/// <summary>
/// Visit a parse tree produced by <see cref="CustomExpressionParser.exp"/>.
/// <para>
/// The default implementation returns the result of calling <see cref="AbstractParseTreeVisitor{Result}.VisitChildren(IRuleNode)"/>
/// on <paramref name="context"/>.
/// </para>
/// </summary>
/// <param name="context">The parse tree.</param>
/// <return>The visitor result.</return>
public virtual Result VisitExp([NotNull] CustomExpressionParser.ExpContext context)
{
return(VisitChildren(context));
}
public override object VisitExp([NotNull] CustomExpressionParser.ExpContext context)
{
if (context.lit != null)
{
return(this.VisitLiteral(context.lit));
}
if (context.func != null)
{
var f = VisitExp(context.func);
var args = (context.args != null) ? VisitExpList(context.args) : Array.Empty <object>();
if (context.ptArg != null)
{
if (args is object[] o)
{
var update = new object[o.Length + 1];
for (var i = 0; i < o.Length; i++)
{
update[i] = o[i];
}
update[o.Length] = VisitPlainTextArgument(context.ptArg);
args = update;
}
else
{
throw new ArgumentException();
}
}
return(new object[]
{
"call",
f,
args
});
}
var unop = context.unop?.Text;
if (!string.IsNullOrEmpty(unop))
{
var exps = context.exp();
switch (unop)
{
case "!":
case "-":
case "+":
return(new object[] {
unop,
VisitExp(exps[0])
});
default:
throw new ArgumentException($"exp '{context.GetText()}', '{unop}'");
}
}
else
{
var op = context.op?.Text;
var exps = context.exp();
switch (op)
{
case "(":
return(VisitExp(exps[0]));
case ">=":
case "<=":
case ">":
case "<":
case "==":
case "!=":
case "+":
case "-":
case "*":
case "/":
case "%":
case ".":
return(new object[] {
op,
VisitExp(exps[0]),
VisitExp(exps[1])
});
default:
throw new ArgumentException($"exp '{context.GetText()}', '{op}'");
}
}
}
