internal static IfStatementSyntax IfIsTruthy(List <string> elementsToCheck, AST.IfType ifType)
{
var condition = CheckContextForTruthy(elementsToCheck, ifType);
if (condition == null)
{
return(null);
}
else
{
return(SF.IfStatement(condition, SF.EmptyStatement()));
}
}
internal void DoTruthyCheck(List <StatementSyntax> ifBlock, List <StatementSyntax> elseBlock = null, AST.IfType ifType = IfType.If)
{
var contextToCheck = TruthyStack.Pop();
if (contextToCheck.Symbol.SpecialType == SpecialType.System_Boolean)
{//Special treatment for boolean literals
if (contextToCheck.FullPath.Equals("true"))
{
resultStack.Peek().AddRange(ifBlock);
return;
}
if (contextToCheck.FullPath.Equals("false"))
{
if (elseBlock != null)
{
resultStack.Peek().AddRange(elseBlock);
}
return;
}
}//No boolean literal to be checked. Procede as usual
IfStatementSyntax ifStatement;
if (TruthyStack.Any())
{
ifStatement = SyntaxHelper.IfIsTruthy(GetQueryElements(TruthyStack.Peek(), contextToCheck), ifType);
}
else
{
ifStatement = SyntaxHelper.IfIsTruthy(GetQueryElements(null, contextToCheck), ifType);
}
if (ifStatement == null)
{
if (elseBlock != null)
{
AddTypeError("Unreachable 'else' Block", HandlebarsTypeErrorKind.UnreachableCode);
}
resultStack.Peek().AddRange(ifBlock);
}
else
{
if (elseBlock != null)
{
resultStack.Peek().Add(
ifStatement.WithStatement(SyntaxFactory.Block(ifBlock)).
WithElse(SyntaxFactory.ElseClause(SyntaxFactory.Block(elseBlock)))
);
}
else
{
resultStack.Peek().Add(
ifStatement.WithStatement(SyntaxFactory.Block(ifBlock)));
}
}
}
/// <summary>
/// Concats elements to a condition (e.g. (a && b && c) or (!a || !b || !c))
/// </summary>
/// <param name="elementsToCheck"></param>
/// <param name="ifType"></param>
/// <returns></returns>
private static ExpressionSyntax CheckContextForTruthy(List <string> elementsToCheck, AST.IfType ifType)
{
if (elementsToCheck == null || !elementsToCheck.Any())
{
return(null);
}
var result = ifType == AST.IfType.If ? SF.ParseExpression($"IsTruthy({elementsToCheck[0]})")
: SF.ParseExpression($"!IsTruthy({elementsToCheck[0]})");
foreach (var element in elementsToCheck.Skip(1))
{
result = ifType == AST.IfType.If ? BinaryIfIsTruthyExpression(result, element)
: BinaryUnlessIsTruthyExpression(result, element);
}
return(result);
}
