// Lazy evaluation
public static FormulaValue Or(EvalVisitor runner, SymbolContext symbolContext, IRContext irContext, FormulaValue[] args)
{
foreach (var arg in args)
{
var res = runner.EvalArg <BooleanValue>(arg, symbolContext, arg.IRContext);
if (res.IsValue)
{
var val = res.Value;
if (val.Value)
{
return(new BooleanValue(irContext, true));
}
}
else if (res.IsError)
{
return(res.Error);
}
}
return(new BooleanValue(irContext, false));
}
// https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/functions/function-isblank-isempty
// Take first non-blank value.
//
public static FormulaValue Coalesce(EvalVisitor runner, SymbolContext symbolContext, IRContext irContext, FormulaValue[] args)
{
var errors = new List <ErrorValue>();
foreach (var arg in args)
{
var res = runner.EvalArg <ValidFormulaValue>(arg, symbolContext, arg.IRContext);
if (res.IsValue)
{
var val = res.Value;
if (!(val is StringValue str && str.Value == ""))
{
if (errors.Count == 0)
{
return(res.ToFormulaValue());
}
else
{
return(ErrorValue.Combine(irContext, errors));
}
}
}
if (res.IsError)
{
errors.Add(res.Error);
}
}
if (errors.Count == 0)
{
return(new BlankValue(irContext));
}
else
{
return(ErrorValue.Combine(irContext, errors));
}
}