private SyntaxTree ParseTree(TokFlow flow)
{
while (true)
{
flow.SkipNewLines();
if (flow.IsDoneOrEof())
{
break;
}
_attributes = flow.ReadAttributes();
_startOfTheLine = flow.IsStartOfTheLine();
_exprStartPosition = flow.Current.Start;
var e = SyntaxNodeReader.ReadNodeOrNull(flow)
?? throw ErrorFactory.UnknownValueAtStartOfExpression(_exprStartPosition, flow.Current);
if (e is TypedVarDefSyntaxNode typed)
{
if (flow.IsCurrent(TokType.Def))
{
ReadEquation(typed, typed.Id);
}
else
{
ReadInputVariableSpecification(typed);
}
}
else if (flow.IsCurrent(TokType.Def) || flow.IsCurrent(TokType.Colon))
{
if (e is NamedIdSyntaxNode variable)
{
ReadEquation(variable, variable.Id);
}
//Fun call can be used as fun definition
else if (e is FunCallSyntaxNode fun && !fun.IsOperator)
{
ReadUserFunction(fun);
}
else
{
throw ErrorFactory.ExpressionBeforeTheDefinition(_exprStartPosition, e, flow.Current);
}
}