ribbons-details

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0.2.3.2. Code ribbons: the fancy stuff

Both of the above are shorthand notation for messier stuff going on underneath... Strictly speaking, the code in a particular document is made up of one or more ribbons of code. For example,

A common thing to say to the world is ``Hello, world!''
\begin{code}[hello-goodbye]

void HELLO() { printf("HELLO, WORLD!\n"); }

\end{code}


However, you might want to be less exuberant:

\begin{code}[wimp]

void hello() { printf("hello, world!\n"); }

\end{code}


And perhaps you are trying to tune out, not tune in.

\begin{code}[hello-goodbye]

void goodbye() { printf("Good-bye, cruel world...\n"); }

\end{code}

As always, code to be extracted goes inside a `\begin{code}'...`\end{code}'; the optional argument after `\begin{code}' is the name of the code-ribbon to which the program-text belongs. The example above has two ribbons, `hello-goodbye' and `wimp'. You can extract any code-ribbon(s) you wish [see `lit2pgm''s -r option]; the disjoint pieces of a particular ribbon (e.g., `hello-goodbye' above) are catenated together in the order seen.

Usually, this ribbon-business is just a bother, so there is the good ol' default ribbon, `main'. For example, the way-you-normally-write-things:

\begin{code}
void adieu() { printf("Adieu, cruel world...\n"); }

\end{code}

is actually short for:

\begin{code}[main]
void adieu() { printf("Adieu, cruel world...\n"); }

\end{code}

Unsurprisingly, `main' is the default code-ribbon when one is in the ribbon-extraction business. Similarly, code included with `>' signs in the leftmost column ("Bird tracks") is just tacked onto the `main' ribbon, too:

>void
>adieu()

>{ printf("Adieu, cruel world...\n"); }