HaskellWiki:Syntax highlighting/Breakage

This page is an attempt to find a minimal criminal for the bugs in GeSHi, the syntax highlighter that powers <haskell> and <hask> on the Haskell wiki.

x == '-' || True

That breaks.

x :: String
x = map toUpper "hello"

Subsequent <haskell> blocks seem to independant of the breakages.

False || True

Looks like the (||) operator is causing the problems.

a || b

However, that works. Perhaps it only breaks when using literals?

'a' || 'b'

No, characters work too.

'a' || True

True || 'a'

5 || 'a'

'a' || 5

5 || True

True || 5

Any kind of attempt to mix literals of different types breaks.

Foo || Bar

I think any number or constructor on either side of the || makes it break.