@ -44,14 +44,14 @@ We strongly recommend to take a look at the filters table right now to see what
\subsection{Advanced}
Back to the manual? Great.\\
If you want to create your own filter you have to know exactly what do you want to get in order to translate this into the expressions. Finally, you will have to write this with correct syntax. As a result table will show only desired rows.\\
Advance subsection covers everything that you need to know in order to create any filter you may want to.
Advance subsection covers everything that you need to know in order to create any filter you may want to%TODO the filter part is actually wrong
\subsubsection{Namespaces}
Did you noticed that every default filter has ``project::`` prefix? It is a ``namespace``, a term borrowed from the C++ language. In case of OpenCS namespace of the filter determinate if the filter will be stored along with your project file or if it will be forgotten as soon as OpenCS quits.
Did you noticed that every default filter has ``project::`` prefix? It is a ``namespace``, a term borrowed from the C++ language. In case of OpenCS namespace always means scope of the said object\footnote{You are not supposed to understand this at the moment.}. But what does it mean in case of filters? Well, short explanation is actually simple.
\begin{description}
\item[project::] namespace indicates that filter is stored inside the project file.
\item[session::] namespace indicates that filter is not stored inside the project file, and once you will quit OpenCS (close session) the filter will be gone. Forever! Until then it can be found inside the filters table.
\item[project::] namespace indicates that filter is used with the project, in multiple sessions. You can restart Open{CS} and filter is still there.
\item[session::] namespace indicates that filter is not stored trough multiple sessions and once you will quit Open{CS} (close session) the filter will be gone. Forever! Until then it can be found inside the filters table.
\end{description}
In addition to this two scopes, there is a third one; called one-shot. One-shot filters are not stored anywhere and as the name implies they are supposed to be created when needed only once. Good thing about the one-shot filters is that you don't need to open filters table in order to create it. Instead you just type it directly inside the filter field, starting with ``!''.\\
In addition to this two scopes, there is a third one; called one-shot. One-shot filters are not stored (even during single session) anywhere and as the name implies they are supposed to be created when needed only once. Good thing about the one-shot filters is that you don't need to open filters table in order to create it. Instead you just type it directly inside the filter field, starting with ``!''.\\
Still, you may wonder how you are supposed to write expressions, what expressions you should use, and what syntax looks like. Let's start with nullary expressions that will allow you to create a basic filter.
\subsubsection{Nullary expressions}
@ -89,6 +89,9 @@ As you would imagine the range can be specified as including a border value, or
\item Mixing brackets is completely legal. For value equal 10, expression value(something, [5, 10) will evaluate to true. The same expression will evaluate to false for value equal 10.
\end{itemize}
\paragraph{''true`` and ''false``}
Nullary ''true`` and ''false`` do not accept any arguments, and always evaluates to true (in case of ''true``) and false (in case of ''false``) no matter what. The main usage of this expressions is the give users ability to quickly disable some part of the filter that makes heavy use of the logical expressions.
\subsubsection{Logical expressions}
This subsection takes care of two remaining groups of expressions: binary and unary. The only unary expression present in the OpenCS is logical not, while the remaining binary expressions are: or, and. This clearly makes them (from the user point of view) belonging to the same group of logical expressions.
Marek Kochanowicz
11 years ago