/// <summary>
/// Exit a parse tree produced by the <c>booleanExpr</c>
/// labeled alternative in <see cref="KittenGrammarParser.expr"/>.
/// <para>The default implementation does nothing.</para>
/// </summary>
/// <param name="context">The parse tree.</param>
public virtual void ExitBooleanExpr([NotNull] KittenGrammarParser.BooleanExprContext context)
{
}
public override DynObj VisitBooleanExpr([NotNull] KittenGrammarParser.BooleanExprContext context)
{
var LHS = Visit(context.left);
var RHS = Visit(context.right);
var op = context.op.Text;
if (LHS.t == RHS.t)
{
if (LHS.t == vType.Number)
{
switch (op)
{
case "==":
return(DBool(LHS.NumberVal == RHS.NumberVal));
case "!=":
return(DBool(LHS.NumberVal != RHS.NumberVal));
case ">=":
return(DBool(LHS.NumberVal >= RHS.NumberVal));
case "<=":
return(DBool(LHS.NumberVal <= RHS.NumberVal));
case ">":
return(DBool(LHS.NumberVal > RHS.NumberVal));
case "<":
return(DBool(LHS.NumberVal < RHS.NumberVal));
}
}
if (LHS.t == vType.Bool)
{
switch (op)
{
case "==":
return(DBool(LHS.BoolVal == RHS.BoolVal));
case "!=":
return(DBool(LHS.BoolVal != RHS.BoolVal));
default:
ReportError("InvalidOperatorError", $"operator {op} used in LHS and RHS type {LHS.typeName}", context.start.Line);
break;
}
}
if (LHS.t == vType.String)
{
switch (op)
{
case "==":
return(DBool(LHS.StringVal == RHS.StringVal));
case "!=":
return(DBool(LHS.StringVal != RHS.StringVal));
default:
ReportError("InvalidOperatorError", $"operator {op} used in LHS and RHS type {LHS.typeName}", context.start.Line);
break;
}
}
if (LHS.t == vType.Null)
{
switch (op)
{
case "==":
return(DBool(true));
case "!=":
return(DBool(false));
default:
ReportError("InvalidOperatorError", $"operator {op} used in LHS and RHS type {LHS.typeName}", context.start.Line);
break;
}
}
}
else
{
ReportError("InvalidTypeError", $"LHS type {LHS.typeName} and RHS type {RHS.typeName} used on operator \"{op}\"", context.start.Line);
}
return(base.VisitBooleanExpr(context));
}
/// <summary>
/// Visit a parse tree produced by the <c>booleanExpr</c>
/// labeled alternative in <see cref="KittenGrammarParser.expr"/>.
/// <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 VisitBooleanExpr([NotNull] KittenGrammarParser.BooleanExprContext context)
{
return(VisitChildren(context));
}