobalGetExpression(GetWrapper(node));
}
}
private ModuleGlobalWrapper GetWrapper(GlobalVariableExpression node) {
ModuleGlobalWrapper ret;
if (!_wrappers.TryGetValue(node, out ret)) {
ret = new ModuleGlobalWrapper(_codeContext, SymbolTable.StringToId(node.Name));
_wrappers[node] = ret;
}
return ret;
}
private void EnsureUniqueName(GlobalVariableExpression node) {
EnsureUniqueName(node.IsLocal ? _localNames : _globalNames, node);
}
protected override Expression RewriteGet(GlobalVariableExpression node) {
return AstUtils.Convert(MapToExpression(node), node.Type);
}
protected abstract Expression MakeWrapper(GlobalVariableExpression variable);
