FW: Clarification of \begin{code} ... \end{code} stuff

[Simon Peyton-Jones]

> In the thread "Literate scripts not handled correctly" Simon Marlow
> said:
>=20
> > Yes, it looks like GHC's unlit program removes whitespace when=20
> > looking for \begin{code}, but not for \end{code}.  The report isn't=20
> > explicit about whether whitespace is allowed on these lines, but I=20
> > would tend to the view that it isn't.
>=20
> Can you please clarify this in the report [...]

I'm sure the "\begin{code}" and "\end{code}" should
be at the beginning of a line.   Whether anything else should be allowed
on that line is moot.  Maybe not.   What would the layout be for this?
	\begin{code} f x =3D x
	\end{code}

On the other hand it would be painful if a block of code was omitted
because
of a trailing space on the \begin{code} line; an easy error.

I therefore propose code starts on the line *following* a line beginning
with \begin{code}.  And similarly stops on a line beginning \end{code}.

For Ian's snippet:

    \begin{code}

    foo =3D "hello\
    \end{code}"

    \end{code}

I think it's clear that the first \end{code} should be scanned as part
of the string literal.

Simon