enterprise-presentation/parsing.tex

\begin{frame}[fragile]
  \frametitle{Deep dive into parsing DSL syntax}

  \begin{columns}
    \begin{column}{0.3\textwidth}
      \begin{itemize}[<+>]
        \item Hand-rolled recursive-descent parser.
        \item Why not use LR parser generator?
      \end{itemize}
    \end{column}
    \begin{column}{0.5\textwidth}
      \begin{Verbatim}[fontsize=\small]
component HelloWorld {
    model {
        name: String = "",
    }

    view {
        <input bind:value="name" />
        "Hello, " {name} "!"
    }
}
      \end{Verbatim}
    \end{column}
  \end{columns}
\end{frame}

\begin{frame}[fragile]
  \frametitle{Taking advantage of Rust syntax}

  \begin{columns}
    \begin{column}{0.4\textwidth}
      \begin{Verbatim}
// proc-macro library
enum TokenTree {
    Group(Group),
    Ident(Ident),
    Punct(Punct),
    Literal(Literal),
}
      \end{Verbatim}
    \end{column}
    \begin{column}{0.4\textwidth}
      \begin{itemize}
        \item Get \texttt{\{\}}-bracketed groups for free.
        \item Easily tell identifiers from strings.
        \item Punctuation has flexible representation.
        \item Get literal parsing for free.
      \end{itemize}
    \end{column}
  \end{columns}
\end{frame}

\begin{frame}[fragile]
  \frametitle{Abstract syntax}

  \begin{center}
    \begin{BVerbatim}[fontsize=\small]
struct Component {
  name: String,
  model: ModelMap,
  view: Vec<Rsx>,
}

enum Rsx {
  Elem(Elem<Rsx>),
  Code(Context, Expr),
  Text(String),
  ForLoop(Pat, Expr, Type, Vec<Rsx>),
}

...
    \end{BVerbatim}
  \end{center}
\end{frame}

\begin{frame}
  \frametitle{Checking your work.. with property testing}

  \begin{itemize}[<+>]
    \item Define certain properties about the procedures.
    \item Define types of data that can be passed in.
    \item Create "strategies" for randomly generating complex data.
    \item Computer generates input cases based on the strategies.
    \item Bonus: input cases are "shrunk" down to the minimal case.
  \end{itemize}
\end{frame}

\begin{frame}[fragile]
  \frametitle{Property testing example}

  \begin{Verbatim}[fontsize=\small]
proptest! {
  #[test]
  fn tokens_parse_compatibility(tree in arbitrary_component()) {
    // turn the input tree into tokens and back
    let tokens = tree.to_token_stream();
    let mut visitor = Visitor::from_tokens(tokens.clone());
    let tree2 = visitor.next().unwrap().unwrap();

    // compare the trees
    prop_assert_eq!(tree.name, tree2.name);
    prop_assert_eq!(tree.model, tree2.model);
    prop_assert_eq!(tree.view, tree2.view);
  }
}
  \end{Verbatim}
\end{frame}