public void Visit(Ast.Stmt.Return r)
{
Visit(r.Item.Expr.Value);
Ast.Stmt.Funcdef fd = (Ast.Stmt.Funcdef)r.Item.Decl.Value;
Ast.Expr e = r.Item.Expr.Value;
if (fd.Item.Formal.Type != e.ActualType)
{
m_errorList.Add("Type Error: Cannot return " + e.ActualType +
" from function " + fd.Item.Formal.Name +
" returning " + fd.Item.Formal.Type);
}
}
public object EvaluateExpr(Ast.Expr expr, ScriptEnv env)
{
using var dt = _notebook.Query($"SELECT ({expr.Sql})", env.Vars);
if (dt.Columns.Count == 1 && dt.Rows.Count == 1)
{
return(dt.Rows[0][0]);
}
else
{
throw new ScriptException(
$"Evaluation of expression \"{expr.Sql}\" did not produce a value.");
}
}
public T EvaluateExpr <T>(Ast.Expr expr, ScriptEnv env)
{
var value = EvaluateExpr(expr, env);
if (typeof(T).IsAssignableFrom(value.GetType()))
{
return((T)value);
}
else
{
throw new ScriptException(
$"Evaluation of expression \"{expr.Sql}\" produced a value of type " +
$"\"{value.GetType().Name}\" instead of the expected \"{typeof(T).Name}\".");
}
}
private void Visit(Ast.Expr e)
{
switch (e)
{
case Ast.Expr.VarRef v:
Visit(v);
break;
case Ast.Expr.Int i:
Visit(i);
break;
case Ast.Expr.Float f:
Visit(f);
break;
case Ast.Expr.String s:
Visit(s);
break;
case Ast.Expr.Bool b:
Visit(b);
break;
case Ast.Expr.FuncCall f:
Visit(f);
break;
case Ast.Expr.BinOp b:
Visit(b);
break;
case Ast.Expr.UnOp u:
Visit(u);
break;
}
}